完整教学课件材料科学与工程基础

1、Fundamentals of Materials Science and EngineeringDepartment of Material ScienceWang YanObjective Introduce fundamental concepts in Material Science and EngineeringItems to be learned: material structure how structure dictates properties how processing can change structurePotential applications: Use

2、materials properly Realize new design opportunities with materials目录第四章 材料的性能 (Material Properties)第三章 材料组成和结构 (Compositions and Structures of Materials )第二章 物质结构基础 (Structure of Matter)第一章 绪论 (Introduction)第五章 材料的制备和成型加工 (Preparation and Manufacturing of Materials)1.1 Defination and Historical Pers

3、pective1.2 Classification of Materials 1.3 Materials Science and Engineering1.4Why Study Materials Science and Engineering1.5 Modern Materials Needs第一章绪 论Chapter 1 Introduction1.1Definition of Materials and Historical Perspective DefinitionThe matter (substance)，not spiritlyWebster “New Internationa

4、l Dictionary（1971）”:The substance or matter of which anything is made or may be made. Webster编者“New International Dictionary（1971年）”中关于材料（Materials）的定义为：材料是指用来制造某些有形物体（如：机械、工具、建材、织物等的整体或部分）的基本物质（如金属、木料、塑料、纤维等） 迈尔新百科全书中材料的含义：材料是从原材料中取得的，为生产半成品、工件、部件和成品的初始物料，如金属、石块、木料、皮革、塑料、纸、天然纤维和化学纤维等等。Materials and

5、 Raw Materials(原材料) Raw Materials: any crude, unfinished, not to obtain products，but produce materials。（having chemical changes）Materials：to obtain products.原料一般不是为获得产品，而是生产材料， 往往伴随化学变化。 材料的特点往往是为获得产品，一般从材料 到产品的转变过程不发生化学变化。1.1Definition of MaterialsDefinitionMaterials and matter： Materials can be ma

6、de of one kind of or more kinds of matters. The same matter can get different types or using materials because of different processing methods. 材料可由一种或多种物质组成。 同一物质由于制备方法或加工方法不同可以得到用途各异、类型不同的材料。Material：材料科学 （工科） 物质科学 （理科） 材料是指具有满足指定工作条件下使用要求的形态和物理性状的物质。1.1Definition of Materials and Historical Persp

7、ective Historical Perspective 材料是人类社会发展的巨大推动力，制造生产工具的物质基础是材料。石器 陶 器铜 器 编 钟铁 器 陶瓷艺术品结束动画图片陶瓷艺术结束动画图片玻璃瓶结束动画图片水果篮结束动画图片门窗玻璃结束动画图片搪瓷茶壶结束动画图片天然花岗岩结束动画图片景泰蓝工艺 蓝地虎头鱼缸结束动画图片中国古代陶器秦始皇兵马俑结束动画图片琉 璃 瓦结束动画图片结束动画图片二、一些典型的高聚物材料塑料布结束动画图片塑料薄膜结束动画图片塑料模仁结束动画图片特种工程塑料结束动画图片特种高聚物材料结束动画图片合成纤维结束动画图片一些典型的高聚物材料聚丙稀短纤维结束动画图片合

8、成橡胶轮胎结束动画图片衣服 纤维结束动画图片塑料的应用塑 钢 窗三、聚合物的应用结束动画图片塑料的应用结束动画图片塑料的应用结束动画图片塑料的应用结束动画图片不锈钢餐具结束动画图片Golf stick结束动画图片破粉碎设备结束动画图片地铁列车结束动画图片吸音吊顶结束动画图片电力陶瓷结束动画图片砂轮结束动画图片钢 塔结束动画图片结束动画图片汽车与高速公路结束动画图片大江截流结束动画图片汽车工业结束动画图片结束动画图片飞机结束动画图片火箭发射结束动画图片 陶瓷艺术品结束动画图片Today The history of materials is the history of human societ

9、y and science technologyThe development of process： Simple Complex Single property Comprehensive property Structural materials Functional materials Single material Composite materials 综合性能结构材料功能材料复合材料1.2 Classification of MaterialsBasicmetals.ceramics. polymers.Engineering materialsCompositesSemicon

10、ductorbiomaterialsMaterialsChemical Makeup State Use Application Field MetalInorganic Nonmetal Material PolymerCompositesGaseous LiquidSolidFunctional StructuralArchitectural、Packagingp5Advanced materialsConcept: Materials that are utilized in high-technology applications. By high technology we mean

11、 a device or product that operates or functions using relatively intricate and sophisticated principles ; examples include electronic equipment, computers, fiber-optic systems, spacecraft, aircraft, and military rocketry.1.3 Materials Science and EngineeringMaterials Science ： involves investigating

12、 the relationships that exist between the structures and properties of materials (研究结构与性能之间的关系)Materials Engineering: designing or engineering the structure of a material to produce a predetermined set of properties, based on these structure-property correlations.(设计材料 结构以产生预定的性能)p2Structure (结构)Con

