| 词或词组 | 中文 | 英文解释中文解释 |
|---|---|---|
| Design stress (Unit Pa) | 设计应力（单位Pa） |
The greatest allowable stress in a component or structure that will not result in failure under normal operating conditions. 在正常操作条件下不会导致失效的部件或结构中的最大许用应力。 |
| Brittle fracture | 脆性断裂 |
The fracture of a component or structure in the globally-elastic range of loading, so that the broken pieces may be refitted to regain the original article. Separation of a solid accompanied by little or no macroscopic plastic deformation. Typically, brittle fracture occurs by rapid crack propagation with less expenditure of energy than for ductile fracture. 部件或结构在全局弹性载荷范围内的断裂，以便可以将破碎的碎片重新装配以恢复原始物品。固体的分离伴随着很少或没有宏观塑性变形。通常，脆性断裂通过快速裂纹扩展发生，能量消耗比韧性断裂少。 |
| Rockwell superficial hardness test | 洛氏表面硬度试验 |
Same as Rockwell hardness test, except that smaller minor and major loads are used. 与洛氏硬度测试相同，只是使用较小的次要载荷和主要载荷。 |
| Mechanical properties of solid materials | 固体材料的力学性能 |
The strength and stiffness properties of solid materials such as fracture toughness, the moduli of elasticity, percent elongation, 固体材料的强度和刚度特性，例如断裂韧性、弹性模量、伸长率、 |
| Sigma phase | σ相 |
A hard, brittle, nonmagnetic intermediate phase with a tetragonal crystal structure, containing 30 atoms per unit cell, space group P42/mnm, occurring in many binary and ternary alloys of the transition elements. The composition of this phase in the various systems is not the same, and the phase usually exhibits a wide range in homogeneity. Alloying with a third transition element usually enlarges the field of homogeneity and extends it deep into the ternary section. 一种硬、脆、非磁性中间相，具有四方晶体结构，每单位晶胞含有30个原子，空间群P42/mnm，存在于许多过渡元素的二元和三元合金中。该相在各种系统中的组成不尽相同，并且该相通常表现出宽范围的均匀性。与第三过渡元素的合金化通常会扩大均匀性范围，并将其延伸到三元区。 |
| Crack length (depth) (a) | 裂纹长度（深度）（a） |
In fatigue and stress corrosion cracking, the physical crack size used to determine the crack growth rate and the stress-intensity factor. For the compact-type specimen, crack length is measured from the line connecting the bearing points of load application. For the center-cracked-tension specimen, crack length is measured from the perpendicular bisector of the central crack. 在疲劳和应力腐蚀裂纹中，用于确定裂纹扩展速率和应力强度因子的物理裂纹尺寸。对于紧凑型试样，裂纹长度从连接载荷施加点的线开始测量。对于中心裂纹拉伸试样，从中心裂纹的垂直平分线测量裂纹长度。 |
| Thermoelectric material | 热电材料 |
A material in which any of the thermoelectric phenomena, such as the Peltier, Seebeck, and Thomson effects, are especially strong. 一种热电现象特别强烈的材料，如珀尔帖效应、塞贝克效应和汤姆森效应。 |
| Wing nut | 蝶形螺母 |
A nut having two opposite protruding wings to permit hand tightening. 一种螺母，有两个相对突出的翼片，可以用手拧紧。 |
| Creep rupture strength (Unit Pa) | 蠕变断裂强度（单位Pa） |
The fracture stress at the end of a creep test in metals and polymers, often plotted against time to give a stress-rupture curve. 金属和聚合物蠕变试验结束时的断裂应力，通常与时间作图以给出应力-断裂曲线。 |
| Absolute stability | 绝对稳定 |
Condtion of a linear system in which there exists a limiting value of the open-loop gain such that the system is stable for all lower values of that gain, and unstable for all higher values. 线性系统的条件，其中存在开环增益的限制值，使得系统对于该增益的所有较低值都是稳定的，而对于所有较高值来说都是不稳定的。 |
| Working section | 工作区 |
That part of a wind tunnel in which models are placed for testing, or where detailed measurements are performed. 风洞中放置模型进行测试或进行详细测量的部分。 |
| Fracture strength | 断裂强度 |
(fracture stress) (Unit Pa) The stress at which a material breaks. It is not absolute for a given material, as it depends on the laws of fracture mechanics and is size-dependent. （断裂应力）（单位Pa）材料断裂时的应力。对于给定的材料，它不是绝对的，因为它取决于断裂力学定律，并且取决于尺寸。 |
| Turbomolecular pump | 涡轮分子泵 |
A high-vacuum (pressure down to about 10−8 Pa) pump in which momentum is transferred to the gas molecules by a rapidly rotating bladed disc. 高真空（压力降至约10−8Pa）泵，其中动量通过快速旋转的叶片盘传递给气体分子。 |
| Transverse direction | 横向 |
Literally, the “across” direction, usually signifying a direction or plane perpendicular to the direction of working. In rolled plate or sheet, the direction across the width is often called long transverse, and the direction through the thickness, short transverse. 从字面上看，“横穿”方向，通常表示与工作方向垂直的方向或平面。在轧制钢板或薄板中，横跨宽度的方向通常称为长横向，穿过厚度的方向称为短横向。 |
| Stiffness | 刚度 |
(1) The ability of a metal or shape to resist elastic deflection.(2) The rate of stress increase with respect to the rate of increase in strain induced in the metal or shape; the greater the stress required to produce a given strain, the stiffer the material is said to be. （1）金属或形状抵抗弹性变形的能力。（2）所述应力增加速率相对于在所述金属或形状中诱导的应变增加速率；产生给定应变所需的应力越大，材料就越硬。 |
| Deposit gauge | 沉积量计 |
(deposition gauge) An instrument employed in air pollution studies for measuring the amount of pollutant deposited on a given area in a given time under given conditions. （沉降计）在空气污染研究中使用的仪器，用于测量在给定条件下在给定时间内沉积在给定区域上的污染物量。 |
| Low-E coating | 低辐射涂层 |
(low-emittance coating) A thin metallic or metal-oxide coating on a glass sheet to absorb and reflect infrared radiation. The coating is applied either by a pyrolytic chemical vapour-deposition process (hard coat), or by sputtering (soft coat). （低辐射涂层）玻璃板上的薄金属或金属氧化物涂层，用于吸收和反射红外辐射。通过热解化学气相沉积工艺（硬涂层）或溅射（软涂层）施加涂层。 |
| Engine emissions | 发动机排放 |
(exhaust emissions) The pollutants contained in the exhaust gases from an internal-combustion engine. （废气排放）内燃机废气中所含的污染物。 |
| Selective quenching | 局部淬火 |
Quenching only certain portions of an object. 仅淬火工件的某些部分。 |
| Air cleaner | 空气净化器 |
A device, such as a filter, hydrocyclone, or electrostatic precipitator, that removes particles and aerosols from a flow of air. 一种设备，例如过滤器、水力旋流器或静电除尘器，用于从气流中去除颗粒和气溶胶。 |
| Machine screw | 机械螺丝 |
A countersunk, slotted screw with machined threads such as are found on bolts. A relatively small screw, usually less than 20 mm in diameter, with the thread running along the whole length up to the head, intended to be screwed into threaded holes. If inserted through plain holes in assembled parts and held together by a nut, an undesirable contact surface of threads bearing against the surface of a hole results. 带有机加工螺纹的沉头开槽螺钉，如螺栓上的螺纹。一种相对较小的螺钉，直径通常小于20毫米，螺纹沿整个长度一直延伸到头部，用于拧入螺纹孔中。如果通过装配零件上的平孔插入并用螺母固定在一起，则会导致螺纹与孔表面接触不良。 |
| Solution heat treatment | 固溶热处理 |
Heating an alloy to a suitable temperature, holding at that temperature long enough to cause one or more constituents to enter into solid solution, and then cooling rapidly enough to hold these constituents in solution. 将合金加热到合适的温度，在该温度下保持足够长的时间以使一种或多种成分进入固溶体，然后快速冷却以将这些成分保持在溶液中。 |
| Frequency | 频率 |
(temporal frequency, f) (Unit Hz) The number of cycles per second in an oscillation or the repetition rate for a cyclic process. （时间频率，f）（单位Hz）振荡中每秒的周期数或循环过程的重复率。 |
| Ackerman linkage | 阿克曼装置 |
A steering linkage on a motor vehicle that approximately gives rolling without slipping of both wheels about the turning point. This is achieved by having the inner stub axle (on the inside of the turning curve) move through a greater angle than the outer stub axle. 机动车辆上的一种转向联动装置，在转向点附近两个车轮几乎不会打滑。这是通过使内短轴（在转弯曲线的内侧）比外短轴移动更大的角度来实现的。 |
| Toggle (toggle clamp) | 拨动（拨动夹） |
A device consisting of two pinned levers that are almost in line between two end points in the same plane. Bringing the levers into line generates large forces between the ends. Used to obtain a large mechanical advantage or as a locking mechanism. 由两个销杆组成的装置，在同一平面的两个端点之间几乎成一条直线。将杠杆对齐会在端部之间产生较大的力。用于获得较大的机械优势或用作锁定机构。 |
| Elastic interactions | 弹性相互作用 |
When a bolt is tightened it partially compresses the joint members ‘‘in its own neighborhood.’’ When nearby bolts are tightened later, they further compress the joint in this region. This allows the first bolt to relax a little (lose a little preload). Tightening bolts on the opposite side of the joint, however, might increase preload in some of the earlier bolts tightened on the near side. These shifts and changes in the elastic energy stored in individual bolts, during assembly, are called elastic interactions. 当螺栓拧紧时，它会“在其自身附近”部分压缩接头构件稍后拧紧附近的螺栓时，进一步压缩该区域的接头。这允许第一个螺栓稍微松弛（失去一点预载）。但拧紧接头另一侧的螺栓可能会增加早期在近侧拧紧的一些螺栓的预载。在装配过程中，储存在单个螺栓中的弹性能量的这些位移和变化称为弹性相互作用。 |
| Altitude | 高度 |
(Unit m) Vertical height measured relative to a specified datum such as sea level. （单位m）相对于特定基准（例如海平面）测量的垂直高度。 |
| Constant-force spring | 恒力弹簧 |
A spring that has the same restoring force regardless of displacement. The most common type takes the form of a coiled strip that, owing to tight coiling during manufacture, is pre-stressed (a steel measuring tape is an example). The uncoiling force is approximately constant as the change of curvature of the strip is approximately constant. Not to be confused with a clockwork spring from which power can be obtained. 无论位移如何，具有相同恢复力的弹簧。最常见的类型是卷绕带，由于制造过程中的紧密卷绕，该卷绕带是预应力的（钢卷尺就是一个例子）。随着带材曲率的变化近似恒定，开卷力近似恒定。不要与可获得动力的发条弹簧混淆。 |
| Hard temper | 硬化回火 |
Same as full hard temper. 和全硬化回火一样。 |
| Wind tunnel | 风洞 |
A duct in which a controlled flow of air is used for testing and research. Types include blow down, closed circuit, open return, and open section. Closed-circuit tunnels may be pressurized or evacuated. The working section is usually situated immediately downstream of the flow-conditioning elements, which may include a plenum chamber, honeycomb, screens, turbulence grids, and a contraction. Immediately downstream there is usually a diffuser. For basic research the usual requirement is for uniform steady flow in the working section with low swirl and turbulence intensity. For some applications the flow may be density stratified, sheared, unsteady, or of high turbulence intensity. 用于测试和研究的可控气流管道。类型包括排污、闭路、开路回路和开路段。闭路隧道可加压或排空。工作段通常位于流量调节元件的下游，可包括增压室、蜂窝、滤网、湍流格栅和收缩管。紧靠下游通常有一个扩散器。对于基础研究，通常的要求是在低涡流和湍流强度的工作段中实现均匀稳定流动。对于某些应用，流动可能是密度分层、剪切、不稳定或高湍流强度。 |
| Effective crack size (ae) | 有效裂纹尺寸（ae） |
The physical crack size augmented for the effects of cracking plastic deformation. Sometimes the effective crack size is calculated from a measured value of a physical crack size plus a calculated value of a plastic-zone adjustment. A preferred method for calculation of effective crack size compares compliance from the secant of a load-deflection trace with the elastic compliance from a calibration for the type of specimen. 由于裂纹塑性变形的影响，物理裂纹尺寸增大。有时，根据物理裂纹尺寸的测量值加上塑性区调整的计算值来计算有效裂纹尺寸。计算有效裂纹尺寸的首选方法是将载荷-挠度轨迹正割的柔度与试样类型校准的弹性柔度进行比较。 |
| Newton’s law of gravitation | 牛顿万有引力定律 |
(Newton’s law of universal gravitation) Any two bodies exert a gravitational force of attraction F on each other directed along the line joining their centres of mass, in magnitude proportional to the product of their masses and inversely proportional to the square of the distance r between them. （牛顿万有引力定律）任何两个物体沿其质心连接线相互施加引力F，其大小与其质量乘积成正比，与它们之间距离r的平方成反比。 |
| Turn-of-nut | 转动螺母 |
Sometimes used to describe the general rotation of the nut (or bolt head) as the fastener is tightened. More often used to define a particular tightening procedure in which a fastener is first tightened with a preselected torque, and is then tightened further by giving the nut an additional, measured, turn such as ‘‘three flats’’ (180°). 有时用于描述紧固件拧紧时螺母（或螺栓头）的总体旋转。更常用于定义一种特定的紧固程序，在该程序中，首先以预选扭矩拧紧紧固件，然后通过使螺母额外转动，如“三平面”（180°）进一步拧紧。 |
| ANSI | ANSI |
The acronym for American National Standards Institute. 美国国家标准协会的缩写。 |
| Morse taper | 莫氏锥度 |
A self holding, standard taper largely used on drilling tools, drilling machine spindles, and some lathes. 一种自持式标准锥度，主要用于钻孔工具、钻床主轴和一些车床。 |
| Gas compressor | 气体压缩机 |
A machine which draws in a gas at low pressure and delivers it at high pressure, usually accompanied by a temperature increase. Compressor designs include axial, centrifugal, diaphragm, reciprocating, and rotary (including the blade compressor). 一种在低压下吸入气体并在高压下输送气体的机器，通常伴随着温度升高。压缩机设计包括轴流式、离心式、隔膜式、往复式和旋转式（包括叶片式压缩机）。 |
| Bearing strain | 轴承应变 |
The ratio of the deformation of the bearing hole, in the direction of the applied force, to the pin diameter in a bearing test. 轴承孔在作用力方向上的变形与轴承测试中销直径的比值。 |
| Grain size | 晶粒大小 |
A measure of the areas or volumes of grains in a polycrystalline metal, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. For metals, a measure of the areas or volumes of grains in a polycrystalline material, usually expressed as an average when the individual sizes are fairly uniform. In metals containing two or more phases, the grain size refers to that of the matrix unless otherwise specified. Grain sizes are reported in terms of number of grains per unit area or volume, average diameter, or as a grainsize number derived from area measurements. 多晶金属中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。多晶材料中晶粒的面积或体积的量度，通常表示为单个尺寸相当均匀时的平均值。在含有两相或多相的金属中，除非另有说明，晶粒尺寸是指基体的晶粒尺寸。晶粒尺寸以每单位面积或体积的晶粒数、平均直径或从面积测量得出的晶粒尺寸数来报告。 |
