材料结构与性能

1、材料结构与性能,研究生课程,廖 其 龙,Materials Structure and Properties,Office：西5-1-7,1,PPT学习交流,本课程总学时：36学时。 上课时间：718周 课程目的 熟悉材料的基本结构类型；掌握材料组成、制备过程对结构的影响规律；熟悉材料微观结构与材料力学性能的相互关系；了解组成、制备过程及结构对材料物理、化学性能的影响。,2,PPT学习交流,本课程的内容 以无机非金属材料为重点，讨论材料的组成加工结构性能间的相互关系及其影响规律。 主要内容： 材料的分类及结构、性能特点，无机非金属材料晶体的基本结构类型及晶体学基础、玻璃结构及其特点； 材料缺陷

2、的类型、特点及其产生原因； 材料的微观结构表征以及材料组成、制备过程对材料微观结构的影响规律； 材料的力学性能表征以及材料微观结构对材料力学性能的影响； 材料的主要物理性能和化学性能及其影响因素。 教材： Donald R. Askeland Pradeep P. Phul， The Science and Engineering of Materials, 4th ed 吴月华，杨杰，材料的结构与性能，中国科学技术大学出版社，2001,3,PPT学习交流,教学方式：讲解、讨论与自学结合 考核方法：闭卷考试 成绩构成：出勤+讨论+期末考试（闭卷）,4,PPT学习交流,材料的发展 材料结构的三个

3、层次 结构和性能的关系 材料的分类 材料的设计与选用,绪 论,introduction,5,PPT学习交流,Stone age,iron age,Steel age,Advanced materials age,bronze age,Historical Perspective,6,PPT学习交流,7,PPT学习交流,The evolution of materials,8,PPT学习交流,9,PPT学习交流,10,PPT学习交流,THE TOP TEN - 1Periodic Table of Elements,Dmitri Mendeleev(门捷列夫) devises the Perio

4、dic Table of Elements. Introduces the ubiquitous(普遍存在的) reference tool of materials scientists and engineers.,1864,11,PPT学习交流,Egyptians smelt iron (perhaps as a by-product of copper refining) for the first time, using tiny amounts mostly for ornamental or ceremonial purposes. Unlocks the first proce

5、ssing secret of what will become the worlds dominant metallurgical material.,THE TOP TEN 2 Smelting Iron,3500 BC(estimated),熔炼铁,12,PPT学习交流,THE TOP TEN - 3Transistor,John Bardeen, Walter H. Brattain, and William Shockley invent the transistor. Becomes the building block for all modern electronics and

6、 the foundation for microchip and computer technology .,1948,晶体管,13,PPT学习交流,THE TOP TEN - 4Invention of glass,The peoples of northwestern Iran invent glass. Introduces the second great nonmetallic engineering material (following ceramics).,2200 BC (estimated),14,PPT学习交流,THE TOP TEN - 5Optical micros

7、copy,1668 (estimated) Anton van Leeuwenhoek develops optical microscopy capable of magnifications of 200 times and greater. Enables study of the natural world and its structures that are invisible to the unaided eye（肉眼）.,显微镜,15,PPT学习交流,THE TOP TEN - 6Modern concrete,1755 John Smeaton invents modern

8、concrete hydraulic cement（水凝水泥). Introduces the dominant construction material of the modern age.,material composites,16,PPT学习交流,THE TOP TEN - 7Crucible steel,Metal workers in south India develop crucible steel making. Produces “wootz” steel which becomes famous as “Damascus” sword （大马士革剑）steel hund

9、reds of years later, inspiring artisans, blacksmiths, and metallurgists for many generations to come.,300 BC (estimated),坩锅钢（伍兹钢）,17,PPT学习交流,THE TOP TEN - 8Cu extraction （Casting）,In and around modern Turkey, people discover that liquid copper can be extracted from malachite（孔雀石） and azurite（蓝铜矿） an