13、cept：relates to the arrangement of its internal components （内部成分的组织排列）Subatomic On an atomic levelp3Property (性能)Notion： a material trait in terms of the kind and magnitude of response to a specific imposed stimulus. (一种材料对外界刺激反应的类型和程度)Category: mechanical (机械性), electrical（电性）, thermal（热性）, magneti

14、c（磁性）, optical（光学性）, and deteriorative（失效性）p3Mechanical PropertiesNotion: relate deformation to an applied load or force; examples include elastic modulus and strength.Plot of elastic modulus versus temperature for tungsten (钨) , steel (钢), and aluminum (铝)Electrical PropertiesConcept: the stimulus

15、is an electric field, such as electrical conductivity (电导率) and dielectric constant (介电常数).The electrical resistivity versus temperature for copper and three copper-nickel alloys, one of which has been deformed.Note: Electrical conductivity is the reciprocal of the resistivityThermal PropertiesThe t

16、hermal behavior of solids can be represented in terms of heat capacity (热容) and thermal conductivity (导热系数).Thermal conductivity versus composition for copper-zinc alloys.Magnetic PropertiesDemonstrate the response of a material to the application of a magnetic field.Schematic magnetization curves f

17、or soft and hard magnetic materials.Optical PropertiesThe stimulus is electromagnetic or light radiation; index of refraction (折射) and reflectivity (反射) are representative optical properties.Photograph showing the light transmittance of three aluminum oxide specimens. From left to right: single-crys

18、tal material (sapphire), which is transparent (透明); a polycrystalline and full dense (nonporous) material, which is translucent (半透明) and a polycrystalline material the contains approximately 5% porosity, which is opaque(不透明).Deteriorative CharacteristicIndicate the chemical reactivity of materials.

19、Processing (加工) and Performance (表现性能) The structure of a material will depend on how it is processed.A materials performance will be a function of its properties.Materials Science and Engineering Logic1.4 Why Study Materials Science and EngineeringA material problem: One of selecting the right mate

20、rial from the many thousands that are available.Three criteria on which the final decision is normally based: 1. the in-service conditions must be characterized, for these will dictate the properties required of the material.(性能)2. any deterioration of material properties that may occur during servi

21、ce operation.（使用环境）3. economics.（经济）The Materials Selection Process1.5 Modern MaterialsNeeds (self-study) In spite of the tremendous progress that has been made in the discipline of materials science and engineering within the past few years, there still remain technological challenges, including th

22、e development of even more sophisticated and specialized materials, as well as consideration of the environmental impact of materials production. Materials for use in nuclear energy.New high-strength, low-density structural materials, as well as materials with higher-temperature capabilities, for us

23、e in transportation vehicles.Materials for use in the developments that find new, economical sources of energy, and employ the present resources more efficiently.Materials for use in pollution control techniques.The nonrenewable resources, such as polymer and some metals, are gradually becoming depl

24、eted, which necessitates: (1) the discovery of additional reserves, (2) the development of new materials having comparable properties with less adverse environment impact (3) Increase recycling efforts and the development of new recycling technologiesSummaryCourse Goals: Use the right material for t

25、he job. Understand the relation between properties, structure, and processing. Recognize new design opportunities offered by materials selection.Ch.2 Structures of Materials （材料的结构）Content2.1 Introduction (简介)2.2 Fundamental Concepts (基本概念)2.3 Unit cells (单胞)2.4 Metallic crystal Structures (金属的晶体结构)

26、2.5 Density Computations- Metals (金属的密度计算)2.6 Ceramic Crystal Structures (陶瓷的晶体结构)2.7 Density Computations-Ceramics (陶瓷的密度计算)2.8 Silicate Ceramics(硅酸盐陶瓷）2.9 Polymer Structures(聚合物结构)Ch.2 Structures of Materials （材料的结构） The most concerned about materials for people are their properties. The propertie

27、s of materials are related to their composition (成分)、 crystal structures (晶体结构) and the processing (加工).2.1 Introduction (简介)Ch.2 Structures of Materials （材料的结构）Ch.2 Structures of Materials （材料的结构）Eg：Mg (hexagonal close-packed, 六方密堆结构) brittle fewer slip planeAu (face-centered cubic，面心立方结构) ductile

28、more slip planeNoncrystalline (otically transparent 透明) Crystalline (Opaque 不透明, or Translucent 半透明)Ch.2 Structures of Materials （材料的结构）Crystal Structure The different properties between same classification of materials are caused by their Atomic arrangement in the solid state.the manner in which at

29、oms, ions, or molecules are spatially arranged.the manner in which atoms, ions, or molecules are spatially arranged.p31Crystal Structures(晶体结构)2.2 Fundamental Concepts (基本概念) Crystal (晶体) It is solid. The arrangement of atoms in the crystal is periodic. In crystalline structure, the atoms display bo