| Working fluid | 工作流体 |
In thermodynamics, the fluid contained within the boundary of a system that experiences changes in its properties during any fluid dynamic or thermodynamic process. 在热力学中，包含在系统边界内的流体，在任何流体动力学或热力学过程中其性质发生变化。 |
| Springback | 回弹 |
The extent to which metal tends to return to its original shape or contour after undergoing a forming operation. 金属在经历成形操作后趋于恢复其原始形状或轮廓的程度。 |
| R-curve/Resistance curve | 阻力曲线 |
In linear-elastic fracture mechanics, a plot of crack-extension resistance as a function of stable crack extension, which is either the difference between the physical crack size, or the effective crack size, and the original crack size. R-curves normally depend on specimen thickness and, for some materials, on temperature and strain rate. An increase in fracture toughness with crack propagation shown by rising plots of toughness vs growing crack length. 在线弹性断裂力学中，作为稳定裂纹扩展函数的裂纹扩展阻力图，即物理裂纹尺寸或有效裂纹尺寸与原始裂纹尺寸之间的差值。R曲线通常取决于试样厚度，对于某些材料，还取决于温度和应变率。是随着裂纹扩展，断裂韧性增加，表现为韧性与扩展裂纹长度的上升曲线。 |
| Bright nitriding | 光亮氮化 |
Nitriding in a protective medium to prevent discoloration of the bright surface. 在保护介质中氮化，以防止光亮表面变色。 |
| Full hard | 全硬化 |
A temper of nonferrous alloys and some ferrous alloys corresponding approximately to a coldworked state beyond which the material can no longer be formed by bending. In specifications, a full hard temper is commonly defined in terms of minimum hardness or minimum tensile strength (or, alternatively, a range of hardness or strength) corresponding to a specific percentage of cold reduction following a full anneal. For aluminum, a full hard temper is equivalent to a reduction of 75% from dead soft ; for austenitic stainless steels, a reduction of about 50 to 55%. 有色金属合金和一些铁合金的回火状态，大致对应于冷加工状态，超过该状态，材料就不能再通过弯曲形成。在规范中，完全硬质回火通常定义为与完全退火后的特定冷压下率百分比相对应的最小硬度或最小抗拉强度（或者，硬度或强度范围）。对于铝来说，完全硬回火相当于从极软状态减少75%；对于奥氏体不锈钢，减少约50%至55%。 |
| Diaphragm compressor | 隔膜式压缩机 |
A machine in which compression is achieved by the reciprocating motion of a flexible membrane of metal, plastic, or elastomeric material. This arrangement is ideally suited to pumping high-purity, toxic, or explosive gases. A similar machine incorporating check valves is a self-priming positive-displacement pump (diaphragm pump, membrane pump). 通过金属、塑料或弹性材料的柔性薄膜的往复运动实现压缩的机器。这种布置非常适合泵送高纯度、有毒或爆炸性气体。装有止回阀的类似机器是自吸容积泵（隔膜泵、隔膜泵）。 |
| Elbow | 肘部 |
1. A fitting that connects the ends of two pipes at an angle, 45°, 90°, and 180° being the most common. 2. The third joint on an articulated robot corresponding to the human elbow. 1.以45°、90°和180°角连接两个管道端部的配件。2.示例关节机器人上的第三关节对应于人的肘部。 |
| Flange rotation | 法兰转角 |
Angular distortion of a flange under the influence of bolt and reaction forces. Measured with respect to the center of the cross section of the flange. 法兰在螺栓和反作用力影响下的角度变形。相对于法兰横截面的中心测量。 |
| Decompression chamber | 减压舱 |
A chamber in which ambient-air pressure can be increased to levels found in deep-sea diving. It is used to gradually acclimatize divers back to normal conditions and avoid ‘the bends’. 环境气压可以提高到深海潜水水平的腔室。它用于逐渐使潜水员适应正常条件，避免“弯曲”。 |
| Critical compression ratio | 临界压缩比 |
1. The compression ratio for incipient knock of hydrocarbon fuels as determined in a variable-compression single-cylinder piston engine. 2. The compression ratio at which an air–fuel mixture will spontaneously ignite due to the temperature increase produced. 1.在可变压缩单缸活塞发动机中确定的烃类燃料初期爆震的压缩比。2.空气-燃料混合物由于产生的温度升高而自燃的压缩比。 |
| Maximum material condition | 最大材料条件 |
(maximum metal condition) The situation where the volume of a manufactured component corresponds to the upper limit for all toleranced external dimensions, and to the lower limit for all internal dimensions. （最大金属条件）制造部件的体积对应于所有公差外部尺寸的上限和所有内部尺寸的下限的情况。 |
| Eutectic | 共晶 |
(1) An isothermal reversible reaction in which a liquid solution is converted into two or more intimately mixed solids on cooling, the number of solids formed being the same as the number of components in the system. (2) An alloy having the composition indicated by the eutectic point on an equilibrium diagram. (3) An alloy structure of intermixed solid constituents formed by a eutectic reaction. （1）一种等温可逆反应，其中液体溶液在冷却时转化为两种或两种以上紧密混合的固体，形成的固体数量与系统中组分的数量相同。（2）一种合金，其成分由平衡图上的共晶点表示。（3）由共晶反应形成的混合固体成分的合金结构。 |
| Water column | 水柱 |
Water in a tube, which may be vertical or inclined. If the tube is open to the atmosphere, the vertical height h from a datum level to the water surface is a measure of the water static pressure p at the datum level given by p − B = ρgh where B is the barometric pressure, ρ denotes the water density, and g is the acceleration due to gravity. 管道中的水，可以是垂直的或倾斜的。如果管道向大气开放，则从基准面到水面的垂直高度h是基准面处水静压p的量度，由p给出−B=ρgh，其中B是大气压力，ρ表示水密度，g是重力引起的加速度。 |
| Vibrograph | 示振器 |
An instrument that records vibrations in a system over time. 记录系统随时间变化的振动的仪器。 |
| Biaxial stress | 双轴应力 |
Generalized loading of a body in a single plane with no loading normal to it. 物体在一个平面内的广义载荷，没有垂直于它的载荷。 |
| Rockwell hardness number (HR) | 洛氏硬度值（HR） |
A number derived from the net increase in the depth of impression in a Rockwell hardness test as the load on an indenter is increased from a fixed minor load to a major load and then returned to the minor load. Rockwell hardness numbers are always quoted with a scale symbol representing the penetrator, load, and dial used. 当压头上的载荷从固定的小载荷增加到大载荷，然后返回到小载荷时，洛氏硬度试验中压痕深度的净增加值。洛氏硬度值总是用刻度符号引用，表示所用的穿透器、载荷和刻度盘。 |
| Diagonal pitch (Unit m) | 对角线间距（单位米） |
The distance, when components in an assembly are staggered, between the position of a component in one row or column and the position of the corresponding component in the next row or column. The term is applied to rivets, turbine or compressor blades in a cascade, vortex generators on the surface of a wing, etc. 当部件中的零部件交错时，一行或一列中零部件的位置与下一行或下一列中相应零部件的位置之间的距离。该术语适用于铆钉、叶栅中的涡轮或压缩机叶片、机翼表面的涡流发生器等。 |
| Swift cup test | 斯威夫特杯测试 |
A simulative cupping test in which circular blanks of various diameters are clamped in a die ring and deep drawn into cups by a flat-bottomed cylindrical punch. 一种模拟拔杯试验，将不同直径的圆形坯料夹紧在模环中，并用平底圆柱冲头将其深拉入杯中。 |
| Rated flow (Unit m³/s or kg/s) | 额定流量（单位：m³/s或kg/s） |
In a hydraulic system or machine, the volume or mass flow rate a manufacturer specifies for a component as the maximum desirable for it to function as designed. 在液压系统或机器中，制造商为部件指定的体积或质量流量是其按设计运行所需的最大值。 |
| Rubber hardness | 橡胶硬度 |
The indentation hardness of rubber-like materials in which the depth of indentation under load is measured. This is a measure of elastic moduli rather than yield stress as with ductile materials, since there is little, if any, permanent impression remaining on unloading rubbery materials. 测量负载下压痕深度的橡胶类材料的压痕硬度。这是对弹性模量的测量，而不是对韧性材料的屈服应力，因为卸载橡胶材料时几乎没有（如果有的话）永久压痕。 |
| Pascal (Pa) | 帕斯卡（Pa） |
The SI unit of pressure, 1 Pa = 1 N/m². 压力的国际单位制，1Pa=1N/m²。 |
| Stress relieving | 应力消除 |
Heating to a suitable temperature, holding long enough to reduce residual stresses, and then cooling slowly enough to minimize the development of new residual stresses. 加热到合适的温度，保持足够长的时间以减少残余应力，然后缓慢冷却以尽量减少新残余应力的产生。 |
| Clevis joint | U形接头 |
A joint formed by two parallel cantilever beams pressed upon a component between the beams. 由两个平行悬臂梁压在梁之间的部件上形成的接头。 |
| Centrifuge | 离心机 |
A machine incorporating a rapidly spinning drum in which liquids and suspended particles of different densities are separated by centrifugal action. 一种装有快速旋转滚筒的机器，在该滚筒中，不同密度的液体和悬浮颗粒通过离心作用分离。 |
| Anelastic | 无弹性 |
Literally ‘not elastic’, but in practice used for materials that display timedependent recovery on unloading. 字面意思是“没有弹性”，但实际上用于在卸载时显示随时间恢复的材料。 |
| International System of Units | 国际单位制 |
(SI system of units, Le Système international d’unités) The standard system of units now used almost universally in science and engineering except in the United States. The definitive reference on the SI is a booklet published by the International Bureau of Weights and Measures, often referred to as the BIPM SI Brochure. There are seven base units: metre (symbol m) for length; kilogram (kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred.(kg) for mass; mole (mol) for amount of substance; second (s) for time; kelvin (K) for temperature; ampere (A) for electric current; and candela (cd) for luminous intensity. New SI unit definitions, based upon the values of the universal constants of nature (also termed the fundamental physical constants: the Avogadro constant, the Boltzmann constant, and the Planck constant), came into effect on 20 May 2019. Minor adjustments were also made to the values of these constants. In addition to the base units, there are 22 coherent derived units, including radian (rad) for plane angle, steradian (sr) for solid angle, hertz (Hz) for frequency, newton (N) for force, pascal (Pa) for pressure, joule (J) for energy, work, and amount of heat, and watt (W) for power and radiant flux. Recommended practice is to avoid combinations such as N/mm², MN/m² being preferred. （国际单位制，Le Système international d\\\'unités）目前美国除外，在科学和工程中几乎是普遍使用的标准单位制。SI的最终参考是国际度量衡局出版的小册子，通常称为BIPM SI小册子。有七个基本单位：米（符号m）表示长度；质量为千克（kg）；物质量的摩尔（mol）；时间为秒；开尔文（K）表示温度；电流为安培（A）；而坎德拉（cd）表示发光强度。新的国际单位制定义于2019年5月20日生效，该定义基于自然界的普遍常数（也称为基本物理常数：阿伏伽德罗常数、玻尔兹曼常数和普朗克常数）。这些常数的值也进行了少量调整。除了基本单位外，还有22个相干导出单位，包括平面角的弧度（rad）、立体角的斯特拉迪安（sr）、频率的赫兹（Hz）、力的牛顿（N）、压力的帕斯卡（Pa）、能量、功和热量的焦耳（J）以及功率和辐射通量的瓦特（W）。建议的做法是避免N/mm²、MN/m²等组合。 |
| Total elongation | 总伸长率 |
A total amount of permanent extension of a test piece broken in a tensile test. 拉伸试验中断裂试样的永久延伸总量。 |
| Atomization | 雾化 |
The production of a spray of fine droplets from a liquid, such as diesel oil or petrol, by injection through a nozzle (an atomizer). 通过喷嘴（雾化器）喷射从液体（例如柴油或汽油）中产生细小液滴喷雾。 |
| Stress corrosion cracking (SCC) | 应力腐蚀开裂（SCC） |
A common form of Stress cracking in which an Electrolyte encourages the growth of a crack in a highly stressed bolt. Only a tiny quantity of electrolyte need be present, at the tip or face of the crack. A time-dependent process in which a metallurgically susceptible material fractures prematurely under conditions of simultaneous corrosion and sustained loading at lower stress levels than would be required in the absence of a corrosive environment. Tensile stress is required at the metal surface and may be a residual stress resulting from heat treatment or fabrication of the metal or the result of external loading. Cracking may be intergranular or transgranular, depending on the combination of alloy and environment. 一种常见的应力开裂形式，其中电解液促使高应力螺栓中的裂纹扩展。在裂纹尖端或表面，只需存在少量电解质。一种随时间变化的过程，其中冶金敏感材料在同时腐蚀和持续加载的条件下过早断裂，其应力水平低于无腐蚀环境时的要求。在金属表面需要拉应力，拉应力可以是金属的热处理或制造或外部负载产生的残余应力。裂纹可能是沿晶开裂或穿晶开裂，这取决于合金和环境的组合。 |
| Spring load (Unit N) | 弹簧载荷（单位：N） |
A load exerted on a component by bending, compressing, extending, or twisting an attached spring. Mechanical energy stored in the spring can be released if any constraints on the component are removed. 通过弯曲、压缩、延伸或扭转连接的弹簧而施加在部件上的载荷。如果部件上的任何约束被移除，则可以释放弹簧中存储的机械能。 |
| Damage mechanics | 损伤机制 |
The theory of degradation in bodies, particularly fracture by accumulated microstructural damage. Analyses take two approaches: (a) the use of some critical integrated function of stress and strain at which cracking is initiated and propagated; (b) incorporation of damage in the stress–strain curves to reflect weakened material. 物体退化理论，尤其是累积微观结构损伤导致的断裂。分析采用两种方法：（a）使用裂纹开始和扩展时的应力和应变的一些临界积分函数；（b）应力-应变曲线中包含损伤，以反映弱化材料。 |
| Half hard | 半硬化回火 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength about mid-way between that of dead soft and full hard tempers. 非铁合金和某些铁合金的一种回火，其特点是抗拉强度介于完全软回火和完全硬回火之间。 |
| Biomedical engineering | 生物医学工程 |
The application of engineering principles and methodology to the medical field. Examples involving mechanical engineering include the design and construction of artificial limbs and hearts, heart-lung machines, prosthetic eyes, and orthopaedic implants such as hip joints and pins to stabilize fractured bones. 工程原理和方法在医学领域的应用。涉及机械工程的例子包括假肢和心脏、心肺机、假眼和骨科植入物（如髋关节和用于稳定骨折骨骼的销钉）的设计和建造。 |
| Structure | 结构体 |
An assembly, usually load bearing, of connected (pinned, riveted, screwed, bolted, welded, etc.) components, such as bars, tubes, beams, and plates. 由连接（销接、铆接、螺纹连接、螺栓连接、焊接等）部件组成的组件，通常为承重组件，如杆、管、梁和板。 |
| Plane stress | 平面应力 |
