1、机械英语文部分中英文对照 Ceramics and Glasses陶瓷和玻璃 A ceramic is often broadly defined as any inorganic nonmetallic material By this definition, ceramic materials would also include glasses; however, many materials scientists add the stipulation that “ceramic” must also be crystalline. 陶瓷通常被概括地定义为无机的非金属材料.照此定义，陶
2、瓷材料也应包括玻璃；然而许多材料科学家添加了“陶瓷”必须同时是晶体物组成的约定. A glass is an inorganic nonmetallic material that does not have a crystalline structure. Such materials are said to be amorphous. 玻璃是没有晶体状结构的无机非金属材料.这种材料被称为非结晶质材料.Properties of Ceramics and Glasses Some of the useful properties of ceramics and glasses include
3、 high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance.陶瓷和玻璃的特性 高熔点、低密度、高强度、高刚度、高硬度、高耐磨性和抗腐蚀性是陶瓷和玻璃的一些有用特性.Many ceramics are good electrical and thermal insulators. Some ceramics have special properties: some ceramics are magnetic materi
4、als; some are piezoelectric materials; and a few special ceramics are superconductors at very low temperatures. Ceramics and glasses have one major drawback: they are brittle.许多陶瓷都是电和热的良绝缘体.某些陶瓷还具有一些特殊性能：有些是磁性材料，有些是压电材料，还有些特殊陶瓷在极低温度下是超导体.陶瓷和玻璃都有一个主要的缺点：它们容易破碎. Ceramics are not typically formed from
5、the melt. This is because most ceramics will crack extensively (i.e. form a powder) upon cooling from the liquid state. 陶瓷一般不是由熔化形成的.因为大多数陶瓷在从液态冷却时将会完全破碎(即形成粉末).Hence, all the simple and efficient manufacturing techniques used for glass production such as casting and blowing, which involve the molte
6、n 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.In sintering, ceramic powders are processed into compacted shapes and then heated to temperature
7、s just below the melting point. At such temperatures, the powders react internally to remove porosity and fully dense articles can be obtained.在烧结过程中，陶瓷粉末先挤压成型然后加热到略低于熔点温度.在这样的温度下，粉末内部起反应去除孔隙并得到十分致密的物品. An optical fiber contains three layers: a core made of highly pure glass with a high refractive i
8、ndex for the light to travel, a middle layer of glass with a lower refractive index known as the cladding which protects the core glass from scratches and other surface imperfections, and an out polymer jacket to protect the fiber from damage. 光导纤维有三层：核心由高折射指数高纯光传输玻璃制成，中间层为低折射指数玻璃，是保护核心玻璃表面不被擦伤和完整性不
9、被破坏的所谓覆层，外层是聚合物护套，用于保护光导纤维不受损.In order for the core glass to have a higher refractive index than the cladding, the core glass is doped with a small, controlled amount of an impurity, or dopant, which causes light to travel slower, but does not absorb the light. 为了使核心玻璃有比覆层大的折射指数，在其中掺入微小的、可控数量的能减缓光速而
10、不会吸收光线的杂质或搀杂剂.Because the refractive index of the core glass is greater than that of the cladding, light traveling in the core glass will remain in the core glass due to total internal reflection as long as the light strikes the core/cladding interface at an angle greater than the critical angle. 由于
11、核心玻璃的折射指数比覆层大，只要在全内反射过程中光线照射核心/覆层分界面的角度比临界角大，在核心玻璃中传送的光线将仍保留在核心玻璃中.The total internal reflection phenomenon, as well as the high purity of the core glass, enables light to travel long distances with little loss of intensity.全内反射现象与核心玻璃的高纯度一样，使光线几乎无强度损耗传递长距离成为可能. Composites 复合材料 Composites are formed
12、 from two or more types of materials. Examples include polymer/ceramic and metal/ceramic composites. Composites are used because overall properties of the composites are superior to those of the individual components. 复合材料由两种或更多材料构成.例子有聚合物/陶瓷和金属/陶瓷复合材料.之所以使用复合材料是因为其全面性能优于组成部分单独的性能.For example: polym
13、er/ceramic composites have a greater modulus than the polymer component, but arent as brittle as ceramics. Two types of composites are: fiber-reinforced composites and particle-reinforced composites.例如：聚合物/陶瓷复合材料具有比聚合物成分更大的模量，但又不像陶瓷那样易碎. 复合材料有两种：纤维加强型复合材料和微粒加强型复合材料.Fiber-reinforced Composites Reinfo
14、rcing fibers can be made of metals, ceramics, glasses, or polymers that have been turned into graphite and known as carbon fibers. Fibers increase the modulus of the matrix material. 纤维加强型复合材料 加强纤维可以是金属、陶瓷、玻璃或是已变成石墨的被称为碳纤维的聚合物.纤维能加强基材的模量.The strong covalent bonds along the fibers length give them a
15、very high modulus in this direction because to break or extend the fiber the bonds must also be broken or moved.沿着纤维长度有很强结合力的共价结合在这个方向上给予复合材料很高的模量，因为要损坏或拉伸纤维就必须破坏或移除这种结合. Fibers are difficult to process into composites, making fiber-reinforced composites relatively expensive. 把纤维放入复合材料较困难，这使得制造纤维加强型
16、复合材料相对昂贵.Fiber-reinforced composites are used in some of the most advanced, and therefore most expensive sports equipment, such as a time-trial racing bicycle frame which consists of carbon fibers in a thermoset polymer matrix. 纤维加强型复合材料用于某些最先进也是最昂贵的运动设备，例如计时赛竞赛用自行车骨架就是用含碳纤维的热固塑料基材制成的.Body parts of
17、race cars and some automobiles are composites made of glass fibers (or fiberglass) in a thermoset matrix. 竞赛用汽车和某些机动车的车体部件是由含玻璃纤维(或玻璃丝)的热固塑料基材制成的. Fibers have a very high modulus along their axis, but have a low modulus perpendicular to their axis. Fiber composite manufacturers often rotate layers o
