机械工程英语句子和选词填空.docx

Part1Unti 11、Metals are elements that generally have good electrical and thermal conductivity.金属就是通常具有良好导电性和导热性的元素。2、Pure metals are elements which come from a particular area of the periodic table.纯金属是在元素周期表中占据特定位置的元素。3、Examples of metal alloys include stainless steel which is an alloy of iron, nickel, and chromium; and gold jewelry which usually contains an alloy of gold and nickel.金属合金的例子有：不锈钢是一种铁、镍、铬的合金，以及金饰品通常含有金镍合金。4、Many metals and alloys have high densities and are used in applications which require a high mass-to-volume ratio. 许多金属和合金具有高密度，因此被用在需要较高质量体积比的场合。5、However, sometimes we can take advantage of plastic deformation. The crumple zones in a car absorb energy by undergoing plastic deformation before they break.然而，有时我们也能利用塑性变形。汽车上压皱的区域在它们断裂前通过经历塑性变形来吸收能量。6、Hence, all the simple and efficient manufacturing techniques used for glass production such as casting and blowing, which involve the molten state, cannot be used for the production of crystalline ceramics. Instead, “sintering” or “firing” is the process typically used. 因此，所有用于玻璃生产的简单有效的诸如浇铸和吹制这些涉及熔化的技术都不能用于由晶体物组成的陶瓷的生产。作为替代，一般采用“烧结”或“焙烧”工艺。7、An example of particle-reinforced composites is an automobile tire which has carbon black particles in a matrix of polyisobutylene elastomeric polymer.微粒加强型复合材料的一个例子是机动车胎，它就是在聚异丁烯人造橡胶聚合物基材中加入了碳黑微粒。Unit 21、 Heat treatment is the operation of heating and cooling a metal in its solid state to change its physical properties.热处理是将金属在固态加热和冷却以改变其物理性能的操作。2、 With the proper heat treatment internal stresses may be removed, grain size reduced, toughness increased, or a hard surface produced on a ductile interior. 使用合适的热处理可以去除内应力、细化晶粒、增加韧性或在柔软材料上覆盖坚硬的表面3、 The key transition described in this diagram is the decomposition of single-phase austenite() to the two-phase ferrite plus carbide structure as temperature drops.在此图中描述的关键转变是单相奥氏体() 随着温度下降分解成两相铁素体加渗碳体组织结构。4、 Tie-line and level-law calculations show that low-carbon ferrite nucleates and grows, leaving the remaining austenite richer in carbon. 在较高温度时，这种材料全部是奥氏体，但随着冷却就进入到铁素体和奥氏体稳定状态的区域。5、 Hypereutectoid steels are steels that contain greater than the eutectoid amount of carbon. 过共析钢是含碳量大于共析量的钢。6、 It should be remembered that the transitions that have been described by the phase diagrams are for equilibrium conditions, which can be approximated by slow cooling. 应该记住由状态图描述的这种转化只适合于通过缓慢冷却的近似平衡条件。7、 Hardening is the process of heating a piece of steel to a temperature within or above its critical range and then cooling it rapidly. 淬火就是把钢件加热到或超过它的临界温度范围，然后使其快速冷却的过程。8、 If the carbon content of the steel is known, the proper temperature to which the steel should be heated may be obtained by reference to the iron-iron carbide phase diagram.如果钢的含碳量已知，钢件合适的加热温度可参考铁碳合金状态图得到。9、 The heavier the section, the longer must be the heating time to achieve uniform results. 截面越厚，加热的时间就要越长才能达到均匀的结果。10、 Steel that has been hardened by rapid quenching is brittle and not suitable for most uses. 快速淬火硬化的钢是硬而易碎的，不适合大多数场合使用。11、 This is usually accomplished by heating the steel too slightly above the critical temperature, holding it there until the temperature of the piece is uniform throughout, and then cooling at a slowly controlled rate so that the temperature of the surface and that of the center of the piece are approximately the same.通常是非常缓慢地将钢加热到临界温度以上，并将其在此温度下保持到工件全部均匀受热，然后以受控的速率慢慢地冷却，这样使得工件表面和内部的温度近似相同。Unit 31、 Casting is a manufacturing process in which molten metal is poured or injected and allowed to solidify in a suitably shaped mold cavity. 铸造是一种将熔化的金属倒入或注入合适的铸模腔并且在其中固化的制造工艺。