The stress condition in linear-elastic fracture mechanics in which the stress in the thickness direction is zero; most nearly achieved in loading very thin sheet along a direction parallel to the surface of the sheet. Under plane-stress conditions, the plane of fracture instability is inclined 45° to the axis of the principal tensile stress. 线弹性断裂力学中厚度方向上的应力为零的应力条件；在沿着平行于薄片表面的方向加载非常薄的薄片时最接近。在平面应力条件下，断裂失稳平面与主拉应力轴倾斜45°。 |
| Effective length of a bolt | 螺栓的有效长度 |
The grip length plus some portion of the bolt (often one-half of the thickness of the nuts) which lies within the nut(s) plus some portion (often one-half the thickness) of the head. 握持长度加上位于螺母内的螺栓的某些部分（通常是螺母厚度的二分之一）加上头部的某些部分（通常是厚度的二分之一）。 |
| Thermoelectric converter | 热电转换器 |
(thermoelectric generator) A device consisting of series-connected alternate n- and p-type semiconductor elements sandwiched between two ceramic plates. Due to the Seebeck effect, electrical power is generated when a temperature difference is maintained across the plates. Due to the Peltier effect, a thermoelectric converter can act as either a thermoelectric heater or a thermoelectric cooler (thermoelectric refrigerator) by passing an electrical current through it. The thermoelectric figure of merit (Z), with unit 1/K, is a dimensional parameter on which the efficiency of a thermoelectric device is primarily dependent, defined by Z = σα2/k where α is the Seebeck coefficient, σ is the electrical conductivity, and k is the thermal conductivity. The product of Z and a temperature is non-dimensional. （热电发生器）由串联连接的交替的n型和p型半导体元件夹在两块陶瓷板之间组成的装置。由于塞贝克效应，当板之间保持温差时，就会产生电能。由于珀尔帖效应，热电转换器可以通过使电流通过而充当热电加热器或热电冷却器（热电制冷机）。热电优值（Z）和第一单元/K是一个尺寸参数，热电装置的效率主要取决于此，由Z=σα2/K定义，其中α是塞贝克系数，σ是电导率，K是热导率。Z和温度的乘积是无量纲的。 |
| Transducer | 传感器 |
A device which converts one form of energy into another. An ultrasonic transducer, for example, converts electrical energy into acoustic energy (at ultrasonic frequencies) and vice versa. 将一种形式的能量转换为另一种形式能量的装置。例如，超声换能器将电能转换为声能（在超声频率下），反之亦然。 |
| Fluid mechanics | 流体力学 |
The study of fluids in motion (fluid dynamics) or fluid statics where there is no relative motion between fluid particles. Fluid statics concerns primarily the variation of pressure with altitude or depth; it includes aerostatics and hydrostatics. Fluid dynamics includes the topics of aerodynamics, gas dynamics, hydraulics, hydrodynamics and many aspects of acoustics, chemical engineering, flight, lubrication, meteorology, non-Newtonian fluid flow, oceanography, power-plant technology, propulsion, and turbomachinery. 研究运动中的流体（流体动力学）或流体静力学，其中流体粒子之间没有相对运动。流体静力学主要关注压力随高度或深度的变化；它包括空气静力学和流体静力学。流体动力学包括空气动力学、气体动力学、水力学、流体动力学以及声学、化学工程、飞行、润滑、气象学、非牛顿流体流动、海洋学、发电厂技术、推进和涡轮机械的许多方面。 |
| Tow | 拖拉 |
1. To cause a vehicle to move by pulling with a rope, chain, bar, etc. 2. A bundle of fibres employed in reinforcement. 1.用绳子、链条、钢筋等拉动车辆移动。2.用于加固的纤维束。 |
| Circular pitch | 齿距 |
The distance from the center of one gear tooth to the center of the next gear tooth measured on the pitch line. 在节线上测量的从一个轮齿中心到下一个轮齿中心的距离。 |
| Compressor | 压缩机 |
A turbomachine, of either axial or radial type, that increases the pressure of a gas or vapour. 一种增加气体或蒸汽压力的轴向或径向涡轮机。 |
| Fracture mechanisms | 断裂机制 |
The microstructural mechanisms that cause fracture, such as void initiation, growth and coalescence, cleavage. 导致断裂的微观结构机制，如空隙的萌生、生长和聚结、解理。 |
| Austempering | 等温淬火 |
A heat treatment for ferrous alloys in which a part is quenched from the austenitizing temperature at a rate fast enough to avoid formation of ferrite or pearlite and then held at a temperature just above Ms until transformation to bainite is complete. Although designated as bainite in both austempered steel and austempered ductile iron (ADI), austempered steel consists of two phase mixtures containing ferrite and carbide, while austempered ductile iron consists of two phase mixtures containing ferrite and austenite. Heat treatment comprising austenitization of a steel article, cooling it to a bainitic range at a rate higher than the critical cooling rate and holding at a fixed temperature until the completion of bainitic transformation. 一种铁合金的热处理，其中零件从奥氏体化温度以足够快的速度淬火，以避免形成铁素体或珠光体，然后保持在略高于Ms的温度，直到完全转变为贝氏体。虽然在奥氏体钢和奥氏体球铁(ADI)中都被指定为贝氏体，但奥氏体钢由含有铁素体和碳化物的两相混合物组成，而奥氏体球墨铸铁由含有铁素体和奥氏体的两相混合物组成。热处理包括钢制品的奥氏体化，以高于临界冷却速率的速率将其冷却到贝氏体范围，并保持在固定温度直到贝氏体转变完成。 |
| Allowable stress design | 许用应力设计 |
A design procedure developed for the AISC by the Research Council on Structural Connections. Purposely underestimates the strengths of bolts and joint materials to introduce safety factors into the design of structural steel joints. It is an alternative to the more recently defined load and resistance factor design procedure. 结构连接研究委员会为AISC制定的设计程序。故意低估螺栓和接头材料的强度，以便在结构钢接头的设计中引入安全系数。它是最近定义的荷载和阻力系数设计程序的替代方法。 |
| Spanner (wrench) | 扳手 |
A tool for applying torque to tighten or loosen a nut, bolt, or screw. Grip is applied by a serrated ring or an open U-shape at the end of the tool. On imperial-size spanners, the BSW and BSF marking refers to the diameter of the screw thread; similarly for BA spanners. Spanners for unified and metric threads are marked with the distance across the flats (‘A/F’) of the nut or head of the bolt. 拧紧或松开螺母、螺栓或螺丝的工具。通过工具端部的锯齿环或开口U形应用夹持。在英制扳手上，BSW和BSF标记是指螺纹的直径；类似于BA扳手。用于统一螺纹和公制螺纹的扳手在螺母或螺栓头的平面（'A/F'）上标记距离。 |
| Load factor (F) | 负载系数（F） |
The ratio between an increase in bolt tension and the external load which has caused the increase. Factors reflecting the probability of an increase in load in a shear joint. Used in load and resistant factor design. 螺栓张力增加与导致增加的外部载荷之间的比率。反映剪切接缝中荷载增加概率的系数。用于载荷和阻力系数设计。 |
| Car furnace | 车炉 |
A batch-type furnace using a car on rails to enter and leave the furnace area. Car furnaces are used for lower stress relieving ranges. 一种间歇式炉，使用轨道上的小车进出炉区。汽车炉用于较低的应力消除范围。 |
| Zero initial conditions | 零初始条件 |
The assumption normally made in control engineering that up to a start time defined as t = 0, all variables have zero value. 在控制工程中通常作出的假设，即在定义为t=0的开始时间内，所有变量均为零值。 |
| Silky fracture | 丝状断口 |
A metal fracture in which the broken metal surface has a fine texture, usually dull in appearance. Characteristic of tough and strong metals. 一种金属断裂，断裂的金属表面具有精细的纹理，通常外观暗淡。具有坚韧和坚固金属的特征。 |
| Hardness | 硬度 |
A measure of the resistance of a material to surface indentation or abrasion; may be thought of as a function of the stress required to produce some specified type of surface deformation. There is no absolute scale for hardness; therefore, to express hardness quantitatively, each type of test has its own scale of arbitrarily defined hardness. Indentation hardness can be measured by Brinell hardness test, Rockwell hardness test, Vickers hardness test, Knoop hardness test, and the Scleroscope hardness test. The ability of a ductile material to resist permanent deformation. It is a measure of plastic flow properties determined principally by indentation testing, but scratch hardness and rebound hardness are also employed. hardness scales The different measures of hardness given by different tests, such as indentation pressure in the Brinell and in the Vickers hardness tests, and the different Rockwell hardness numbers. 测量材料对表面压痕或磨损的阻力；可以认为是产生某些特定类型的表面变形所需的应力的函数。硬度没有绝对刻度，因此为了定量表示硬度，每种类型的试验都有自己的任意定义硬度等级。压痕硬度可通过布氏硬度试验、洛氏硬度试验，维氏硬度试验和努氏硬度试验以及硬化镜硬度试验进行测量。延展性材料具有抵抗永久变形的能力，它是主要通过压痕测试确定的塑性流动性能的量度，也使用划痕硬度和回弹硬度。硬度标度不同试验给出的不同硬度测量值，如布氏硬度试验和维氏硬度试验中的压痕压力，以及不同的洛氏硬度值。 |
| Thermodynamic properties | 热力学性质 |
Temperature, pressure, and the intensive properties that define the state of a working fluid: specific internal energy, specific enthalpy and specific entropy. 温度、压力和定义工作流体状态的密集属性：比内能、比焓和比熵。 |
| Failure | 失效 |
The result when a body, component, or structure is incapable of performing the task for which it was designed. The term is often used without reference to what causes failure, such as fracture, buckling, excessive deformation, wear, or erosion. Failure criteria (failure theories, theories of strength) are mathematical expressions for the combinations of stress, strain, or strain energy at which materials fail, which are employed in design to dimension components. 主体、部件或结构无法执行其设计任务时的结果。该术语通常未提及导致失效的原因，如断裂、屈曲、过度变形、磨损或侵蚀。失效准则（失效理论、强度理论）是材料失效时应力、应变或应变能组合的数学表达式，用于部件尺寸设计。 |
| Surface hardening | 表面硬化 |
A generic term covering several processes applicable to a suitable ferrous alloy that produces, by quench hardening only, a surface layer that is harder or more wear resistant than the core. There is no significant alteration of the chemical composition of the surface layer. The processes commonly used are carbonitriding, carburizing, induction hardening, flame hardening, nitriding, and nitrocarburizing. Use of the applicable specific process name is preferred. 一个通用术语，涵盖适用于仅通过淬火硬化产生比型芯更硬或更耐磨的表面层的合适铁合金的几种工艺。表面层的化学成分没有显著改变。常用的工艺有碳氮共渗、渗碳、感应淬火、火焰淬火、氮化和氮碳共渗。最好使用适用的特定工艺名称。 |
| Diaphragm meter | 隔膜计 |
A dry flow meter in which there are two or more interconnected chambers, each having a diaphragm in the wall. The chambers empty and fill alternately and the flow rate of gas is determined from the movement of diaphragms. Diaphragm meters are commonly used to monitor domestic and commercial gas supply. 一种干式流量计，其中有两个或多个相互连接的腔室，每个腔室的壁上都有一个隔膜。腔室交替排空和填充，气体流速由隔膜的移动确定。隔膜流量计通常用于监测家用和商用燃气供应。 |
| Celsius temperature scale | 摄氏温标 |
(centigrade temperature scale) A relative, non-SI, temperature scale now defined in terms of the Kelvin absolute temperature scale as °C = K − 273.15, where °C is the symbol for degrees Celsius. The scale was previously called the centigrade scale, with two fixed points: the melting point of ice (the ice point) as 0°C, and the boiling point of water (the steam point) as 100°C. （摄氏度温度标度）现在以开尔文绝对温度标度定义的相对非国际温度标度为°C=K-273.15，其中°C是摄氏度的符号。该刻度以前称为摄氏度刻度，有两个固定点：冰的熔点（冰点）为0°C，水的沸点（蒸汽点）为100°C。 |
| Surface roughness (roughness) | 表面粗糙度 |
The small-scale, irregular peaks and troughs in a solid surface which are quantified using a surface analyser. Roughness may be a consequence of wear and corrosion, or of the manufacturing process. It leads to increased friction in solid– solid contact or fluid flow over a surface. Errors of form and waviness are excluded, but surface texture includes roughness and waviness. Surface topography incorporates the small-scale, three-dimensional geometry of a surface including surface roughness, machined, and etched features, typically at sub-mm scales. 固体表面中的小尺度不规则峰谷，使用表面分析仪进行量化。粗糙度可能是磨损和腐蚀或制造过程的结果。它会导致表面上的固-固接触或流体流动中的摩擦增加。不包括形状和波纹度误差，但表面纹理包括粗糙度和波纹度。表面形貌包括表面的小尺度三维几何结构，包括表面粗糙度、机加工和蚀刻特征，通常为亚毫米尺度。 |
| Working stress (Unit Pa) | 工作应力（单位Pa） |
The stress under which a component or structure is designed to operate under normal conditions. 部件或结构设计为在正常条件下运行的应力。 |
| Bolt length | 螺栓长度 |
The bolt length shall be the distance measured parallel to the axis of the product from the bearing surface of the head to the extreme end of the bolt including point. 螺栓长度应为平行于产品轴线测量的从头部的支承面到包括点在内的螺栓末端的距离。 |
| Creep–time relations | 蠕变时间关系 |
Algebraic or numerical relations between creep strain and time at constant stress. 恒定应力下蠕变应变与时间之间的代数或数值关系。 |
| Destructive testing | 破坏性测试 |
Measurement of the mechanical properties of a material, component, or structure, by increased loading until the sample fails by fracture, collapse, or buckling. 通过增加载荷测量材料、部件或结构的机械性能，直到样品因断裂、塌陷或屈曲而失效。 |
| Beta annealing | β退火 |
Producing a beta phase by heating certain titanium alloys in the temperature range of which this phase forms followed by cooling at an appropriate rate to prevent its decomposition. 通过在形成β相的温度范围内加热某些钛合金，然后以适当的速率冷却以防止其分解，从而产生β相。 |
| Scatter | 分散 |
Data points or calculations are said to be scattered when they are not all the same. A ‘‘lot of scatter in preload’’ means wide variation in the preloads found in individual bolts. 当数据点或计算不尽相同时，它们被称为分散的。“预载的大量分散”意味着单个螺栓中的预载差异很大。 |
| Bearing stress | 承受应力 |
The force per unit of bearing area. 每单位承载面积的力。 |
| Brittle lacquer coating | 脆性漆涂层 |
A lacquer that, when painted on to an unloaded body, reveals the direction of maximum tension stresses from the pattern of cracking produced in the lacquer when the body is loaded. 一种漆，当涂在未加载的车身上时，从车身加载时在漆中产生的裂纹图案中显示出最大拉应力的方向。 |
| Shore hardness | 肖氏硬度 |
