专业外语考试资料整理bete 10Word格式.docx

1、 it may have to be readily recyclable; and its cost and availability may be of critical importance.我们不能在这里讨论这些深奥的特性。在合金材料被采用和应用于工程实际之前，掌握其结构强度和它的综合性质就够了。举例来说，它可以强度很高，并且有好的耐磨性；它可以被例如拉伸加工，机械加工，或焊接等特殊工艺来加工出来；它可以被循环利用；它的成本和实用性是首要的。3.Put the following into Chinese.Aluminum 铝；copper 铜；nickel 镍； titanium 钛

2、；structure strength 结构强度；deep drawing 深拉；4.Put the following into English.定义definition 力 force 轴 axle 非金属nonmental 结构 structure 载荷 load 用途 application 性质 property4.Put the following sentences into English.金属和非金属的差异一般很难界定。The distinction between a metal and a nonmetal is not always clear-cut.即使绝对纯金属可

3、以生产出来，工程师们对它并不特别感兴趣。Engineers would not be particularly interested in such a metal even if it were to be produced。在50种左右的金属元素里，工程实践中只有少数金属被大量生产和使用。Of the 50 or so metallic elements, only a few are produced and used in large quantities in engineering practice.Unit 2 Selection of Construction Material

4、s 3.Translate the 11th and 13th paragraph into Chinese.It is not determined by hardness alone, but by the toughness, microstructure, chemical composition, and tendency of a metal to harden under cold work. In the misleading expression “too hard to machine”, the word “hard” is usually meant to be syn

5、onymous with “difficult”. Many times a material is actually too soft to machine readily. Softness and toughness may cause the metal to tear and flow ahead of the cutting tool rather than cut cleanly. Metal that are inherently soft and tough are sometimes alloyed to improve their machinability at som

6、e sacrifice in ductility. Examples are use of lead in brass and of sulfur in steel. 加工性不仅仅只由硬度决定，它还由韧性，微观结构，化学成分和在冷加工下金属所呈现的硬化特性所决定。在容易混淆的表示“难加工”中，“hard”与“difficult”同义。许多时候，因为材料过软而难于稳定加工。材料柔软性和韧性能够产生金属撕裂，使金属在完成切削前流动至刀具前端。柔软的金属往往会被加入合金从而牺牲它的延展性来提高加工性能。如黄铜中加入铅钢中加入硫磺。In the machining of metal, the meta

7、l being cut, the cutting tool, the coolant, the process and type of machine tool, and the cutting conditions all influence the results. By changing any one of these factors, different results will be obtained. The criterion upon which the ratings listed are based is the relative volume of various ma

8、terials that may be removed by turning under fixed conditions to produce an arbitrary fixed amount of tool wear.在对金属进行加工时，被切削的金属，切削刀具，冷却液，使用的机床的种类，切削条件均影响着切削效果。改变任何一种均会产生不同的切削效果。切削效果评定的准则是：车削时在固定的切削条件下产生一定量的刀具磨损时，被加工试件相应的材料去除量。4.Put the following into Chinese.Hardenability 淬硬性，可淬化性；machinability 机加工

9、性；cold drawn 冷拔，冷拉；Steel sheet 钢片，薄钢板； percent reduction in area 断面收缩率；endurance limit 疲劳极限Rolled-steel shapes 型钢；corrosion resistance 抗腐蚀性；rupture 断裂；5.Put the following into English.低碳钢 low-carbon steel 高强度钢 high-strength steel 热处理 heat treatment 屈服强度 yield strength 弹性模量 elasticity modulus 伸长率 elo

10、ngation 韧性 tenacity 内应力 Internal stressUnit 3 Mechanical Properties of Materials材料的机械性能3.Translate the 5th and 6th paragraph into Chinese.This is a curve plotted between the stress along the Y-axis（ordinate） and the strain along the X-axis（abscissa） in a tensile test. A material tends to change or c

11、hanges its dimensions when it is loaded, depending upon the magnitude of the load. When the load is removed it can be seen that the deformation disappear s. For many materials this occurs up to a certain value of the stress called the elastic limit. This is depicted by the straight line relationship

12、 and a small deviation thereafter, in the stress-strain curve. 如图所示为在拉伸试验中沿着X轴（横轴）的应变和沿着Y轴（纵轴）的应力之间的关系曲线。材料在加载时，随着载荷大小的变化，尺寸会发生改变。当卸载时，变形消失。对于许多材料来说，上述情况发生的应力极限值称为弹性极限。在应力-应变曲线中，直线关系和随后的小小的弯曲描述了上述的加载和卸载。 Within the elastic range, the limiting value of the stress up to which the stress and strain are

13、 proportional, is called the limit of proportionality. In this region, the metal obeys Hookes law, which states that the stress is proportional to strain in the elastic range of loading （the material completely regains its original dimensions after the load is removed）. In the actual plotting of the

14、 curve, the proportionality limit is obtained at a slightly lower value of the load than the elastic limit. This may be attributed to the time-lag in the regaining of the original dimensions of the material. This effect is very frequently noticed in some no-ferrous metals.在弹性范围内，应力应变成比例的应力极限值称为比例极限。