10、d that the molten metal can be cast into different shapes.,5000 BC(estimated),Introduces extractive metallurgy-the means of unlocking the Earths mineralogical treasures.,提炼铜（铸造）,18,PPT学习交流,THE TOP TEN - 9X-ray diffraction,Max von Laue discovers the diffraction of x-rays by crystals. Creates means to

11、 characterize crystal structures and inspires W.H. Bragg and W.L Bragg in developing the theory of diffraction by crystals, providing insight into the effects of crystal structure on material properties.,1912,19,PPT学习交流,THE TOP TEN - 10Bessemer Process,Henry Bessemer patents a bottom-blown acid proc

12、ess for melting low carbon iron. Ushers in the era of cheap, large tonnage steel, thereby enabling massive progress in transportation, building construction, and general industrialization.,转炉炼钢法,1856,20,PPT学习交流,过程：理解性能和结构的重要环节； 结构：深入理解性能和计算能量的中心环节； 能量: 控制结构的形成和过程的进行。,结构和性能是材料科学的核心问题,材料结构与性能,21,PPT学习

13、交流,材料结构,材料结构,材料组元,排列方式,运动方式,材料的物质组元，如原子、分子和离子,组元间的结合类型，如金属键、离子键、共价键、分子键,电子的运动、原子的热运动,22,PPT学习交流,材料结构在不同层次（不同水平）上的含义 原子排布 最细微水平原子结构 电子构型 化学键合 原子与电子性缺陷 （使材料表现金属、陶瓷和高分子的性能；对材料的电学、 磁学、 热学、光学乃至耐腐蚀性能都有重大影响） 单晶 第二层次原子在空间的排列 多晶 非晶 （晶体结构严重影响到材料的力学性能(强度、塑性、韧性等) 线缺陷 第三层次材料的显微组织形貌 面缺陷 体缺陷 表面缺陷 (缺陷的种类与数量不同导致材料质量

14、与性能悬殊。),23,PPT学习交流,24,PPT学习交流,25,PPT学习交流,Interatomic distance a few A human hair is 50 m Elongated bumps that make up the data track on CD are 0.5 m wide, minimum 0.83 m long, and 125 nm high,26,PPT学习交流,Level of Structure Example of Technologies Atomic Structure Diamond edge of cutting tools Atomic

15、Arrangements: Lead-zirconium-titanate Long-Range Order Pb(Zrx Ti1-x ) or PZT (LRO) gas igniters Atomic Arrangements: Amorphous silica - fiber Short-Range Order optical communications (SRO) industry,Levels of Structure,27,PPT学习交流,Level of Structure Example of Technologies Nanostructure Nano-sized par

16、ticles of iron oxide ferrofluids Microstructure Mechanical strength of metals and alloys Macrostructure Paints for automobiles for corrosion resistance,(Continued),28,PPT学习交流,29,PPT学习交流,研究晶体结构与性能关系时还必须考虑其尺寸的影响。 从原子角度，分为 体材料： 三维方向上尺寸都很大的材料； 低维材料：在一维、二维或三维方向上尺寸很小的材料， 低维材料常具有目前体材料所不具备的性质。 ,结构和性能的关系,30,

17、PPT学习交流,组成-结构-性质-工艺过程之间关系示意图,31,PPT学习交流,Material science is the investigation of the relationship among processing, structure, properties, and performance of materials.,The tetrahedron of materials,32,PPT学习交流,The four components of the discipline of materials science and engineering and their interr

18、elationship. With regard to the relationships of these four components, the structure of a material will depend on how it is processed. Furthermore, a materials performance will be a function of its properties.,性质,性能,33,PPT学习交流,An example of these processing-structure-properties-performanceprinciple

19、s,Photograph of three thin disk specimens of aluminum oxide, which have been placed over a printed page in order to demonstrate their differences in light-transmittance characteristics. The disk on the left is transparent (that is, virtually all light that is reflected from the page passes through i

20、t), whereas the one in the center is translucent (meaning that some of this reflected light is transmitted through the disk). And, the disk on the right is opaquei.e., none of the light passes through it. These differences in optical properties are a consequence of differences in structure of these