A measure of the hardness of materials such as elastomers, plastics, and rubbers determined using a Shore durometer which measures the penetration depth of a hardened steel rod (the indenter) 1.1–1.4 mm in diameter into the test material for a given force applied rapidly with a calibrated spring. There are two main indenter designs: type A (for softer materials) for which the end of the rod is a truncated 35° cone tapering to a diameter of 0.79 mm, and type D (harder materials) for which the end is a 30° cone with a 0.1 mm radius tip. The spring force is 8.05 N for type A and 44.45 N for type D. The hardness value is related to the penetration depth (limited to a maximum of 2.5 mm) such that for zero penetration the hardness is 100 and for maximum penetration the hardness is zero. The relevant standards are ISO 48-1, 48-4, and 48-7. Shore hardness values of selected materials are as follows: ABS 100, cellulose acetate 50–95, high-density polyethylene 60–70, low density polyethylene 40–50, polymethylmethacrylate 90–99, PTFE 50–65, and plasticized PVC 15–70. 使用肖氏硬度计测量弹性体、塑料和橡胶等材料的硬度，肖氏硬度仪测量直径为1.1–1.4mm的硬化钢棒（压头）在用校准弹簧快速施加的给定力下渗入试验材料的深度。有两种主要的压头设计：A型（适用于较软的材料），其杆端为截头35°锥形，逐渐变细至直径0.79 mm；D型（较硬的材料），端部为30°锥形，尖端半径为0.1mm。A型的弹簧力为8.05N，D型为44.45N。硬度值与渗透深度相关（最大限制为2.5mm），因此，对于零渗透，硬度为100，对于最大渗透，硬度是零。相关标准为ISO 48-1、48-4和48-7。所选材料的肖氏硬度值如下：ABS100、醋酸纤维素50-95、高密度聚乙烯60-70、低密度聚乙烯40-50、聚甲基丙烯酸甲酯90-99、PTFE50-65和塑化PVC15-70。 |
| Variance | 方差 |
A measure of the squared dispersion of observed values or measurements expressed as a function of the sum of the squared deviations from the population mean or sample average. 观测值或测量值的平方离散度的度量，表示为总体平均值或样本平均值的平方偏差之和的函数。 |
| Hardness profile | 硬度分布 |
Hardness as a function of distance from a fixed reference point (usually from the surface). 硬度作为距固定参考点（通常距表面）的距离的函数。 |
| Pressure (p) (Unit Pa) | 压力（p）（单位Pa） |
In thermodynamics and fluid mechanics, the compressive force exerted by the fluid per unit area. The pressure exerted by a fluid on a surface acts normal to the surface. 在热力学和流体力学中，每单位面积流体施加的压缩力。流体施加在表面上的压力垂直于表面。 |
| Critical point | 临界点 |
(1) The temperature or pressure at which a change in crystal structure, phase or physical properties occurs. Same as transformation temperature. (2) In an equilibrium diagram, that specific value of composition, temperature and pressure, or combinations thereof, at which the phases of a heterogeneous system are in equilibrium. （1） 晶体结构、相或物理性质发生变化的温度或压力。与转变温度相同。（2） 在平衡图中，指组成、温度和压力或其组合的特定值，在该值下，多相体系的相处于平衡状态。 |
| Rated power (Unit kW or hp) | 额定功率（单位：千瓦或马力） |
(rated capacity, rated horsepower) The maximum power output that can be sustained continuously for any power-producing machine or system, such as an engine or a power plant. （额定容量、额定马力）任何发电机器或系统（如发动机或发电厂）可连续维持的最大功率输出。 |
| Angularity | 角度 |
The underfaces of the nut and the bolt head should be exactly perpendicular to the thread or shank axes. If the angle between the face and the axis is, for example, 868 or 948, the fastener is said to have an angularity of 48 (sometimes called Perpendicularity). 螺母和螺栓头的底面应与螺纹或柄轴完全垂直。例如，如果面和轴之间的角度为868或948，则称紧固件的角度为48（有时称为垂直度）。 |
| Hardening | 硬化 |
Increasing hardness by suitable treatment, usually involving heating and cooling. When applicable, the following more specific terms should be used: age hardening, flame hardening, induction hardening, laser hardening, precipitation hardening, and quench hardening. 通过适当的处理增加硬度，通常包括加热和冷却。适用时，应使用以下更具体的术语：时效硬化、火焰硬化、感应硬化、激光硬化、沉淀硬化和淬火硬化。 |
| Modulus of elasticity (E) | 弹性模量（E） |
The measure of rigidity or stiffness of a metal; the ratio of stress, below the proportional limit, to the corresponding strain. In terms of the stress-strain diagram, the modulus of elasticity is the slope of the stress-strain curve in the range of linear proportionality of stress to strain. 金属的刚度或刚度的量度；低于比例极限的应力与相应应变之比。根据应力应变图，弹性模量是应力应变曲线在应力应变线性比例范围内的斜率。 |
| Vapour–pressure curve | 蒸汽压力曲线 |
For a pure substance, the curve of saturation pressure plotted vs saturation temperature. 对于纯物质，绘制了饱和压力与饱和温度的曲线。 |
| Thread rolling | 滚丝 |
Thread rolling (also known as roll threading) is a cold forming process for producing threads or other helical or annular forms by rolling the impression of hardened steel dies into the surface of a cylindrical or conical blank. Polygonal blanks are also thread rolled for the purpose of fabricating thread-forming and self-locking screws. The preferred polygonal shape is trilobular and is produced in flat die machines. 螺纹滚压（也称为滚压螺纹）是一种冷成型工艺，通过将硬化钢模具的压痕滚压到圆柱形或锥形坯料的表面来生产螺纹或其他螺旋或环形形状。多边形坯料也进行螺纹轧制，以制造螺纹成型和自锁螺钉。优选的多边形形状为三棱形，并在平模机中生产。 |
| Right hand thread | 右旋螺纹 |
A screw thread which advances into the mating part when turned clockwise or to the right. 顺时针或向右转动时进入配合部件的螺纹。 |
| Screw machine | 螺丝机 |
A machine tool for high-volume manufacture of small turned components from rod or bar. 一种用棒或棒大批量制造小零件的机床。 |
| Shoulder | 轴肩 |
The portion of a shaft, stepped component, or flanged component, where a change in diameter or other dimension occurs. Even for a nominal step change, in practice there will be a radius where shoulder and shaft meet in order to avoid too severe a stress concentration. 轴、阶梯部件或法兰部件的直径或其他尺寸发生变化的部分。即使是名义阶跃变化，在实践中，肩部和轴相交处也会有一个半径，以避免出现过严重的应力集中。 |
| Ferritic decarburization | 铁素体脱碳 |
Decarburization with sufficient loss of carbon to cause a lighter shade of tempered martensite and a significantly lower hardness than that of the adjacent base metal, with the presence of ferrite grains or grain boundary network under metallographic examination. 脱碳，碳损失充分，导致回火马氏体颜色较浅，硬度明显低于相邻母材，金相检查时存在铁素体晶粒或晶界网络。 |
| Mechanical metallurgy | 机械冶金 |
The science and technology dealing with the behavior of metals when subjected to applied forces. 处理金属在外力作用下的行为的科学技术。 |
| Combined heat and power plant | 热电联产电厂 |
(CHP plant, COGEN, cogeneration plant, total-energy plant) A plant for the simultaneous production of more than one useful form of energy from the same energy source, such as process heat and electric power. In the arrangement shown, partially expanded steam is extracted from the steam turbine and used to produce process heat. （CHP工厂、COGEN、热电联产工厂、总能源工厂）从同一能源（如过程热能和电力）同时生产一种以上有用能源的工厂。在所示的布置中，部分膨胀的蒸汽从蒸汽轮机中提取并用于产生过程热量。 |
| Weight (W) (Unit N) | 重量（W）（单位：N） |
The force of attraction on a body due to gravity. A body’s weight is the product of its mass and the gravitational field strength at that point. Mass remains constant, but weight depends on the object’s position on the Earth’s surface, decreasing with increasing altitude. If g is the acceleration due to gravity, the weight of a mass m is given by W = mg. On Earth, the acceleration due to gravity is approximately 9.81 m/s², so that the weight of a 1 kg mass is 9.81 N. More generally, the weight is the force exerted on the mass of a body when in the gravitational field of another body. 重力由于重力作用在物体上的吸引力。物体的重量是其质量和该点引力场强度的乘积。质量保持不变，但重量取决于物体在地球表面的位置，随着海拔的升高而减小。如果g是重力引起的加速度，则质量m的重量由W=mg给出。在地球上，重力引起的加速度约为9.81m/s²，因此1千克质量的重量为9.81N。更一般地说，重量是在另一个物体的重力场中施加在物体质量上的力。 |
| Aging treatment | 时效处理 |
Heat treatment aimed at age hardening; it comprises solution and precipitation treatments. 针对时效硬化的热处理；它包括溶液和沉淀处理。 |
| Static equilibrium | 静态平衡 |
A solid body, structure, or physical system (or any subdivided part) will be in static equilibrium, either at rest or moving with constant velocity, if the resultants of all external forces and moments acting on it are zero. 如果作用在固体上的所有外力和力矩的合力为零，则固体、结构或物理系统（或任何细分部分）无论是静止还是以恒定速度移动，都是处于静态平衡。 |
| Torsional angle (ϕ) | 扭转角（ψ） |
(Unit ° or rad) The angular deflexion between two locations on a straight bar subjected to a torque. （单位为°或rad）受扭矩作用的直杆上两个位置之间的角偏转。 |
| Combined carbon | 复合碳 |
The part of the total carbon in steel or cast iron that is present as other than free carbon. 钢或铸铁中总碳中除游离碳外的部分。 |
| Coarse threads | 粗螺纹 |
Threads with relatively large separation between corresponding points on the threads. 螺纹上相应点之间的间距相对较大的螺纹。 |
| Modulus of rupture | 断裂模量 |
Nominal stress at fracture in a bend test or torsion test. In bending, modulus of rupture is the bending moment at fracture divided by the section modulus. In torsion, modulus of rupture is the torque at fracture divided by the polar section modulus. 弯曲试验或扭转试验中的标称断裂应力。在弯曲中，断裂模量是断裂时的弯矩除以截面模量。在扭转中，断裂模量是断裂时的扭矩除以极截面模量。 |
| Shock load | 冲击载荷 |
The sudden application of an external force that results in a very rapid build-up of stress. 突然施加外力，导致应力迅速增加。 |
| Belt furnace | 带式炉 |
A continuous-type furnace which uses a mesh-type or cast-link belt to carry parts through the furnace. 一种连续式炉，它使用网状或铸造链带将零件运送通过炉子。 |
| Force ratio | 力比 |
The factor by which a simple machine multiplies an applied force. It is the ratio of the load (output force) to the effort (input force). 简单机器乘以所施加的力的因子。它是负载（输出力）与作用力（输入力）的比值。 |
| Proof strength (Unit Pa) | 验证强度（单位Pa） |
(proof stress, Rp, Rp,) The yield strength (offset yield strength) at some fixed value of the permanent strain given by the intersection of a line offset from, but parallel to, the elastic loading line and the engineering stress-engineering strain curve. The offset is arbitrary but is usually 0.1, 0.2, or 0.5% permanent strain (the proof strain). Used for materials which do not exhibit a sharply defined yield point. The notation Rp0.2 or Rp0.2 is employed for the 0.2% proof stress. （验证应力，Rp）在永久应变的某个固定值下的屈服强度（偏移屈服强度），由偏离但平行于弹性加载线的线与工程应力-工程应变曲线的交点给出。偏移是任意的，但通常为0.1、0.2或0.5%的永久应变（验证应变）。用于没有明确定义屈服点的材料。对于0.2%的验证应力，采用符号Rp0.2。 |
| Oxidation | 氧化 |
(1) A reaction in which there is an increase in valence resulting from a loss of electrons. (2) A corrosion reaction in which the corroded metal forms an oxide; usually applied to reaction with a gas containing elemental oxygen, such as air. （1）因电子损失而导致价态增加的反应。（2）腐蚀反应，其中被腐蚀的金属形成氧化物；通常用于与含有元素氧的气体如空气反应。 |
| Joint space | 关节空间 |
The description of the position and orientation of a robot in terms of the rotational angles and translational positions of the joints. Kinematic analysis, normally using homogeneous transforms, allows conversion between this description and the end‐effector position and orientation in x,y,z space. 根据关节的旋转角度和平移位置描述机器人的位置和方向。通常使用齐次变换的运动学分析允许在该描述与x、y、z空间中的末端执行器位置和方向之间进行转换。 |
| Ductility | 延展性 |
The ability of a material to deform plastically before fracturing. Measured by elongation or reduction in area in a tensile test, by height of cupping in a cupping test, or by the radius or angle of bend in a bend test. 材料在断裂前发生塑性变形的能力。通过拉伸试验中的伸长率或面积减少量、杯突试验中的杯突高度或弯曲试验中的弯曲半径或角度来测量。 |
| Plane strain | 平面应变 |
The stress condition in linear-elastic fracture mechanics in which there is zero strain in a direction normal to both the axis of applied tensile stress and the direction of crack growth (i.e., parallel to the crack front); most nearly achieved in loading thick plates along a direction parallel to the plate surface. Under plane-strain conditions, the plane of fracture instability is normal to the axis of the principal tensile stress. 线弹性断裂力学中的应力条件，其中在垂直于施加拉应力轴和裂纹扩展方向（即平行于裂纹前沿）的方向上存在零应变；最接近于沿平行于板表面的方向加载厚板。在平面应变条件下，断裂失稳平面垂直于主拉应力轴。 |
| Radiator | 散热器 |
A heat exchanger used to transfer thermal energy from one fluid to another for heating or cooling purposes. Despite the name, the principal mode of heat transfer is convection rather than radiation. In motor vehicles, water circulated through the engine block is cooled as it flows through the tubes of an air-cooled heat exchanger. In domestic radiators, hot water from a boiler is circulated through a heat exchanger with a large surface area which transfers heat to the surrounding air. 一种热交换器，用于将热能从一种流体传递到另一种流体，用于加热或冷却。尽管有这个名字，但热传递的主要方式是对流而不是辐射。在机动车辆中，通过发动机缸体循环的水在流经风冷热交换器的管道时被冷却。在家用散热器中，来自锅炉的热水通过具有大表面积的热交换器循环，该热交换器将热量传递给周围的空气。 |
| Case hardening | 表面硬化 |
A generic term covering several processes applicable to steel that change the chemical composition of the surface layer by absorption of carbon, nitrogen, or a mixture of the two and, by diffusion, create a concentration gradient. The processes commonly used are carburizing and quench hardening; cyaniding; nitriding; and carbonitriding. The use of the applicable specific process name is preferred. 一个通用术语，涵盖适用于钢的几种工艺，这些工艺通过吸收碳、氮或二者的混合物改变表层的化学成分，并通过扩散形成浓度梯度。常用的工艺有渗碳和淬火硬化，氰化，氮化以及碳氮共渗。优选使用适用的特定工艺名称。 |
| Stead’s brittleness | 斯特德脆性 |
A condition of brittleness that causes transcrystalline fracture in the coarse grain structure that results from prolonged annealing of thin sheets of low-carbon steel previously rolled at a temperature below about 705 °C (1300 °F). The fracture usually occurs at about 45° to the direction of rolling. 一种脆性状态，导致粗晶结构中发生穿晶断裂，这是由于之前在低于约705°C（1300°F）的温度下轧制的低碳钢薄板经过长时间退火造成的。断裂通常发生在与轧制方向约45°处。 |
| Absorber | 吸收器 |