18、f fibers to avoid directional variations in the modulus. 纤维在沿着其轴向有很高的模量，但垂直于其轴向的模量却较低.纤维复合材料的制造者往往旋转纤维层以防模量产生方向变化.Particle-reinforced composites Particles used for reinforcing include ceramics and glasses such as small mineral particles, metal particles such as aluminum, and amorphous materials, inc
19、luding polymers and carbon black.微粒加强型复合材料 用于加强的微粒包含了陶瓷和玻璃之类的矿物微粒，铝之类的金属微粒以及包括聚合物和碳黑的非结晶质微粒. Particles are used to increase the modulus of the matrix, to decrease the permeability of the matrix, to decrease the ductility of the matrix. An example of particle-reinforced composites is an automobile ti
20、re which has carbon black particles in a matrix of polyisobutylene elastomeric polymer. 微粒用于增加基材的模量、减少基材的渗透性和延展性.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. Polymers 聚合材料 A polymer has a repeating structure, usually based on a carbon backbone. The repeating structure results in large chainlike mo
21、lecules. Polymers are useful because they are lightweight, corrosion resistant, easy to process at low temperatures and generally inexpensive. 聚合物具有一般是基于碳链的重复结构.这种重复结构产生链状大分子.由于重量轻、耐腐蚀、容易在较低温度下加工并且通常较便宜，聚合物是很有用的. Some important characteristics of polymers include their size (or molecular weight), so
22、ftening and melting points, crystallinity, and structure. The mechanical properties of polymers generally include low strength and high toughness. Their strength is often improved using reinforced composite structures. 聚合材料具有一些重要特性，包括尺寸(或分子量)、软化及熔化点、结晶度和结构.聚合材料的机械性能一般表现为低强度和高韧性.它们的强度通常可采用加强复合结构来改善.I
23、mportant Characteristics of Polymers Size. Single polymer molecules typically have molecular weights between 10,000 and 1,000,000g/molthat can be more than 2,000 repeating units depending on the polymer structure! 聚合材料的重要特性 尺寸：单个聚合物分子一般分子量为10,000到1,000,000g/mol之间，具体取决于聚合物的结构这可以比2,000个重复单元还多.The mech
24、anical properties of a polymer are significantly affected by the molecular weight, with better engineering properties at higher molecular weights.聚合物的分子量极大地影响其机械性能，分子量越大，工程性能也越好. Thermal transitions. The softening point (glass transition temperature) and the melting point of a polymer will determine
25、 which it will be suitable for applications. These temperatures usually determine the upper limit for which a polymer can be used. 热转换性：聚合物的软化点(玻璃状转化温度)和熔化点决定了它是否适合应用.这些温度通常决定聚合物能否使用的上限.For example, many industrially important polymers have glass transition temperatures near the boiling point of wat
26、er (100, 212), and they are most useful for room temperature applications. Some specially engineered polymers can withstand temperatures as high as 300(572).例如，许多工业上的重要聚合物其玻璃状转化温度接近水的沸点(100, 212)，它们被广泛用于室温下.而某些特别制造的聚合物能经受住高达300(572)的温度. Crystallinity. Polymers can be crystalline or amorphous, but th
27、ey usually have a combination of crystalline and amorphous structures (semi-crystalline). 结晶度：聚合物可以是晶体状的或非结晶质的，但它们通常是晶体状和非结晶质结构的结合物(半晶体). Interchain interactions. The polymer chains can be free to slide past one another (thermo-plastic) or they can be connected to each other with crosslinks (thermos
28、et or elastomer). Thermo-plastics can be reformed and recycled, while thermosets and elastomers are not reworkable. 原子链间的相互作用：聚合物的原子链可以自由地彼此滑动(热可塑性)或通过交键互相连接(热固性或弹性).热可塑性材料可以重新形成和循环使用，而热固性与弹性材料则是不能再使用的. Intrachain structure. The chemical structure of the chains also has a tremendous effect on the pr
29、operties. Depending on the structure the polymer may be hydrophilic or hydrophobic (likes or hates water), stiff or flexible, crystalline or amorphous, reactive or unreactive. 链内结构：原子链的化学结构对性能也有很大影响.根据各自的结构不同，聚合物可以是亲水的或憎水的(喜欢或讨厌水)、硬的或软的、晶体状的或非结晶质的、易起反应的或不易起反应的.第二单元 The understanding of heat treatmen
30、t is embraced by the broader study of metallurgy. Metallurgy is the physics, chemistry, and engineering related to metals from ore extraction to the final product. 对热处理的理解包含于对冶金学较广泛的研究.冶金学是物理学、化学和涉及金属从矿石提炼到最后产物的工程学.Heat treatment is the operation of heating and cooling a metal in its solid state to
31、change its physical properties. According to the procedure used, steel can be hardened to resist cutting action and abrasion, or it can be softened to permit machining. 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.按所采用的步骤，钢可以通过硬化来抵抗切削和磨损，也可以通过软化来允许机加工.With the proper heat treatment internal stresses may be removed, g
32、rain size reduced, toughness increased, or a hard surface produced on a ductile interior. The analysis of the steel must be known because small percentages of certain elements, notably carbon, greatly affect the physical properties.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.因为某些元素(尤其是碳)的微小百分比极大地影响物理性能，所以必须知道对钢的分析. Alloy steel owe their properties to the presence of one or more elements other than carbon, namely nickel, chromium, manganese, molybdenum, tungsten, silicon, vanadium, and copper. Because of their impr