21、materials, which have resulted from the way the materials were processed.,translucent,transparent,opaque,34,PPT学习交流,Materials Science and Engineering,Composition means the chemical make-up of a material. Structure means a description of the arrangements of atoms or ions in a material. Synthesis is t

22、he process by which materials are made from naturally occurring or other chemicals. Processing means different ways for shaping materials into useful components or changing their properties.,35,PPT学习交流,36,PPT学习交流,耐腐蚀性,37,PPT学习交流,38,PPT学习交流,39,PPT学习交流,材料的性质是指材料对电、磁、光、热、机械载荷的反应，主要决定于材料的组成与结构。 使用性能是材料在

23、使用状态下表现的行为，它与材料设计、工程环境密切相关。 合成与制备过程包括传统的冶炼、铸锭、制粉、压力加工、焊接等，也包括新发展的真空溅射、气相沉积等新工艺，使人工合成材料如超晶格、薄膜材料成为可能。,40,PPT学习交流,Properties,Properties are the way the material responds to the environment and external forces. Mechanical properties response to mechanical forces, strength, etc. Electrical and magnetic

24、properties - response electrical and magnetic fields, conductivity, etc. Thermal properties are related to transmission of heat and heat capacity. Optical properties include to absorption, transmission and scattering of light. Chemical stability in contact with the environment - corrosion resistance

25、.,41,PPT学习交流,Application of the tetrahedron of materials science and engineering to ceramic superconductors. Note that the microstructure-synthesis and processing-composition are all interconnected and affect the performance-to- cost ratio,42,PPT学习交流,Application of the tetrahedron of materials scien

26、ce and engineering to sheet steels for automotive chassis（底盘）. Note that the microstructure-synthesis and processing-composition are all interconnected and affect the performance-to-cost ratio,43,PPT学习交流,Application of the tetrahedron of materials science and engineering to semiconducting polymers f

27、or microelectronics,44,PPT学习交流,A better understanding of structure-composition-properties relations has lead to a remarkable progress in properties of materials. Example is the dramatic progress in the strength to density ratio of materials, that resulted in a wide variety of new products, from dent

28、al materials to tennis racquets.,aramid fibre：芳香尼龙纤维,45,PPT学习交流,材料的性能是一种参量，用于表征材料在给定条件下的行为。材料的性能只有在外界条件下才能表现出来。外界条件是指温度、压力、载荷、电场、磁场、化学介质等。,46,PPT学习交流,材料按化学组成（或基本组成）分类 根据材料的性能分类 材料按服役的领域来分类 材料按结晶状态分类 材料按材料的尺寸分类,材料分类,47,PPT学习交流,A familiar item that is fabricated from three different material types is

29、the beverage container. Beverages are marketed in aluminum (metal) cans, glass (ceramic) bottles， and plastic (polymer) bottles.,aluminum cans,glass bottles,plastic bottles,48,PPT学习交流,按化学组成（或基本组成）分类： 材料的四大家族,A. 金属材料 B. 无机非金属材料 C. 高分子材料（聚合物） D. 复合材料,49,PPT学习交流,Classification of Materials according to

30、 the way the atoms are bound together,Metals and Alloys：valence electrons are detached from atoms, and spread in an electron sea that glues the ions together. Strong, ductile, conduct electricity and heat well, are shiny if polished. Ceramics: compounds between metallic and nonmetallic elements, ins

31、ulative to the passage of electricity and heat, including clay(陶土), cement and glass. Polymers ：are bound by covalent forces and also by weak van der Waals forces, and usually based on C and H. They decompose at moderate temperatures (100 400 C), and are lightweight. Examples: plastics rubber. Semic

32、onductors：the bonding is covalent (electrons are shared between atoms). Their electrical properties depend strongly on minute proportions of contaminants. Examples: Si, Ge, GaAs. Composite Materials: consist of more than one material type and usually have better properties than its components in som