1. An auxiliary vibratory system that favourably modifies the vibration characteristics of a main system. 2. Part of an absorption refrigeration system in which the refrigerant is absorbed by a transport medium. 3. The absorber plate is the receiver of a concentrating solar collector where the radiation is absorbed. 1.一种辅助振动系统，可有利地改变主系统的振动特性。2.吸收式制冷系统的一部分，其中制冷剂被传输介质吸收。3.吸收板是吸收辐射的聚光太阳能集热器的接收器。 |
| Transfer ratio | 传输比 |
(transfer constant) A complex variable representing the ratio between the output of a transducer and the input causing that output. （传递常数）一个复变量，表示传感器输出与产生该输出的输入之间的比率。 |
| Ductile fracture | 韧性断裂 |
Fracture characterized by tearing of metal accompanied by appreciable gross plastic deformation and expenditure of considerable energy. A fracture of a component or structure which is preceded by extensive ductile deformation so that the broken pieces cannot be re-fitted to regain the original size and shape of the component or structure. 以金属撕裂为特征的断裂，伴随着明显的总塑性变形和相当大的能量消耗。一种部件或结构的断裂，在断裂前会发生大范围的延性变形，从而使断裂的碎片无法重新装配以恢复部件或结构原来的尺寸和形状。 |
| Vertical engine | 立式发动机 |
A piston engine having the cylinders above the crankshaft. 气缸位于曲轴上方的活塞发动机。 |
| Free machining | 易切削 |
The property that makes machining easy because of the forming of small chips, a characteristic imparted to steel by sulfur, etc. 由于形成小切屑而使加工变得容易的特性，比如硫赋予钢的特性，等等。 |
| Binary vapour cycle | 二元蒸气循环 |
A power cycle which combines a steam cycle at relatively low temperature (the bottoming cycle) with a higher temperature cycle (the topping cycle) in which a working fluid such as mercury, sodium or potassium is used. 一种动力循环，它将相对低温的蒸汽循环（底部循环）与高温循环（顶部循环）相结合，其中使用了诸如汞、钠或钾之类的工作流体。 |
| Ventilation | 通风系统 |
A system for circulating fresh air in a room, building, passenger vehicle, orother enclosed space. 在房间、建筑物、乘用车或其他封闭空间中循环新鲜空气的系统。 |
| Forge | 锻造 |
To shape metal while holt and plastic by a hammering or forcing process. Dies used in process. 通过锤击或强制过程使金属成型，同时保持塑料成型。过程会使用模具。 |
| Cohesive zone | 凝聚力区 |
In fracture-mechanics modelling and simulation, the region at the crack tip over which an assumed traction (load-displacement) relation has to be overcome to permit initiation and propagation of a crack. 在断裂力学建模和模拟中，必须克服假定的牵引（载荷-位移）关系以允许裂纹萌生和扩展的裂纹尖端区域。 |
| Stress wave | 应力波 |
An unbalanced force, such as an impact, applied at one location in a body sets the material there into vibration that is transmitted to adjacent elements and ultimately to all parts of the body in the form of stress waves or wave packets. 施加在物体某个位置的不平衡力（如冲击力）会使物体中的材料产生振动，并以应力波或波包的形式传递到相邻元件，最终传递到物体的所有部位。 |
| Torque wrench | 扭矩扳手 |
A manual wrench which incorporates a gage or measuring apparatus of some sort to measure and display the amount of torque being delivered to the nut or bolt. All wrenches produce torque. Only a torque wrench tells how much torque. A socket wrench or ring spanner that can be set to allow a specific torque to be applied to a nut or bolt head. 一种手动扳手，包括某种量规或测量装置，用于测量和显示传递至螺母或螺栓的扭矩量。所有扳手都产生扭矩。只有扭矩扳手才能显示扭矩大小。一种套筒扳手或梅花扳手，可设置为允许对螺母或螺栓头施加特定扭矩。 |
| Turbine pump (turbopump) | 涡轮泵 |
An axial or centrifugal pump driven by a turbine. Typically used to supply fuel to the combustion chamber of a rocket engine such as on the space shuttle. 由涡轮驱动的轴向或离心泵。通常用于向火箭发动机（如航天飞机）的燃烧室供应燃料。 |
| Bypass ratio | 旁路比 |
In a turbofan engine, the ratio of the mass flow rate of the bypass stream to the mass flow rate through the core of the engine. 在涡扇发动机中，旁通流的质量流量与通过发动机核心的质量流量之比。 |
| Shrink fit | 过盈配合 |
A tight interference fit between two components resulting from heating an outer part and/or cooling an inner part to allow easy assembly. The outer component contracts on cooling, while the inner part expands on warming to ambient temperature, thus gripping the two parts together. 由于加热外部部件和/或冷却内部部件而导致的两个部件之间的紧密过盈配合，以便于组装。外部部件在冷却时收缩，而内部部件在加热到环境温度时膨胀，从而将两个部件夹在一起。 |
| Natural unit system (n.u. system) | 自然单位制（n.u.制） |
A non-SI system of units, based on fundamental constants, used in high-energy and particle physics. The n.u. of speed is the speed of light in a vacuum, c0 = 299 792 458 m/s. 基于基本常数的非国际单位制，用于高能和粒子物理n.u.速度是真空中的光速，c0=299792458m/s。 |
| Strain aging | 应变时效 |
The changes in ductility, hardness, yield point, and tensile strength that occur when a metal or alloy that has been cold worked is stored for some time. In steel, strain aging is characterized by a loss of ductility and a corresponding increase in hardness, yield point, and tensile strength. 已冷加工的金属或合金在储存一段时间后发生的延展性、硬度、屈服点和抗拉强度的变化。在钢中，应变时效的特点是延性损失，硬度、屈服点和抗拉强度相应增加。 |
| Shear | 扭剪 |
The type of force that causes or tends to cause two contiguous parts of the same body to slide relative to each other in a direction parallel to their plane of contact. 导致或倾向于导致同一物体的两个相邻部分在平行于其接触面的方向上相对滑动的力的类型。 |
| Sharp-notch strength | 锐缺口强度 |
The notch tensile strength measured using specimens with very small notch root radii (approaching the limit for machining capability); values of sharp-notch strength usually depend on notch root radius. 使用缺口根部半径非常小（接近加工能力极限）的试样测量的缺口抗拉强度；锐缺口强度值通常取决于缺口根部半径。 |
| Preload relaxation | 预载松弛 |
Local yielding, due to excess bearing stress under nuts and bolt heads (caused by high local spots, rough surface finish, and lack of perfect squareness of bolt and nut bearing surfaces), may result in preload relaxation after preloads are first applied to a bolt. 由于螺母和螺栓头下的轴承应力过大（由局部斑点高、表面粗糙以及螺栓和螺母轴承表面缺乏完美的方正度造成），局部屈服可能会在首次向螺栓施加预载荷后导致预载荷松弛。 |
| Wrap-around bend | 环绕弯曲 |
The bend obtained when a specimen is wrapped in a closed helix around a cylindrical mandrel. This term is sometimes applied to a semiguided bend of 180° or less. 当试样缠绕在圆柱形心轴周围的闭合螺旋中时获得的弯曲。该术语有时适用于180°或更小的半导弯曲。 |
| Pitch (Unit m) | 间距（单位：m） |
1. In a cascade of identical turbine or compressor blades, the distance between successive blades measured parallel to the leading edges. 2. For a screw thread, the distance between adjacent thread forms measured parallel to the thread axis. 3. For an aircraft, the vertical relationship between the nose and the horizon. The pitch axis is an axis in the plane of the wings of an aircraft, perpendicular to the centreline, about which the aircraft rotates. Pitch motion is the corresponding up or down movement of the aircraft nose. Pitch attitude is the angle between the centreline of an aircraft and the horizontal. The angle is positive when the nose is above its position when the centreline is horizontal. 1.在相同涡轮或压缩机叶片的叶栅中，平行于前缘测量的连续叶片之间的距离。2.对于螺纹，平行于螺纹轴线测量的相邻螺纹形状之间的距离。3.对于飞机，机头和水平线之间的垂直关系。俯仰轴是飞机机翼平面内垂直于中心线的轴，飞机绕中心线旋转。俯仰运动是飞机机头的相应向上或向下运动。俯仰姿态是飞机中心线与水平线之间的角度。当中心线水平时，当机头高于其位置时，角度为正。 |
| Compression | 压缩 |
1. Loading, the principal effect of which is to squeeze and shorten a component or testpiece. 2. The reduction in volume and increase in density of a substance as a consequence of increased pressure. 1.加载，其主要作用是挤压和缩短部件或试件。2.压力增加导致物质体积减少和密度增加。 |
| Maximum continuous load | 最大连续负载 |
(maximum continuous rating) (Unit kg/s) The maximum rate of steam output that a boiler can supply for a specified period, usually 24 hours. （最大连续额定功率）（单位为kg/s）锅炉在规定时间内（通常为24小时）可供应的最大蒸汽输出率。 |
| Carbon restoration | 碳修复 |
Replacing the carbon lost in the surface layer from previous processing by carburizing this layer to substantially the original carbon level. Sometimes called recarburizing. 通过将该层渗碳到基本上原始的碳水平来替换先前处理中在表面层中损失的碳。有时称为再碳化。 |
| Continuous precipitation | 连续沉淀 |
Precipitation from a supersaturated solid solution in which the precipitate particles grow by longrange diffusion without recrystallization of the matrix. Continuous precipitates grow from nuclei distributed more or less uniformly throughout the matrix. They usually are randomly oriented, but may form a Widmanstätten structure. 来自过饱和固溶体的沉淀，其中沉淀颗粒通过长程扩散生长而无需基质再结晶。连续析出物从在整个基体中或多或少均匀分布的核生长而来。它们通常是随机取向的，但可能形成魏氏结构。 |
| Thermal stresses | 热应力 |
Stresses in metal resulting from nonuniform temperature distribution. 由不均匀温度分布引起的金属应力。 |
| Unison ring | 协调环 |
In a turbomachine with adjustable guide or stator vanes, the ring to which a set of vanes is linked such that when the ring is rotated, all vane angles are adjusted. 在具有可调导向叶片或定子叶片的涡轮机中，一组叶片连接到的环，当环旋转时，所有叶片角度都可调整。 |
| A-basis | A-基础 |
Mechanical property value above which at least 99% of the population of values is expected to fall, with a confidence of 95%. Also called A-allowable. 机械性能值超过该值时，至少99%的值预计会下降，置信度为95%。也被称为A-容许。 |
| Acid rain | 酸雨 |
Any form of precipitation, including rain, snow, sleet, fog, dew, and particulates, which contains higher than normal levels of sulfuric and nitric acids. These acids result from natural and man-made emissions of sulfur dioxide and oxides of nitrogen, respectively. Acid soot consists of unburned carbon particles, typically larger than 10 μm, in the atmosphere contaminated with sulfuric acid. The particles result from poor combustion of fossil fuels. 任何形式的降水，包括雨、雪、雨夹雪、雾、露水和颗粒物，其中含有高于正常水平的硫酸和硝酸。这些酸分别来自二氧化硫和氮氧化物的自然排放和人为排放。酸烟灰由未燃烧的碳颗粒组成，通常大于10微米，在被硫酸污染的大气中。这些颗粒是化石燃料燃烧不良造成的。 |
| Physical properties | 物理性质 |
Properties of a material the determination of which does not involve the deformation or destruction of the specimen—for example, density, electrical conductivity, coefficient of thermal expansion, magnetic permeability, and lattice parameter. Does not include chemical reactivity or the properties more appropriately regarded as mechanical properties. 不涉及试样变形或破坏的材料特性，例如密度、电导率、热膨胀系数、磁导率和晶格参数。不包括化学反应性或更适当地视为机械的性质。 |
| Austenite finish temperature (Af) | 奥氏体完成温度（Af） |
Temperature at which the transformation of martensite into austenite completes upon heating. The same designation is also applied to nonferrous alloys in which martensite transforms into some parent phase. 加热时马氏体转变为奥氏体的温度。相同的名称也适用于马氏体转变为某些母相的有色合金。 |
| Two-stroke engine | 二冲程发动机 |
(two-cycle engine) A petrol or diesel engine in which an air/fuel charge is introduced through an induction port, compressed and burned, expanded and then exhausted through an exhaust port. The two ports in the cylinder wall are opened and closed by the piston. There are two strokes in each revolution of the crankshaft. In total-loss lubrication petrol engines, the lubricating oil is mixed with the fuel. （双循环发动机）一种汽油或柴油发动机，其中空气/燃料通过进气口引入，压缩和燃烧，膨胀，然后通过排气口排出。气缸壁上的两个口由活塞打开和关闭。曲轴每转一圈有两个冲程。在全失润滑汽油发动机中，润滑油与燃油混合。 |
| Slug wrench | 缓动扳手 |
A box wrench with an anvil on the end of the handle. Torque is produced by striking the anvil with a sledge hammer. 柄端有铁砧的套筒扳手。扭矩是通过用大锤敲击铁砧产生的。 |
| Double-shear test | 双剪试验 |
A shear test having two stationary, shear blades and one moving one and that uses solid round bars as test specimens. 一种剪切试验，具有两个固定的剪切刀片和一个移动的刀片，并使用实心圆棒作为试样。 |
| Clearance fit | 间隙配合 |
A range of clearances ranging from close sliding to loose running, i.e. a fit in which the limits for the mating parts always permit assembly. 从紧密滑动到松动运行的一系列间隙，即配合零件的限制始终允许组装的配合。 |
| X-ray thickness gauge | X射线厚度计 |
A device comprising an X-ray source and a detector used to determine the thickness of material in sheet or plate form, including metals, paper, plastics, rubber, and ceramics. 一种由X射线源和探测器组成的装置，用于测定片状或平板状材料的厚度，包括金属、纸张、塑料、橡胶和陶瓷。 |
| Millimetre of mercury | 毫米汞柱 |
A non-SI unit of pressure equal to the pressure exerted by a vertical column of mercury 1 mm high. Approximately equal to 133.3 Pa or 1 torr. 一种非SI压力单位，等于1毫米高的垂直水银柱施加的压力。大约等于133.3Pa或1托。 |
| Notch brittleness | 缺口脆性 |
Susceptibility of a material to brittle fractureat points of stress concentration. For example, in a notch tensile test, the material is said to be notch brittle if the notch strengthis less than the tensile strength of an unnotched specimen. Otherwise, it is said to be notch ductile. 材料在应力集中点易发生脆性断裂。例如，在缺口拉伸试验中，如果缺口强度小于无缺口试样的抗拉强度，则称材料为缺口脆性材料。否则，称其为缺口韧性。 |
| Displacement | 移位 |
The distance that a chosen measurement point on a cracked specimen displaces normal to the crack plane as the crack grows. 随着裂纹扩展，裂纹试样上选定的测量点垂直于裂纹平面位移的距离。 |
| Magnetic test | 磁性测试 |
Method used to test heat extraction rates of various quenchants. The test works by utilizing the change in magnetic properties of metals at their Curie point–the temperature above which metals lose their magnetism. 用于测试各种淬火剂的热提取率的方法。该测试通过利用金属在居里点（即金属失去磁性的温度）的磁性变化来进行。 |
| Damage tolerance | 损伤容限 |
(defect tolerance) A design philosophy that takes into account initial imperfections, crack-growth rates and conditions at final fracture, and uses fracture mechanics to demonstrate that cracks should not grow to their critical length within the design life (or at least should be capable of ready detection). （缺陷公差）考虑初始缺陷、裂纹扩展速率和最终断裂条件的设计理念，并使用断裂力学证明裂纹不应在设计寿命内增长到其临界长度（或至少应能够随时检测）。 |