2、 Castings are parts that are made close to their final dimensions by a casting process. 通过铸造加工，铸件可以做成很接近它们的最终尺寸。3、 The molten material is poured into the pouring cup, which is part of the gating system that supplies the molten material to the mold cavity. 熔化的金属从浇注杯注入型腔，浇注杯是浇注系统向型腔提供熔化金属的部分。4、 Additionally there are extensions to the gating system called vents that provide the path for the built-up gases and the displaced air to vent to the atmosphere.除此之外，还有称为排放口的浇注系统延长段，它为合成气体和置换空气排放到大气提供通道。4、 It can be used to make parts that cannot be produced by normal manufacturing techniques, such as turbine blades that have complex shapes, or airplane parts that have to withstand high temperatures.它还能用于生产一般制造技术无法生产的零件，例如有复杂形状的涡轮叶片或必须耐得住高温的飞机零件。5、 The mold is made by making a pattern using wax or some other material that can be melted away. 制作铸型的型模采用石蜡或其它一些能被融化掉的材料做成。6、 Attention must be paid to mold permeability when using pressure, to allow the air to escape as the pour is done.当使用压力时必须注意渗透性，以便在浇铸的同时让空气逸出。7、 Typical materials that can be cast with this process are aluminum, iron, steel, nickel alloys, copper alloys. Types of parts that can be made using these processes are pump housings, manifolds, and auto brake components.这种工艺所用的典型材料有：铝、铁、钢、镍合金、铜合金。可以采用这些工艺制造的零件类型有泵壳、复式接头和自动刹车部件。Unit 41、 Forging is the process by which metal is heated and is shaped by plastic deformation by suitably applying compressive force. 在锻造过程中先将金属加热，然后施加合适的压力使其塑性变形。2、The feature common to all of them is that, like the hand forging hammer, they utilize the energy of a falling weight to develop the pressure needed for shaping the metal. 就其一般特性而言，都象手工锻锤一样，它们均利用落重能量来产生金属成型所需的压力。3、 One of the basic operations of hammer forging is the elongation of a piece of metal by stretching with hammer blows, causing it to become thinner and longer.锤锻的基本操作之一就是通过锤击使金属伸长，促成其变细变长。4、More important is closed-die forging, very widely used for mass production in industry, in which the metal is shaped by pressing between a pair of forging dies. 更重要的是闭式模锻，在工业上广泛用于规模生产。闭式模锻中金属在一对锻模之间挤压成型。5、Forgings yield parts that have high strength to weight ratio, thus are often used in the design of aircraft frame members. 锻造生产的零件具有较高的强度重量比，所以常被用在飞机结构零件的设计中。Unit 71、The importance of machining processes can be emphasised by the fact that every product we use in our daily life has undergone this process either directly or indirectly. 机加工过程的重要性可通过日常生活使用的每件产品都直接或间接经历这一过程的事实来强调。2、Machining operations are utilized in view of the better surface finish that could be achieved by it compared to other manufacturing operations. 由于机加工能获得比其它制造作业更好的表面光洁度，所以机加工作业具有实用价值。Unit 81、Grinding is a manufacturing process that involves the removal of metal by employing a rotating abrasive wheel. 磨削是通过采用旋转磨轮去除金属的制造工艺。2、 Generally, grinding is considered to be a finishing process that is usually used for obtaining high-dimensional accuracy and better surface finish.一般而言，磨削被认为是一种通常用于获得高尺寸精度和较好表面光洁度的精加工作业。Unit 111、A lathe is a machine tool used primarily for producing surfaces of revolution and flat edges. 车床是主要用于生成旋转表面和平整边缘的机床。Unit 121、Drilling operations can be carried out by using either hand drills or drilling machines. 钻削作业既能采用手钻也能采用钻床来实现。2、Milling is a machining process that is carried out by means of a multiedge rotating tool known as a milling cutter. 铣削是采用被称为铣刀的多刃旋转刀具完成的机加工作业。Part 2Unit 11、 Its inherent speed and storage capacity have made it possible to achieve the advances in image processing, real-time process control, and a multitude of other important functions that are simply too complex and time-consuming to perform manually. 