33、e aspect.,50,PPT学习交流,Metals,Familiar objects that are made of metals and metal alloys: (from left to right) silverware (fork and knife), scissors, coins, a gear, a wedding ring, and a nut and bolt.,Several uses of steel and pressed aluminum.,51,PPT学习交流,Ceramics,Common objects that are made of cerami

34、c materials: scissors, a china tea cup, a building brick, a floor tile, and a glass vase.,52,PPT学习交流,Ceramics,Examples of ceramic materials ranging from household to high performance combustion engines which utilize both metals and ceramics.,53,PPT学习交流,Several common objects that are made of polymer

35、ic materials: plastic tableware (spoon, fork, and knife), billiard balls, a bicycle helmet, two dice, a lawnmower wheel (plastic hub and rubber tire), and a plastic milk carton.,Polymers,54,PPT学习交流,Polymers,Polymers include “Plastics” and rubber materials,55,PPT学习交流,Composites,Polymer composite mate

36、rials: reinforcing glass fibers in a polymer matrix.,56,PPT学习交流,The world of materials,57,PPT学习交流,Semiconductors,Micro-Electrical-Mechanical Systems,Si wafer for computer chip devices.,58,PPT学习交流,Types of solids,Amorphous only short range order; no periodicity. melting point over a large range. Powd

37、er x-ray diffraction has broad peaks glasses, polymers and supercooled liquids,Crystalline characterized by 3-dimensional periodicity (in perfect crystals) Powder x-ray diffraction has sharp peaks sharp melting points (in general) distinct morphology; well developed faces,59,PPT学习交流,Structure and Pr

38、operties of Materials,Solid-state and Crystalline structure Amorphous vs poly-crystalline vs single crystal What properties depend on solid-state structure MECHANICAL PROPERTIES ELECTRONIC PROPERTIES,60,PPT学习交流,Types of solids,Liquid crystals characterized by 1- or 2-dimensional order rod- or disc-l

39、ike molecules,61,PPT学习交流,Types of solids,Polymers only short range order; no periodicity. melting point over a large range.,62,PPT学习交流,Types of solids,Quasicrystals（准晶） e.g. rapidly cooled alloys both short- and long-range order but incompatible with translational periodicity (e.g. 5-dimensional sym

40、metry seen in diffraction patterns),63,PPT学习交流,Types of solids,Nano-crystals (quantum dots) solids of dimensions 1-100nm,Nanocrystal of RuS2,Semiconducting Nanocrystal,64,PPT学习交流,Nano-crystals (quantum dots),Nano-diamond Fullerenes, or buckyballs, are soccer-ball-shaped molecules named for R. Buckmi

41、nster Fuller, whose popular geodesic dome is structurally similar to a fullerene molecule. In first-principles simulations of nano-diamond, (a) the surface of a 1.4-nanometer nano-diamond with 275 atoms spontaneously rearranges itself into (b) a fullerene at about 300 kelvins. These carbon clusters

42、have a diamond core (yellow) and a fullerene-like reconstructed surface (red). (c) A classic 60-atom carbon buckyball.,富勒烯（巴基球、足球烯）,65,PPT学习交流,Representative examples, applications, and properties for each category of materials,Example of Applications Properties Metals and Alloys Gray cast iron Auto

43、mobile engine blocks Castable, machinable, vibration damping Ceramics and Glasses SiO2-Na2O-CaO Window glass Optically transparent, thermally insulating Polymers Polyethylene Food packaging Easily formed into thin, （聚乙烯） flexible, airtight film,66,PPT学习交流,Example of Applications Properties Semicondu

44、ctors Silicon Transistors and integrated Unique electrical circuits behavior Composites Carbide cutting tools for High hardness, yet Tungsten carbide machining good shock resistance -cobalt (WC-Co),Continued,硬质合金刀具,67,PPT学习交流,Representative strengths of various categories of materials,68,PPT学习交流,A s