| Dead space | 死区 |
(dead volume) (Unit m³) That volume of a gas-filled thermometer in which the gas is not at the same temperature as that being measured. （死容）（单位m³）充气温度计的体积，其中气体的温度与被测温度不同。 |
| Shim | 垫片 |
A thin piece of material, such as metal of accurately-known thickness, placed between two surfaces to ensure they are the correct distance apart. A thin piece of material placed between two surfaces to obtain a proper fit, adjustment, or alignment. The piece can also be analyzed to measure furnace carbon potential (that is, because while in the furnace it will quickly carburize to a level equal to the furnace carbon potential). 一块薄的材料，如厚度精确已知的金属，放置在两个表面之间，以确保它们之间的距离正确。放置在两个表面之间以获得适当配合、调整或对齐的一块薄材料。还可以对工件进行分析，以测量熔炉碳势（也就是说，在熔炉中，工件将快速渗碳至与熔炉碳势能相等的水平）。 |
| Thermodynamic pressure (Unit Pa) | 热力学压力（单位Pa） |
The pressure within a fluid given by an equation of state such as p(ρ,T) where ρ is the fluid density and T is the absolute temperature of the fluid. 流体中的压力由状态方程给出，如p（ρ，T），其中ρ是流体密度，T是流体的绝对温度。 |
| Blanking shear test | 落料剪力试验 |
A method used to determine the through-thickness shear strength of sheet material that involves blanking a disk out of flat strip using a simple punch-and-die method. Alson known as punching shear test. 一种用于确定板材全厚度剪切强度的方法，包括使用简单的冲模方法从扁平带材中冲裁出圆盘。也称为冲切试验。 |
| Tribology | 摩擦学 |
The science and technology concerned with interacting surfaces in relative motion. 与相对运动中相互作用的表面有关的科学和技术。 |
| Hydrogen embrittlement | 氢脆 |
A condition of low toughness, low ductility or cracking in metals resulting from the absorption of hydrogen. A common and troublesome form of Stress cracking. Several theories have been proposed to explain hydrogen embrittlement, but, at present, the exact mechanism is still unknown. What is known, however, is the fact that if hydrogen is trapped in a bolt by poor electroplating practices, it can encourage stress cracking. Bolts can fail, suddenly and unexpectedly, under normal loads. Premature crack growth over time under tensile stress leading to unexpected failure in certain metals, caused by small amounts of hydrogen in the microstructure. Hydrogen may enter steels during melting or heat treating, or during processes such as electroplating. 因吸收氢而导致金属韧性低、延展性低或开裂的情况，是一种常见且麻烦的应力开裂形式。在拉伸应力下，裂纹随时间过早扩展，导致某些金属发生意外失效，这是由微观结构中的少量氢引起的。在熔化或热处理过程中，或在电镀等过程中，氢可能进入钢中。已经提出了几种理论来解释氢脆，但目前，确切的机理仍然未知。已知的事实是，如果氢因电镀不当而被困在螺栓中，则会导致应力开裂。在正常载荷下，螺栓可能突然意外失效。 |
| Chilled castings | 冷铸件 |
Iron castings cooled at a rate that results in white iron (slow enough to avoid the formation of martensite, yet fast enough to prevent any silicon present from causing decomposition of cementite into iron and graphite). 铸铁件以产生白口铁的速度冷却（足够慢以避免形成马氏体，但足够快以防止任何存在的硅导致渗碳体分解成铁和石墨）。 |
| Blank nitriding | 空白渗氮 |
Simulating the nitriding operation without introducing nitrogen. This is usually accomplished by using an inert material in place of the nitriding agent or by applying a suitable protective coating to the ferrous alloy. 在不引入氮气的情况下模拟氮化操作。这通常通过使用惰性材料代替氮化剂或通过在铁合金上施加合适的保护涂层来实现。 |
| Spalling | 剥落 |
The separation of macroscopic particles from a surface in the form of flakes or chips. 以薄片或碎片形式从表面分离宏观颗粒。 |
| mechanical engineering | 机械工业 |
That branch of engineering concerned with energy conversion, stress analysis, vibration, dynamics, and kinematics, especially applied to design (machine design, mechanical-engineering design). 与能量转换、应力分析、振动、动力学和运动学有关的工程分支，尤其适用于设计（机器设计、机械工程设计）。 |
| Strain | 拉紧 |
The unit of change in the size or shape of a body due to force. Also known as nominal strain. 物体的大小或形状因力而变化的单位。也称为标称应变。 |
| Ductile crack propagation | 延性裂纹扩展 |
Slow crack propagation that is accompanied by noticeable plastic deformation and requires energy to be supplied from outside the body. 缓慢的裂纹扩展，伴随着明显的塑性变形，需要从外部提供能量。 |
| Valve spring | 气门弹簧 |
The spring that restores a valve to its closed position after having been opened, and is also intended to prevent valve bounce. 在阀门打开后将其恢复到关闭位置的弹簧，也用于防止阀门反弹。 |
| Concentrated load | 集中负荷 |
A load on a component which is distributed over a very small area, idealized as the line load of a wedge or knife edge, and the point load of a cone. 分布在非常小的区域上的部件上的载荷，理想化为楔形或刀刃的线载荷和锥体的点载荷。 |
| Condenser vacuum | 冷凝器真空 |
The sub-atmospheric pressure imposed on the condenser of a steam-power plant which leads to an appreciable increase in overall efficiency. 施加在蒸汽发电厂冷凝器上的低于大气压的压力导致整体效率显着提高。 |
| Thumb screw | 蝶形螺钉 |
A type of screw having a winged or knurled head for turning by hand when a quick and light clamping effect is desired. 一种螺钉，具有翼形或滚花头，当需要快速、轻夹紧效果时，可手动转动。 |
| Gage length | 标距 |
The original length of the portion of a specimen over which strain, change of length, or other characteristics are determined. 确定应变、长度变化或其他特性的试样部分的原始长度。 |
| Union (union joint) | 活接头 |
A threaded pipe fitting that allows two pipes to be connected anddetached without the need for either to be rotated, and without damaging the pipe ends. 一种螺纹管件，允许连接和拆卸两个管道，而无需旋转任何一个管道，且不会损坏管道端部。 |
| Kelvin (K) | 开尔文（K） |
The SI unit of temperature. The Kelvin temperature scale has a zero point at absolute zero and degree intervals (kelvins) the same size as degrees Celsius. The freezing point of water occurs at 273K (0ºC) and the boiling point at 373 K (100ºC). The base unit of thermodynamic temperature in the SI system. It was previously defined to be the fraction 1/273.16 of the thermodynamic temperature of the triple point of water. From 20 May 2019 it has been defined by taking the fixed numerical value of the Boltzmann constant kB to be 1.380 649 × 10−23 when expressed in the unit J/K, which is equal to kg.m²/(s²K). 国际单位制中热力学温度的基本单位。开尔文温度标度在绝对零度和与摄氏度大小相同的度间隔（开尔文）处有一个零点。水的冰点为273K（0ºC），沸点为373K（100ºC）。它先前被定义为水三相点热力学温度的分数1/273.16。从2019年5月20日起，通过将玻尔兹曼常数kB的固定数值取为1.380649×10来定义−当以等于kg·m²/（s²K）的单位J/K表示时。 |
| Secant modulus | 割线模量 |
The slope of the secant drawn from the origin to any specified point on a stress-strain curve. Compare with chord modulus. 从原点到应力应变曲线上任何指定点的割线斜率。与弦模量进行比较。 |
| Barrier protection | 屏障保护 |
The coating on a fastener is said to provide barrier protection if it merely isolates the fastener from the environment. Paint, for example, provides barrier protection. 如果仅将紧固件与环境隔离，则据说紧固件上的涂层可提供屏障保护。例如，油漆提供屏障保护。 |
| Absolute value error | 绝对值误差 |
The magnitude of the error dlsregarding the algebraic sign, or, for a vectorial error, disregarding its function. 关于代数符号的误差幅度，或者，对于矢量误差，不考虑其函数。 |
| Strain energy | 应变能 |
A measure of the energy absorption characteristics of a material determined by measuring the area under the stress-strain diagram. 通过测量应力-应变图下的面积确定的材料能量吸收特性的度量。 |
| Activation energy | 活化能 |
(Ea, U) (Unit kJ/mol) The minimum energy for a chemical reaction to occur or for processes such as diffusion to take place in crystals. （Ea, U）（单位kJ/mol）发生化学反应或在晶体中发生扩散等过程的最小能量。 |
| Relaxation curve | 松弛曲线 |
A plot of either the remaining, or relaxed, stress as a function of time. 剩余压力或松弛压力随时间变化的曲线图。 |
| Fatigue life (N) | 疲劳寿命（N） |
The number of cycles of stress or strain of a specified character that a given specimen sustains before failure occurs. 给定试样在失效发生之前所承受的特定特征的应力或应变的循环次数。 |
| Galilean transformation | 伽利略变换 |
In steady fluid flow, the addition or subtraction of a constant velocity to the entire flowfield, e.g. so that flow can be considered relative to a moving object or flow feature, such as a shock wave. 在稳定的流体流动中，对整个流场增加或减少恒定速度，例如，可以考虑相对于移动物体或流动特征（例如冲击波）流动。 |
| Dynamic load rating (Unit N) | 额定动载荷（单位N） |
The allowable load on a component or structure when the loading is not static. 当负载不是静态时，组件或结构上的允许负载。 |
| Die screw | 模具螺丝 |
Tool used when threading cylindrical pieces beyond the capacity of a die plate. 对超出模板容量的圆柱件进行螺纹加工时使用的工具。 |
| Elastic recovery | 弹性恢复 |
Amount the dimension of a stressed elastic material returns to its original (unstressed) dimension on release of an applied load. In hardness testing, the shortening of the original dimensions of the indentation upon release of the applied load. 在释放施加的载荷时，受应力弹性材料的尺寸恢复到其原始（无应力）尺寸的量。在硬度测试中，当释放所施加的载荷时，压痕的原始尺寸缩短。 |
| Friction | 摩擦 |
The resistance that a body encounters when sliding over another body, or experiences when a viscous fluid flows over its surface. 一个物体在另一个物体上滑动时遇到的阻力，或者当粘性流体流过其表面时所经历的阻力。 |
| Nut thickness | 螺母厚度 |
The nut thickness shall be the overall distance measured parallel to the axis of nut, from the top of the nut to the bearing surface, and shall include the thickness of the washer face where provided. 螺母厚度应为平行于螺母轴线测量的从螺母顶部到轴承表面的总距离，还应包括垫圈表面的厚度。 |
| Centrifugal pump | 离心泵 |
A pump into which liquid enters axially through the eye of the casing and is then accelerated through an impeller, thereby increasing both its kinetic energy and pressure before being delivered to a ring diffuser (the volute) that further increases the liquid pressure and from which it leaves. 一种泵，液体通过泵壳的眼轴向进入，然后通过叶轮加速，从而在输送到环形扩散器（蜗壳）之前增加其动能和压力，从而进一步增加液体压力并从中流出树叶。 |
| Shank | 螺杆 |
Portion of a bolt which lies under the head. 1. The stem of a tool, such as a broach, drill bit, reamer, or tap, which fits into a holder such as a chuck. 2. The stem of a rivet or the unthreaded part of a screw or bolt. 3. The shaft of a tool connecting the tip and the handle. 螺栓头部下方的部分。1.一种工具的柄部，如拉刀、钻头、铰刀或丝锥，可装入夹具（如卡盘）中。铆钉的杆或螺钉或螺栓的无螺纹部分。3.连接尖端和手柄的工具的轴。 |
| Computer numerical control (CNC) | 计算机数控（CNC） |
A term relating to machine tools in which the movements of a tool and/or the workpiece are controlled by computer. 与机床相关的术语，其中工具和/或工件的运动由计算机控制。 |
| Lathe | 车床 |
A machine tool in which work, gripped in the headstock, is rotated against the cutting tool to produce turned, bored, faced, or threaded components. 一种机床，其中夹持在主轴箱中的工件靠着切削工具旋转，以生产车削、钻孔、端面或螺纹部件。 |
| Fatigue notch factor (Kf) | 疲劳缺口系数（Kf） |
The ratio of the fatigue strength of an unnotched specimen to the fatigue strength of a notched specimen of the same material and condition; both strengths are determined at the same number of stress cycles. 无缺口试样的疲劳强度与相同材料和条件的有缺口试样的疲劳强度之比；两种强度都是在相同数量的应力循环下确定的。 |
| Planar anisotropy | 平面异向性 |
A variation in physical and/or mechanical properties with respect to direction within the plane of material in sheet form. 在片状材料平面内，物理和/或机械性能相对于方向的变化。 |
| Density | 密度 |
The mass per unit volume of a solid material. (mass density, ρ) (Unit kg/m³) The mass per unit volume of a substance that satisfies the continuum assumption. The reciprocal of specific volume. 固体材料每单位体积的质量。（质量密度，ρ）（单位kg/m³）满足连续统假设的物质每单位体积的质量。和比容相关联。 |
| Angström (Å) | 昂斯特罗姆（Å） |
An obsolete (non-SI) unit of length, sometimes still employed for atomic and crystallographic measurements. The conversion to SI is 1 Å = 10−10 m. 一种已被淘汰的（非SI）长度单位，有时仍用于原子和晶体学测量。转换为SI为1Å=10-10m。 |
| Process annealing | 中间退火 |
An imprecise term denoting various treatments used to improve workability. For the term to be meaningful, the condition of the material and the time-temperature cycle used must be stated. 一个不精确的术语，表示用于改善可加工性的各种处理方法。为了使术语有意义，必须说明材料的条件和使用的时间-温度循环。 |
| Hydrogen-induced delayed cracking | 氢致延迟开裂 |
A term sometimes used to identify a form of hydrogen embrittlement in which a metal appears to fracture spontaneously under a steady stress less than the yield stress. There is usually a delay between the application of stress (or exposure of the stressed metal to hydrogen) and the onset of cracking. Also referred to as static fatigue. 有时用于识别一种氢脆形式的术语，其中金属在小于屈服应力的稳定应力下似乎会自发断裂。在施加应力（或将受应力金属暴露于氢）与开裂开始之间通常存在延迟。也称为静态疲劳。 |
| Manometer | 压力计 |
An instrument used in the measurement of a pressure difference in a fluid (manometry). 用于测量流体压力差（测压）的仪器。 |
| Quench-age embrittlement | 淬火时效脆化 |
Embrittlement of low-carbon steels resulting from precipitation of solute carbon at existing dislocations and from precipitation hardening of the steel caused by differences in ferrite at different temperatures. Quenchage embrittlement usually is caused by rapid cooling of the steel from temperatures slightly below Ac1 (the temperature at which austenite begins to form), and can be minimized by quenching from lower temperatures. 低碳钢的脆化是由于溶质碳在现有位错处的沉淀和铁素体在不同温度下的差异导致的钢沉淀硬化造成的。淬火脆性通常是由钢从略低于Ac1的温度（奥氏体开始形成的温度）快速冷却引起的，可以通过从较低温度淬火来最小化。 |
| Crest clearance (Unit m) | 顶隙（单位米） |
For screw threads and gearing, the radial clearance between the crest of a thread (or gear) and the root of the engaging thread (or gear). 对于螺纹和齿轮，螺纹（或齿轮）的顶部与啮合螺纹（或齿轮）的根部之间的径向间隙。 |
| Castellated nut | 槽形螺母 |