它固有的速度以及存储能力似的它能够在图像处理，实时过程控制以及很多因太复杂太费时而人工无法完成的其他重要功能方面获得进步。2、 The modern digital computer is an electronic machine that can perform mathematical and logical calculations and data processing functions in accordance with a predetermined program of instructions.现在数字计算机是一部能够根据预定的程序来完成数字和逻辑运算以及数据处理功能的电子设备。3、 It is the software that assigns the various functions which the user desires the system to accomplish to the computer. 软件由程序和存储在内存与外存中的指令组成，软件将使用者所要求系统完成的各项功能分配给计算机。4、 These operations include receiving data which enter the computer and deciding how and when the data should be processed. 这些操作包括接收输入电脑的数据和决定数据的处理形式以及处理时间。5、 The capability of the control unit to accomplish these operations is provided by a set of instructions called an executive program which is stored in memory.控制器完成这些操作的能力是由一组存储在存储器中被称作执行程序的指令程序提供的。6、 The logic section can also be used to alter the sequence in which instructions are executed when certain conditions are indicated and to perform other functions, such as editing and masking data for arithmetic operations. 当指出某些条件时逻辑器能够改变程序执行的顺序，也能够完成其他功能，例如为运算操作编辑和屏蔽数据。7、 The binary-coded instructions that computers can understand are called machine language. 这些计算机所能识别的二进制编码叫做机器语言。Unit 21、 Numerical Control (NC) is a form of programmable automation in which the processing equipment is controlled by means of numbers, letters, and other symbols. 数控是程序控制的自动化，在数字控制系统中，设备通过数字，字母和符号来编码。2、 The machine control unit (MCU) consists of the electronics and control hardware that read and interpret the program of instruction and convert it into mechanical actions of the machine tool or other processing equipment.机器控制单元（MUC）由电子和控制硬件组成，机器控制单元可以读出和执行指令程序，可以自动改变加工工具和其他加工设备。3、 There are a number of interpolation schemes that have been developed to deal with the various problems that are encountered in generating a smooth continuous path with a contouring-type NC system. 有一些已形成差补方案来处理数控系统中连续路径和加工系统产生的问题4、 Linear interpolation is the most basic and is used when a straight-line path is to be generated in continuous-path NC.线性差补是最基本的差补方法，用于连续路径的数控系统中。5、 The programmer is required to specify the beginning point and end point of the straight line, and the feed rate that is to be followed along the straight line. 两轴和三轴线性差补路线在实际中有时会分辨出的，但在概念上他们是一样的，程序源要明确指定直线的起点和缺点及沿直线的进给率。6、 A limitation of circular interpolation is that the plane in which the circular arc exists must be a plane defined by two axes of the NC system.圆弧差补的局限性是圆弧路径所在平面是由数控系统中两轴所决定的平面。7、Direct numerical control can be defined as a manufacturing system in which a number of machines are controlled by a computer through direct connection and in real time. 直接数据控制定义为一个制造系统，一定数量的机床有一台计算机通过直接硬件连线实时控制。Unti 31、A program for numerical control consists of a sequence of directions that causes an NC machine to carry out a certain operation, machining being the most commonly used process.数控编程由一系列方向构成，这些方向导致数控车床执行某种操作，加工是最常用的进程。2、 Manual part programming consists first of calculating the dimensional relationships of the tool, workpiece, and worktable, based on the engineering drawings of the part, and manufacturing operations to be performed and their sequence. 手工编程包括根据部分工程图纸首先算出刀具，工件以及工作台的尺寸关系，继而决定执行的操作和工序。3、 Manual programming can be done by someone who is knowledgeable about the particular manufacturing process and is able to understand, read, and change part programs. 手工编程可以由那些具有特定制造工艺知识和能够理解，阅读以及更改部分程序的人来完成。4、 Computer-aided part programming involves special symbolic programming languages that determine th