45、ection through a jet engine. The forward compression section operates at low to medium temperatures, and titanium parts are often used. The rear combustion section operates at high temperatures and nickel-based superalloys are required. The outside shell experiences low temperatures, and aluminum an

46、d composites are satisfactory.,A variety of complex ceramic components, including impellers and blades, which allow turbine engines to operate more efficiently at higher temperatures.,Ti,镍基超耐热合金,铝及复合材料,涡轮发动机的陶瓷叶轮及叶片,69,PPT学习交流,Schematic of a X-33 plane prototype. Notice the use of different material

47、s for different parts.,70,PPT学习交流,Polymerization occurs when small molecules, represented by the circles, combine to produce larger molecules, or polymers. The polymer molecules can have a structure that consists of many chains that are entangled but not connected (thermoplastics) or can form three-

48、dimensional networks in which chains are cross-linked (thermosets),热固塑料,热塑性塑料,not connected,cross-linked,71,PPT学习交流,Polymers are used in a variety of electronic devices, including these computer dip switches, where moisture resistance and low conductivity are required.,Integrated circuits for comput

49、ers and other electronic devices rely on the unique electrical behavior of semiconducting materials.,The X-wing for advanced helicopters relies on a material composed of a carbon-fiber- reinforced polymer.,碳纤维增强聚合物机翼,72,PPT学习交流,根据材料的性能分类,根据材料在外场作用下其性质或性能对外场的响应不同，材料可分为结构材料和功能材料。,73,PPT学习交流,Functional

50、 Classification of Materials,Aerospace Biomedical Electronic Materials Energy Technology and Environmental Technology Magnetic Materials Photonic or Optical Materials Smart Materials Structural Materials,74,PPT学习交流,Functional classification of materials. Notice that metals, plastics, and ceramics oc

51、cur in different categories. A limited number of examples in each category is provided,75,PPT学习交流,Classification of Materials-Based on Structure,Crystalline material is a material comprised of one or many crystals. In each crystal, atoms or ions show a long-range periodic arrangement. Single crystal

52、 is a crystalline material that is made of only one crystal (there are no grain boundaries). Grains are the crystals in a polycrystalline material. Polycrystalline material is a material comprised of many crystals (as opposed to a single-crystal material that has only one crystal). Grain boundaries

53、are regions between grains of a polycrystalline material.,76,PPT学习交流,Environmental and Other Effects,Effects of following factors must be accounted for in design to ensure that components do not fail unexpectedly: Temperature Corrosion Fatigue Strain Rate （应变率）,77,PPT学习交流,Increasing temperature norm

54、ally reduces the strength of a material. Polymers are suitable only at low temperatures. Some composites, special alloys, and ceramics, have excellent properties at high temperatures,78,PPT学习交流,Skin operating temperatures for aircraft have increased with the development of improved materials.,79,PPT

55、学习交流,Materials Design and Selection,Different materials exhibit different crystal structures and resultant Properties,材料的设计与选用,80,PPT学习交流,材料设计的工作思路,81,PPT学习交流,Materials Design and Selection,Density is mass per unit volume of a material, usually expressed in units of g/cm3 or lb/in.3 Strength-to-weig

56、ht ratio is the strength of a material divided by its density; materials with a high strength-to-weight ratio are strong but lightweight.,82,PPT学习交流,碳/环氧复合材料,83,PPT学习交流,Material Selection,展延性,84,PPT学习交流,Basic material properties,85,PPT学习交流,Mechanical properties illustrated,stiffness：刚度，抵抗变形的能力。 hard

57、ness：硬度，抵抗外物刺入或切削的能力。 toughness：韧性,86,PPT学习交流,Materials information for design,The goal of design:“To create products that perform their function effectively, safely, at acceptable cost” What do we need to know about materials to do this? More than just test data.,87,PPT学习交流,The nature of material data,88,PPT学习交流,Structured data for ABS,(ABS-丙烯腈-丁二烯-苯乙烯),89,PPT学习交流,Unstructured