A nut having slots across the hexagonal faces, used with a bolt having a drilled hole so that a split (cotter) pin may be inserted through both nut and bolt to prevent unscrewing. 一种在六角面上有槽的螺母，与具有钻孔的螺栓一起使用，以便将开口（开口）销插入穿过螺母和螺栓以防止拧松。 |
| Compression wave | 压缩波 |
(dilatation wave) In a fluid or a solid, a progressive wave or wavefront that compresses the medium through which it propagates. （膨胀波）在流体或固体中，压缩介质传播的行波或波前。 |
| Structural analysis | 结构分析 |
The determination of the forces, displacements, stresses, and strains in a given structure. 确定给定结构中的力、位移、应力和应变。 |
| Torsion spring | 扭簧 |
1. A spring in the form of a torsion bar. 2. A helical spring to which torque can be applied at the ends. 1.一种扭杆形式的弹簧。2.一种螺旋弹簧，其端部可施加扭矩。 |
| Elasticity | 弹性 |
The property of a material by virtue of which deformation caused by stress disappears on removal of the stress. A perfectly elastic body completely recovers its original shape and dimensions after release of stress. 一种材料的特性，通过这种特性，由应力引起的变形在去除应力后消失。完全弹性体在应力释放后完全恢复其原始形状和尺寸。 |
| Self-loosening | 自松动 |
The process by which a supposedly tightened fastener becomes loose, as a result of vibration, thermal cycles, shock, or anything else which cause transverse slip between joint members and between male and female threads. Vibration loosening is a common, but special, case of self-loosening. 由于振动、热循环、冲击或任何其他导致接头构件之间以及阳螺纹和阴螺纹之间横向滑动的原因，紧固件松动的过程。振动松动是自松动的一种常见但特殊的情况。 |
| Compression fitting | 压缩接头 |
A screwed joint for pipework made resistant to leakage by permanent deformation of a closely-fitting ring, called a ferrule or olive, on tightening. 一种用于管道的螺纹接头，通过紧密配合的环（称为套圈或橄榄形）在拧紧时的永久变形来防止泄漏。 |
| Available resource | 可用资源 |
(total resource) (Unit J) The total annual energy theoretically available from a renewable-energy source, such as ocean waves, the wind, or the total incident solar energy. （总资源）（单位J）理论上可从可再生能源（例如海浪、风或总入射太阳能）获得的年度总能量。 |
| Biodiesel | 生物柴油 |
A substitute for diesel fuel derived from the oily seeds of sunflowers, oilseed rape, soya beans, etc. 从向日葵、油菜、大豆等的油性种子中提取的柴油的替代品。 |
| Free ferrite | 游离铁氧体 |
Ferrite that is formed directly from the decomposition of hypoeutectoid austenite during cooling, without the simultaneous formation of cementite. Also proeutectoid ferrite. 在冷却过程中亚共析奥氏体分解直接形成的铁素体，没有同时形成渗碳体。也是先共析铁氧体。 |
| Impact extrusion | 冲击挤压 |
The extrusion of separate components of soft metals whose properties permit the action to be performed quickly. 挤压单独的软金属组件，其特性允许快速执行操作。 |
| Equation, short form | 方程式，简写形式 |
An empirical equation which relates the torque applied to the bolt to the preload created in it, and which depends mainly on an experimentally derived factor called the Nut factor. 一个经验公式，将施加在螺栓上的扭矩与螺栓中产生的预载荷联系起来，主要取决于一个称为螺母系数的实验得出的系数。 |
| Three-quarters hard | 四分之三硬度 |
A temper of nonferrous alloys and some ferrous alloys characterized by tensile strength and hardness about midway between those of half hard and full hard tempers. 一种非铁合金和一些铁合金的回火，其特征是抗拉强度和硬度介于半硬回火和全硬回火之间。 |
| Radial flow | 径向流 |
radial flow Fluid flow for which the principal direction of flow is either radially inward or radially outward relative to an axial direction. 径向流动流体流动的主要方向是径向向内或径向向外流动。 |
| Coherent precipitate | 相干沉淀 |
A crystalline precipitate that forms from solid solution with an orientation that maintains continuity between the crystal lattice of the precipitate and the lattice of the matrix, usually accompanied by some strain in both lattices. Because the lattices fit at the interface between precipitate and matrix, there is no discernible phase boundary. 由固溶体形成的结晶沉淀物，其取向保持沉淀物晶格和基体晶格之间的连续性，通常伴随着两个晶格中的一些应变。由于晶格适合于沉淀和基体之间的界面，因此不存在可识别的相边界。 |
| Auxiliary power unit (APU) | 辅助动力装置（APU） |
In aircraft–gas–turbine applications, a small gas turbine used to provide start-up power, electrical and hydraulic power, and compressed air for cabin ventilation. In other applications, an APU may be a gas turbine or internal-combustion engine used to provide emergency power. 在飞机-燃气轮机应用中，小型燃气轮机用于提供启动动力、电力和液压动力以及用于机舱通风的压缩空气。在其他应用中，APU可以是用于提供应急动力的燃气轮机或内燃机。 |
| Transmissibility | 传递率 |
The ratio of the transmitted force to the disturbing force for a system subjected to a vibratory disturbance. The ratio may also be defined in terms of displacements, velocities, or accelerations. 受到振动干扰的系统的传递力与干扰力之比。该比率也可以用位移、速度或加速度来定义。 |
| Cleavage fracture | 解理断裂 |
A fracture, usually of a polycrystalline metal, in which most of the grains have failed by cleavage, resulting in bright reflecting facets. It is one type of crystalline fracture and is associated with low energy brittle fracture. Contrast with shear fracture. A fracture created by splitting (cleavage), as between layers in materials like slate or mica. In brittle metals, and brittle microconstituents in alloys, cleavage occurs along particular crystal planes. 一种通过分裂（劈裂）产生的裂缝断裂，通常是多晶金属的断裂，其中大部分晶粒因解理而失效，产生明亮的反射面。它是一种结晶性断裂，与低能脆性断裂有关。与剪切断裂相对。如板岩或云母等材料的层之间。在脆性金属和合金中的脆性微量成分中，沿特定晶面发生解理。 |
| constitutive equation | 本构方程 |
(constitutive relation) 1. In solid mechanics or fluid mechanics, an algebraic or numerical relation for the dependency of stress on deformation, strain, strain rate, temperature, etc. in a material. In solid mechanics such a relation is sometimes called an equation of state. Simple linear examples include Hooke’s law and Newton’s viscosity law. 2. In heat transfer, a relation, such as Fourier’s law of heat conduction, connecting heat flux with temperature gradient. （本构关系）1.在固体力学或流体力学中，应力与材料的变形、应变、应变率、温度等之间的代数或数值关系。在固体力学中，这种关系有时称为状态方程。简单的线性例子包括胡克定律和牛顿粘度定律。2.在传热学中，将热流与温度梯度联系起来的一种关系，如傅立叶热传导定律。 |
| Decarburization | 脱碳 |
Loss of carbon from the surface layer of a carbon-containing alloy due to reaction with one or more chemical substances in a medium that contacts the surface. 由于与接触表面的介质中的一种或多种化学物质发生反应，含碳合金表面层的碳损失。 |
| Total heat (Unit kJ) | 总热量（单位kJ） |
An alternative term for enthalpy. It is inappropriate as it suggests that it includes kinetic energy in the same way as total enthalpy, but it does not. Also, heat and enthalpy are quite different quantities, as their definitions show. 焓的另一个术语。这是不恰当的，因为它表明，它包括动能的方式与总焓相同，但它实际上并不是的。此外，热和焓是完全不同的量，正如它们的定义所示。 |
| Mohs hardness test | 莫氏硬度测试 |
A scratch hardness test for determining comparative hardness using 10 standard minerals—from talc (the softest) to diamond (the hardest). 刮擦硬度测试，用于使用从滑石（最软）到钻石（最硬）的10种标准矿物测定比较硬度。 |
| Tensioner | 张紧器 |
A hydraulic tool used to tighten a fastener by stretching it rather than by applying a substantial torque to the nut. After the tension has stretched the bolt or stud, the nut is run down against the joint with a modest torque, and the tensioner is disengaged from the fastener. The nut holds the stretch produced by the tensioner. 一种液压工具，用于通过拉伸紧固件而不是对螺母施加较大扭矩来拧紧紧固件。张力拉伸螺栓或螺柱后，以适当的扭矩将螺母向下压靠接头，张紧器与紧固件分离。螺母保持张紧器产生的拉伸。 |
| Absorption | 吸收 |
The process whereby a fluid permeates a porous solid, or a gas is dissolved by a liquid. 流体渗透多孔固体或气体被液体溶解的过程。 |
| Spring constant | 弹簧常数 |
The ratio between the forces exerted on a spring (or a bolt) and the deflection thereof. Has the dimensions of force per unit change in length (e.g., lb=in.). Also called Stiffness. 施加在弹簧（或螺栓）上的力与其挠度之间的比率。具有每单位长度变化的力的尺寸（例如lb=in.）。也称为刚度。 |
| Tensile strength (Unit Pa) | 抗拉强度（单位Pa） |
In tension testing, the ratio of maximum load to original cross-sectional area. Also known as ultimate strength. The resistance that a material offers to tensile stress. It is defined as the smallest tensile stress required to break the body. (ultimate strength, ultimate tensile strength, UTS, Rm, Rm) The nominal or engineering stress given by the maximum load in a tension test divided by the original cross-sectional area of the specimen. The maximum load could be the fracture load for a brittle material, but for a ductile material it is usually taken as the load at which necking begins, beyond which the load falls. 在拉伸试验中，最大载荷与原始横截面积之比。也称为极限强度。材料对拉伸应力的抵抗力。它被定义为破坏主体所需的最小拉伸应力。（极限强度、极限抗拉强度、UTS、Rm、Rm）拉伸试验中最大载荷除以试样原始横截面积得出的标称或工程应力。对于脆性材料，最大载荷可以是断裂载荷，但对于韧性材料，最大荷载通常被视为颈缩开始时的载荷，超过该载荷时，载荷下降。 |
| Fatigue striations | 疲劳条纹 |
Parallel lines frequently observed in electron microscope fractographs or fatigue-fracture surfaces. The lines are transverse to the direction of local crack propagation; the distance between successive lines represents the advance of the crack front during the one cycle of stress variation. 在电子显微镜断口图或疲劳断口表面中经常观察到平行线。这些线横向于局部裂纹扩展方向；连续线之间的距离表示在一个应力变化周期内裂纹前沿的前进。 |
| Plastic deformation | 塑性变形 |
The permanent (inelastic) distortion of a material under applied stress that strains the material beyond its elastic limit. 材料在施加应力下的永久（非弹性）变形，使材料应变超过其弹性极限。 |
| Hydrogen damage | 氢损伤 |
A general term for the embrittlement, cracking, blistering, and hydride formation that can occur when hydrogen is present in some metals. 当氢存在于某些金属中时可能发生的脆化、开裂、起泡和氢化物形成的总称。 |
| Absolute pressure | 绝对压力 |
1. The pressure measured relative to zero pressure (vacuum). 2. Gage pressure plus barometric pressure in the same units. 1.相对于零压力（真空）测量的压力。2.表压加上大气压力的单位相同。 |
| Radian (rad) | 弧度（rad） |
A coherent derived SI unit defined as the plane angle subtended at the centre of a circle by an arc having a length equal to the radius. Thus 2π radians are equivalent to 360° and 1 rad ≈ 57.3°. 一种相干导出的国际单位制单位，定义为在圆心处被长度等于半径的弧对向的平面角。因此，2π弧度相当于360°和1弧度≈57.3°. |
| Precipitation-hardenable stainless steels | 沉淀硬化不锈钢 |
Precipitation-hardenable stainless steels contain typically 11–18% chromium, 3–10% nickel, 0.05–0.2% carbon, and small additions of manganese, silicon, aluminium, molybdenum, niobium and titanium. These steels can be supplied in a solution-treated condition, which is readily fabricated or machined, and then hardened by an ageing treatment that produces a fine dispersion of second-phase precipitates. They are available in austenitic, semi-austenitic, and martensitic grades. Uses include springs, knives, and pressure vessels. 沉淀硬化不锈钢通常含有11-18%的铬、3-10%的镍、0.05-0.2%的碳以及少量添加的锰、硅、铝、钼、铌和钛。这些钢可在固溶处理条件下供应，该条件易于制造或机加工，然后通过时效处理硬化，从而产生细小的第二相沉淀。它们有奥氏体、半奥氏体和马氏体等级。用途包括弹簧、刀具和压力容器。 |
| Fatigue | 疲劳 |
The phenomenon leading to fracture under repeated or fluctuating stresses having a maximum value less than the ultimate tensile strength of the material. Fatigue failure generally occurs at loads that, applied statically, would produce little perceptible effect. Fatigue fractures are progressive, beginning as minute cracks that grow under the action of the fluctuating stress. A term referring, in components and structures subjected to either random or cyclic periodically-varying loads, to a progressive reduction in strength leading to failure at stresses lower than those that cause failure under monotonic loading. Variable loads arise from outof-balance machinery and other vibration sources, wind gusts, etc., and a large proportion of service failures is caused by fatigue. Fatigue results from the initiation and slow propagation of cracks. In manufactured components, crack initiation usually occurs at a point of stress concentration. After a period, often of millions of stress cycles, the crack reaches a critical length at which the next peak load causes sudden brittle or ductile fracture. Fracture surfaces resulting from fatigue display characteristic striations or progression marks emanating from the crack initiation site during the slow crack growth period, with a different surface appearance for the final fracture. 在最大值小于材料极限抗拉强度的重复或波动应力下导致断裂的现象。疲劳失效通常发生在静态施加的载荷下，不会产生明显影响。疲劳断裂是渐进性的，从在波动应力作用下生长的微小裂纹开始。在承受随机或周期性变化载荷的部件和结构中，指强度逐渐降低，导致在低于单调载荷下导致失效的应力下发生失效的术语。可变负载由失衡的机械和其他振动源、阵风等引起，大部分故障是由疲劳引起的。疲劳是裂纹萌生和缓慢扩展的结果。在制造部件中，裂纹萌生通常发生在应力集中点。在一段时间（通常是数百万次应力循环）后，裂纹达到临界长度，此时下一个峰值载荷会导致突然脆性或韧性断裂。疲劳产生的断裂表面在缓慢裂纹扩展期间显示出从裂纹萌生部位发出的特征条纹或进展标记，最终断裂的表面外观不同。 |
| Volumetric efficiency | 容积效率 |
For a piston engine, the ratio of the volume of the induced charge per induction stroke, determined at a reference pressure and temperature, to the swept volume. 对于活塞式发动机，在参考压力和温度下确定的每个进气冲程的进气体积与扫掠体积之比。 |
| Arbitration bar | 抗弯试棒 |
A test bar, cast with a heat of material, used to determine chemical composition, hardness, tensile strength, and deflection and strength under transverse loading in order to establish the state of acceptability of the casting. 用热材料铸造的测试棒，用于确定化学成分、硬度、抗拉强度、横向载荷下的挠度和强度，以确定铸件的可接受状态。 |
| Finishing washer | 光制垫圈 |
A washer designed for use with countersunk screws. Used to enhance appearance in some applications. 设计用于沉头螺钉的垫圈。在某些应用中用于增强外观。 |
| Boyle’s law | 波义耳定律 |