15、在这个区域中，金属服从胡克定律阐述了在加载的弹性范围内，应力和应变成比例关系（材料在卸载后，能够完全回复它原来的尺寸）。在曲线的实际绘制中，比例极限值要稍微比弹性极限值低。这可能是由于材料回复原尺寸需要的时间延迟。这种现象在一些有色金属中常常出现。 4.Put the following into Chinese.by reference to the text.Non-ferrous 有色金属；stress-strain curve 应力应变曲线；yield point 屈服点；percentage elongation 伸长率；necking 颈缩；sensitivity 灵敏度；应变硬化

16、 strain hardening 横截面 cross section 断面收缩率percent reduction in area比例极限 proportional limit 屈服极限 yield limit 延性 Ductility 机械性质Mechanical Properties 用除 usein addition to6.Put the following sentences into English.当承载时，材料将发生变形，变形量取决于载荷的大小。A material tends to change or changes its dimensions when it is lo

17、aded, depending upon the magnitude of the load.在弹性范围内，载荷被卸除后，试件的变形消失。In the elastic range of loading, the material completely regains its original dimensions after the load is removed）逻辑上，一旦超过弹性极限，金属将开始屈服，并且在不断增加应力值的情况下。也会最终断裂。Logically speaking, once the elastic limit is exceeded, the metal should

18、starts to yield, and finally break, without any increase in the value of stress.Unit 5 Design of Machine and Machine elements机器和机器零件的设计3.Translate the 8th paragraph into Chinese.If a critical part of a machine fails, the whole machine must be shut down until a repair is made. Thus, when designing a

19、new machine, it is extremely important that critical parts be made strong enough to prevent failure. The designer should determine as precisely as possible the nature, magnitude, direction and point of application of all forces. Machine design is mot, however, an exact science and it is, therefore,

20、rarely possible to determine exactly all the applied forces. In addition, different samples of a specified material will exhibit somewhat different abilities to resist loads, temperatures and other environment conditions. In spite of this, design calculations based on appropriate assumptions are inv

21、aluable in the proper design of machine.如果一个机器的关键件损坏，整个机器必须关闭，直到修理好为止。设计一台新机器时，关键件具有足够的抵抗破坏的能力是非常重要的。设计者应尽可能准确地确定所有的性质、大小、方向及作用点。机器设计不是这样，但精确的科学是这样，因此很难准确地确定所有力。另外，一种特殊材料的不同样本会显现出不同的性能，像抗负载、温度和其他外部条件。尽管如此，在机械设计中给予合理综合的设计计算是非常有用的。Kinematic elements 运动元素； external appearance 外观； sound judgment 正确的判断；F

22、atigue strength 疲劳强度；environmental damage 环境破坏；ductile or brittle 延展性或脆性；Blow out 爆胎；interference fit joints 过盈配合；5.Put the following sentences into English.设计计算的目的是预测零件的应力和变形，从而保证零件能安全承受施加的载荷，并保证在预期寿命内安全。The purpose of the design calculations is, of course, to attempt to predict the stress or defor

23、mation in the part in order that it may sagely carry the loads, which will be imposed on it, and that it may last for the expected life of the machine.交变动载荷通常比静载荷更危险，必须考虑疲劳强度。Generally speaking, dynamic loads with direction reversals cause greater difficulties than static loads and, therefore, fatig

24、ue strength must be considered.Unit 7 Shaper, Planer,Milling and Grinding Machines 牛头刨床，龙门刨床，铣床和磨床3.Translate the 4th and 7th paragraph into Chinese.Cutting speeds are slow on the planer because of the workpiece size and type of cutting tool being used. In order to increase the production of the pla

25、ner, multiple tooling stations are employed. Two tooling stations are located on the overhead cross rails, with usually one tooling station on the vertical supports. Another method of increasing production on the planer is to mount a number of workpieces on the table at the same time. This method is

26、 only feasible when the workpieces require the same cut and are relatively small in size. The planer size is designated by the maximum workpiece capacity of the machine. The height, width, and length of the workpiece that can be accommodated on the planers worktable varies with the type of planer.因为

27、工件尺寸和使用刀具类型的关系，龙门刨床的切削速度比较慢。为了提高龙门刨床的生产效率会使用多个动力头来进行切削。在上方交叉导轨上会安装两个刀架，在垂直导轨上会安装一个。另一种提高龙门刨生产率的方法是在工作台上同时装夹多个零件。只有工件具有相同的切削要求和工件尺寸较小时才能使用这种方法。龙门刨的规格是由机床所能加工零件的最大尺寸决定的。能够加工零件的长、宽、高随着龙门刨型号的不同而不同。Grinding machines utilize abrasive grains, bonded into various shapes and sizes of wheels and belts to be used as the cutting agent. Grinding operations are used to impart a high-quality surface finish on the workpiece. In addition, the dimensional accuracy of the workpiece is improved since tolerances of 0.00001 in.