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1、1Chapter 1 An Overview第一章概述1.1 Introduction1.1 介绍Materials are the matter of the universe. These substances have properties that make them useful in structures, machines, devices, products, and systems. The term properties describe behavior of materials when subjected to some external force or condi
2、tion. For example, the tensile strength of a metal is a measure of the materials resistance to a pulling force. The Family of Materials consists of four main groups of materials: Metals (e.g., steel), Polymers (e.g., plastics), Ceramics (e.g., porcelain), and Composites (e.g., glass-reinforced plast
3、ics). The materials in each group have similar properties and/or structures, as will be described later.材料是宇宙的物质。这些物质的特性使其有用的结构、机器设备、产品和系统。这个术语属性描述材料的行为时,受到一些外部力量或状态。例如,抗拉强度的金属是测量的材料抵抗了拉力。这个家庭的材料由四个主要群体的材料:金属(如钢)、高分子材料(例如:塑料)、陶瓷(如瓷),复合材料(例如,增强塑料)。每一组的材料有相似的性质和/或建筑物,如稍后会提到。Engineering materials is a
4、term often used loosely to define most materials that go into products and systems. A telephone is a product that would be part of a telephone system composed of many telephones, wires, fiber optics, switches, computers, and so on. Engineering materials can also have a more specific meaning that ref
5、ers to materials whose structure has been designed to develop specific properties for a given application.工程材料是一种常用的松散定义最材料,进入产品和系统。电话是一种产品,将部分电话系统由许多电话、电线、光纤、开关、电脑等。工程材料也可以有更多的特定含义是指材料的结构已经被设计来发展特性对于一个给定的应用。Engineering plastics such as polycarbonates and acetals could replace more conventional engi
6、neering materials such as steel and wood because their properties are competitive for structural components such as piping, cams, and gears. On the other hand, general-purpose plastics, such as polystyrene and vinyls, do not possess the properties to carry heavy loads but serve as packaging, upholst
7、ery, and so on.工程塑料,如 polycarbonates 缩醛可以代替常规,工程材料,如钢材和木材,因为它们的性质有竞争力的结构元件,如管道、视角、齿轮。另一方面,通用型塑料制品,如聚苯乙烯、乙烯基、不具有携带重物,但作为包装、室内装潢,等等。2The field of materials engineering “deals with the synthesis and use of knowledge (structure, properties, processing, and behavior) in order to develop, prepare, modify,
8、 and apply materials to specific needs“. Materials engineers have become very much in demand as we seek to improve the efficiency of products.这个领域的材料工程”涉及的合成和使用知识结构、性能、加工、行为)为了发展、准备、修改和申请材料的具体需求”。物料工程师已经成为需求量很大寻求提高效率的产品。Materials science and engineering (MSE) has become a major field of study, one c
9、ritical to many other fields. As defined by a National Academy of Sciences study, MSE involves the generation and application of knowledge relating the composition, structure, and processing of materials to their properties and uses. The “science“ focuses on discovering the nature of materials, whic
10、h in turn leads to theories or descriptions that explain how structure relates to composition, properties, and behavior. The “engineering,“ on the other hand, deals with use of the science in order to develop, prepare, modify, and apply materials to meet specific needs. The field is often considered
11、 an engineering science because of its applied nature. Materials science and engineering is interdisciplinary or multidisciplinary, embracing areas such as metallurgy, ceramics, solid-state physics, and polymer chemistry.材料科学与工程专业(MSE)已成为一个主要的研究领域,对其他许多领域的一个关键。定义一个国家科学院的一代,MSE 涉及研究和应用的相关知识的组成、结构、加工材
12、料性能和用途。“科学”的自然材料的发现,这就导致了理论或描述解释结构与组成、性质和行为。“工程”,另一方面,利用科学为发展,制定、修改、申请材料以满足特定需求。这个领域通常是被视为一种工程应用科学,因为它的本质。材料科学与工程学科交叉或语系,冶金、建材、陶瓷等领域,固态物理、聚合物化学。Many new processes have evolved for the manufacture of engineering materials. Through these processes, coupled with the design of engineering materials, we
13、now enjoy the benefits of superior engineering materials.We current have available for potential use in engineering structures and electronic devices about 45,000 different metallic alloys, of the order of 15,000 different polymers, and hundreds, if not thousands, of other materials that fall in the
14、 categories of wood, ceramics, fabrics, and semiconductors. An automobile alone contains several hundred different materials. A 1986 Mercedes-Benz contains 67 wt% cast iron and steel, 12 wt% fabrics, 12 wt% polymers, and 4 wt% aluminum alloys, the balance being composed of glass and other nonferrous
15、 alloys. For a 1996 Mercedes-Benz, a span of only 10 years, iron and steel use fell to 62 wt%, while polymers and aluminum alloy content increased to 18 and 6 wt%, respectively. Throughout all industries, the trend to more polymer use is evident. As you are probably aware, polymers have replaced met
16、als in many household functions. It is thus not only the current materials available with which we must be concerned in the material selection process but also those on the horizon, particularly the new developments in the fast-growing technologies. Frequently, such material 3developments can be transferred to the older, more mature industries. Figure 1-1 depicts a maturity curve for a variety of materials. This curve is, to a certain degree, based on projected use and should be considered in t