The product of the pressure of a gas p and its volume is constant at a given absolute temperature T. Together with Charles law, it yields the ideal gas equation p = Mrt where m is the mass of gas and R is the specific gas constant. The volume of a gas at constant temperature is inversely proportional to the pressure. This means that as pressure increases, the volume of a gas decreases. 在给定的绝对温度T下，气体的压力p与其体积的乘积是恒定的。与查尔斯定律一起，它产生了理想的气体方程p=Mrt，其中m是气体的质量，R是特定的气体常数。恒温下气体的体积与压力成反比。这意味着随着压力的增加，气体的体积会减少。 |
| Hardness test | 硬度测试 |
1. Any of various tests in which different hard indenters are forced into the surface of a solid under different loads to give permanent impressions, the pressure to cause which being called the hardness. The Brinell test employs a spherical indenter; the Vickers test a square-based pyramid. The relation between indentation hardness H and uniaxial yield stress Y is approximately H = (2.5 ~ 3.0)Y. Originally hardnesses were given in kg/mm² but now are often given in Pa. 2. The tests for scratch and file hardness relate either to one material being able to mark another (Mohs hardness scale for minerals), or to the size of groove produced by a rigid indenter slid under load across a surface. 3. Rebound hardness concerns the height of rebound of a dropped indenter, or an indenter at the end of a pivoted arm, having struck a surface. 1.任何一种试验，其中不同的硬压头在不同载荷下压入固体表面，以产生永久压痕，所产生的压力称为硬度。布氏试验采用球形压头；维氏硬度测试是一个方形金字塔。压痕硬度H与单轴屈服应力Y之间的关系约为H=（2.5~3.0）Y。最初硬度以kg/mm²为单位，但现在通常在Pa.2中给出。划痕和锉刀硬度测试要么与一种材料能够标记另一种材料（矿物的莫氏硬度标度）有关，要么与刚性压头在表面上滑动产生的凹槽大小有关。3.回弹硬度涉及掉落压头或旋转臂端部压头撞击表面后的回弹高度。 |
| Initial stress | 初始应力 |
The stress produced by strain in a specimen immediately on achieving the given constant-strain conditions in a stress-relaxation test before stress-relaxation occurs. Sometimes referred to as instantaneous stress. 在应力松弛发生之前，在应力松弛试验中达到给定的恒定应变条件时，试样立即应变所产生的应力。有时称为瞬时压力。 |
| Total combustion air (Unit kg/s) | 总燃烧空气（单位：kg/s） |
1. The combination of the stoichiometric flow of air required for combustion together with any excess air. 2. The flow of fresh air into a boiler plus any flue gas recirculated. 1.燃烧所需的化学计量空气流与任何过量空气的组合。2.进入锅炉的新鲜空气流加上再循环的任何烟气。 |
| Ideal critical diameter | 理想临界直径 |
(DI). Under an ideal quench condition, the bar diameter that has 50% martensite at the center of the bar when the surface is cooled at an infinitely rapid rate (that is, when H = ∞, where H is the quench severity factor). （DI）在理想淬火条件下，当表面以无限快的速度冷却时（即H=∞, 其中H是淬火严重度因子）。 |
| Pop rivet | 拉钉 |
A hollow rivet that enables a connexion to be made from one side only of an assembly. 一种空心铆钉，使连接只能从组件的一侧进行。 |
| Two-dimensional flow | 二维流 |
A fluid flow in which the velocity at any time depends upon two spatial coordinates, such as the radial and axial locations in developing pipe flow. 一种流体流动，其中任何时候的速度取决于两个空间坐标，如发展中的管道流中的径向和轴向位置。 |
| Graphitic carbon | 石墨碳 |
Free carbon in steel or cast iron. 钢或铸铁中的游离碳。 |
| Unit | 单位 |
A numerical indication of the magnitude of a physical quantity. The basic units of mass, length, time, etc. are relative to agreed standards. 物理量大小的数字指示。质量、长度、时间等基本单位与商定的标准相对应。 |
| Pitch-circle diameter (Unit m) | 节圆直径（单位：m） |
The diameter of the circle (the pitch circle) centred on a component’s axis, around which holes or bolts are equally spaced. 以部件轴为中心的圆（节圆）的直径，孔或螺栓围绕其等距分布。 |
| Durometer hardness | 硬度计硬度 |
Measure of the indentation hardness of plastics. It is the extent to which a spring-loaded steel indenter protrudes beyond the pressure foot into the material. 塑料压痕硬度的测量。它是弹簧加载的钢压头超出压力脚伸入材料的程度。 |
| Oxidizing agent | 氧化剂 |
A compound that causes oxidation, thereby itself becoming reduced. 一种引起氧化从而自身被还原的化合物。 |
| Square | 正方 |
1. A regular quadrilateral, i.e. a polygon with four equal sides and four right angles. 2. An instrument to check angles of internal and external surfaces and flatness. 1.正四边形，即具有四条等边和四个直角的多边形。2.一种检查内外表面角度和平面度的仪器。 |
| Ideal gas laws | 理想气体定律 |
The law relating pressure, temperature and volume of an ideal (perfect) gas pV = mRT, where R is the gas constant. The law implies that at constant temperature T, the product of pressure p and volume V is constant (Boyle’s law), and at constant pressure, the volume is proportional to the temperature (Charles’ law). 与理想（完美）气体的压力、温度和体积相关的定律pV=mRT，其中R是气体常数。该定律意味着在恒定温度T下，压力p和体积V的乘积是恒定的（波义耳定律），而在恒定压力下，体积与温度成正比（查尔斯定律）。 |
| Safe working load (Unit N) | 安全工作负荷（单位：N） |
The steady or unsteady load against which a component or structure is designed for normal operation. It is lower than that which would cause failure by buckling, fracture, or yielding, so as to accommodate uncertainty, possible fault or accident conditions. 部件或结构设计用于正常运行的稳定或不稳定荷载。该值低于因屈曲、断裂或屈服而导致失效的值，以适应不确定性、可能的故障或事故条件。 |
| Scoring | 划痕 |
In tribology, a severe form of wear characterized by the formation of extensive grooves and scratches in the direction of sliding. 在摩擦学中，一种严重的磨损形式，其特征是在滑动方向上形成大面积的凹槽和划痕。 |
| Shoulder bolt | 轴肩螺栓 |
A bolt for which the unthreaded cylindrical section between the thread and the head is of larger diameter than the threaded section, precisely machined to length and diameter and hardened 一种螺栓，其螺纹和头部之间的无螺纹圆柱段的直径大于螺纹段的直径，精确加工至长度和直径并硬化 |
| Tangent screw | 微动螺旋 |
A worm screw used to adjust measuring instruments such as sextants and vernier callipers. 用于调整六分仪和游标卡尺等测量仪器的蜗杆。 |
| Bypass valve | 旁通阀 |
A valve that directs flow through a bypass. 引导流过旁路的阀门。 |
| Verified loading range | 验证加载范围 |
For testing machines, the range of indicated loads for which the testing machine gives results within the permissible variation specified. 对于试验机，试验机在规定允许偏差范围内给出结果的指示载荷范围。 |
| Stability | 稳定性 |
1. A term relating to whether a body, structure, system, or flow is in a state of stable, unstable, or neutral equilibrium. 2. In numerical analysis, whether numerical errors, such as roundoff or input-data errors, are damped, propagate, or cause divergence of the solution as the numerical method proceeds. 3. A control system is often described as stable when a step change in input results in a steady output without continuing oscillation. 1.与物体、结构、系统或流是否处于稳定、不稳定或中性平衡状态有关的术语。2.在数值分析中，随着数值方法的进行，数值误差（如舍入误差或输入数据误差）是否衰减、传播或导致解发散。3.当输入的阶跃变化导致稳定输出而无持续振荡时，控制系统通常被描述为稳定的。 |
| Dilatometer | 膨胀计 |
An instrument for measuring length or volume changes in a solid during heating and subsequent cooling or isothermal holding. · An instrument for measuring the linear expansion or contraction in a metal resulting from changes in such factors as temperature and allotropy. 一种在加热和随后的冷却或等温保持过程中测量固体长度或体积变化，测量金属因温度和同素异形体等因素的变化而引起的线性膨胀或收缩的仪器。 |
| Carburizing flame | 渗碳火焰 |
A gas flame that will introduce carbon into some heated metals, as during a gas welding operation. A carburizing flame is a reducing flame, but a reducing flame is not necessarily a carburizing flame. 一种气体火焰，会在气焊操作中将碳引入一些加热的金属中。渗碳火焰是还原火焰，但还原火焰不一定是渗碳火焰。 |
| Composite material | 复合材料 |
(composite structure) A general term used of two or more materials or structures acting in combination (e.g. concrete, reinforced concrete, filamentreinforced polymers, laminated materials, particulate-reinforced materials, flitched beams), resulting in values of strength, stiffness, or toughness greater than the base matrix material alone. （复合结构）用于组合作用的两种或多种材料或结构的通用术语（例如混凝土、钢筋混凝土、纤维增强聚合物、层压材料、颗粒增强材料、切割梁），从而产生强度、刚度或韧性值大于单独的基体材料。 |
| Acicular ferrite | 针状铁素体 |
A highly substructured non-equiaxed ferrite that forms upon continuous cooling by a mixed diffusion and shear mode of transformation that begins at a temperature slightly higher than the temperature transformation range for upper bainite. It is distinguished from bainite in that it has a limited amount of carbon available; thus, there is only a small amount of carbide present. Ferrite crystallite growing, apparently, as in the course of bainitic transformation. It has a lath-like shape and an increased dislocation 一种高度亚结构的非等轴铁素体，在连续冷却时通过混合扩散和剪切相变模式形成，其开始温度略高于上贝氏体的温度转变范围。它与贝氏体的区别在于它的碳含量有限。因此，仅存在少量碳化物。显然，铁素体微晶在贝氏体转变过程中生长。它具有板条状的形状和增加的位错。 |
| Air classifier | 空气分级机 |
(air elutriator) A device in which an airstream, which may be swirling, sorts particles by a combination of size, shape, and mass. （空气淘析器）一种装置，在该装置中，气流（可能是漩涡）根据大小、形状和质量的组合对颗粒进行分类。 |
| Poisson’s ratio (ν) | 泊松比（ν） |
The absolute value of the ratio of transverse (lateral) strain to the corresponding axial strain resulting from uniformly distributed axial stress below the proportional limit of the material. 横向（侧向）应变与相应轴向应变之比的绝对值，该比值由低于材料比例极限的均匀分布的轴向应力产生。 |
| Hot isostatic pressing | 热等静压 |
Sintering of powdered materials at high temperature and high hydrostatic pressure in order to minimize porosity. 在高温和高静水压力下烧结粉末材料，以尽量减少孔隙率。 |
| Screw feeder | 螺旋给料机 |
A mechanism for handling bulk materials in which a rotating helicoidal screw moves the material axially forward. Similar to a screw conveyor, but required to discharge material at a controlled rate very accurately. It operates with the screw completely full. 一种用于处理散装物料的机构，其中旋转的螺旋螺杆使物料轴向向前移动。类似于螺旋输送机，但需要以受控速率非常精确地排出物料。它在螺杆完全充满的情况下运行。 |
| Pin expansion test | 插头膨胀试验 |
A test for determining the ability of a tube to be expanded or for revealing the presence of cracks or other longitudinal weaknesses in it, made by forcing a tapered pin into the open end of the tube, similar to flare test. 通过将锥形销压入管道开口端来确定管道膨胀能力或揭示其存在裂纹或其他纵向缺陷的试验，类似于扩口试验。 |
| Bolt blank | 螺栓毛坯 |
A rod on which a head has been formed, but on which no thread has been cut, from which bolts or screws may be made as required. 一种已形成头部但未切割螺纹的杆，可根据需要从中制造螺栓或螺钉。 |
| Hot working | 热加工 |
Plastic deformation of a metal, by rolling, drawing, forging, etc., at a temperature above its recrystallization temperature (in commercial alloys above about 40% of their melting points in kelvins) which results in permanent shape change but no increase in strength or loss of ductility. 金属通过轧制、拉拔、锻造等在高于其再结晶温度（在商业合金中高于其熔点的40%的开尔文）的温度下发生塑性变形，导致永久的形状变化，但不会增加强度或失去延展性。 |
| Vibrometer | 测振仪 |
A device used to measure the motion of a vibrating surface, typically using a contactless laser-based technique. 一种用于测量振动表面运动的装置，通常使用非接触激光技术。 |
| Die | 模具 |
1. A tool having an appropriately-shaped hole through which material may be extruded or drawn. 2. A tool employed in forging. 3. A block having the male or female shape employed in stamping operations. 4. A thick circular disc, driven by a die wrench, with internally-threaded cutting edges for producing a screw thread. A die wrench (die stock) holds a screw-cutting die and has two projecting arms for applying the torque necessary to cut the thread. A die having a hexagonal or square shape (die nut), driven by a spanner, is used in confined spaces where a die wrench cannot be rotated through a full circle. 1.一种具有适当形状的孔的工具，通过该孔可以挤压或拉伸材料。2.一种用于锻造的工具。3.一种用于冲压操作的具有阳或阴形状的块体。4.一种由模具扳手驱动的厚圆盘，具有用于产生螺纹的内螺纹切削刃。冲模扳手（冲模）装有一个螺旋切割模，并有两个突出臂，用于施加切割螺纹所需的扭矩。由扳手驱动的六边形或方形模具（模具螺母）用于模具扳手无法旋转一整圈的受限空间。 |
| Balance weight | 平衡器 |
A corrective mass used in the static or dynamic balancing of a rotating object. 用于旋转物体的静态或动态平衡的校正质量。 |
| Aerated bath nitriding | 空气搅拌液体渗氮法 |
A type of liquid nitriding in which air is pumped through the molten bath creating agitation and increased chemical activity. 一种液体氮化，其中空气被泵入熔池，产生搅拌并增加化学活性。 |
| Cavity radiator | 空腔辐射器 |
A heated chamber having a small hole through which radiation, approximating blackbody radiation, passes out. 具有小孔的加热室，近似于黑体辐射的辐射通过该小孔传递出去。 |
| Hypereutectoid alloy | 过共析合金 |
In an alloy system exhibiting a eutectoid, any alloy whose composition has an excess of alloying element compared with the eutectoid composition, and whose equilibrium microstructure contains some eutectoid structure. 在呈现共晶的合金系统中，合金成分比共晶成分多的任何合金，其平衡微观结构包含一些共晶结构。 |
| Actual value | 实际价值 |
The output of a plant that is being controlled, i.e. the controlled variable. Not directly accessible by the control system, as it can only be measured by a sensor which may distort the measurement. 受控设备的输出，即受控变量。控制系统不能直接访问，因为它只能由可能会扭曲测量结果的传感器测量。 |
| Interrupted aging | 分段时效 |
Aging at two or more temperatures, by steps, and cooling to room temperature after each step. 分为两个或两个以上的温度时效，按顺序并在每个步骤后冷却至室温。 |
| Compressibility (Unit 1/Pa) | 可压缩性（单位1/Pa） |
A measure of the reduction in volume or increase in density when a substance is subjected to an increase of pressure. It is defined as the reciprocal of the bulk modulus. Liquids and solids are normally considered incompressible, whereas gases are highly compressible. 当物质受到压力增加时体积减少或密度增加的量度。它被定义为体积模量的倒数。液体和固体通常被认为是不可压缩的，而气体是高度可压缩的。 |
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