30、th short-range and long-range order. Eg: metals, many ceramics, and even some polymers.晶 体：原子(团)沿三维空间呈周期性长程有序 (long range order)排列的固体物质（金属，大多陶瓷及一些聚合物） 非晶体：原子(团)无周期性长程有序排列的物质 （包括气体，液体和部分固体） 晶体的性质 熔点确定 有自发形成规则多面体外形的能力 稳定性 （晶体能量最低） 各向异性（物理性质不同） 均匀性（周期小，宏观连续）Crystal Structures(晶体结构) Lattice（点阵,晶格） An in

31、finite array of points in space, in which each point has identical surroundings to all others. A three dimensional array of points coinciding with atom positions (or atomic sphere center).p32点阵： 晶体结构的微观特征 某种结构单元（基元）在三维空间作周期性规则排列基元：原子、分子、离子或原子团 (组成、位形、取向均同)Crystal Structures(晶体结构)Crystal Structures(晶

32、体结构) Crystal Structure（晶体结构） It can be described by associating each lattice point with a group of atoms. 抽象为 基元 几何点 抽象为基元的三维空间周期排列 空间点阵 晶体结构空间点阵结构基元(原子,分子或集团) 点阵反映晶体结构的平移对称 点阵是抽象的几何图形 点阵中每个阵点的周围环境均相同Crystal Structures(晶体结构)2.3 Unit cells (晶胞) The smallest component of the crystal, which when stacke

33、d together with pure translational repetition reproduces the whole crystal. The basic structure unit of the crystal structure and defines the structure by virtue of its geometry and the atom positions within. 晶胞：代表晶体内部结构的基本重复单位（平行六面体） 晶胞的基本要素： A大小和形状 B各原子坐标位置Crystal Structures(晶体结构) Lattice Dimensio

34、ns (晶格参数) a, b and c are the unit cell edge lengths. , , and , are the angles. between b and c between c and a between a and bp49按晶格常数的不同组合可将晶胞分为7种类型，对应7个晶系 (Crystal system)DeterminationX-ray diffraction transmission electron microscope Crystal Structures(晶体结构)2.4 Metallic crystal Structures (金属的晶体结

35、构)Three crystal structures are found in most metals: Face-centered cubic (面心立方); Body-centered cubic (体心立方);Hexagonal-close-packed (六方密堆).p33金属键； 无方向性；原子呈圆球状密堆积Metallic crystal Structures (金属的晶体结构) Face-centered cubic (FCC) crystal structure (面心立方结构) FCC crystal structure has a unit cell of cubic ge

36、ometry, with atoms located at each of the corners and centers of all the cube face.除8个顶点外，每个面心上有一个阵点. a=b=c, =90oCu, Al, Au, Agp33Metallic crystal Structures (金属的晶体结构)Metallic crystal Structures (金属的晶体结构) The relationship between cube edge length a and the atomic radius R : Corner and face positions

37、 are really equivalent (顶角和面心的位置是完全相等的) For FCC structure, a total of four atoms are assigned to a given unit cell (对FCC结构来说,每个单胞有4个完整的原子)81/ 8（角）+ 61/ 2（面）p33Metallic crystal Structures (金属的晶体结构)The length of a face diagonal 4R,The cell edge length aFor FCC, it is a cube. So, there has a right tria

38、ngle on the face:a2+a2=(4R)2Unit cell volume of FCC VC is:Solution: aa4RRMetallic crystal Structures (金属的晶体结构) Coordination number (配位数) For each atom, coordination number is the number of nearest-neighbor or touching atoms.The face atom , has four corner nearest-neighbor , four face atoms from behi

39、nd , and other four equivalent face atoms from the front.Coordination number=4 + 4 + 4 p34Metallic crystal Structures (金属的晶体结构) Atomic packing factor (APF) (原子堆积系数) For FCC structure, APF=0.74Solution:p34Metallic crystal Structures (金属的晶体结构) Body-centered cubic (BCC) crystal structure (体心立方结构) BCC c

40、rystal structure has a unit cell of cubic geometry, with atoms located at eight corners and a single atom at cube center.除8个顶点外，体心上还有一个阵点.a=b=c, =90oCr, a-Fe,W,p34Metallic crystal Structures (金属的晶体结构)BCC crystal structure (体心立方结构) Unit cell length a and atomic radius R are related as: .Each BCC unit

41、 has 2 atoms: single center atom + one atom from the eight corner.Corner and center atom positions are equivalent.The coordination number is 8.Atomic packing factor is 0.68.p34Metallic crystal Structures (金属的晶体结构) Hexagonal close-packed (HCP) crystal structure (六方密堆结构) HCP: The top and bottom faces

42、of the unit cell consist of six atoms that form regular hexagons and surround a single atom in the center. Another plane provides three additional atoms to the unit cell.a=bc,a=g=90o, b=120oCo Cd Mg Zn Tip34Metallic crystal Structures (金属的晶体结构)HCP crystal structure (六方密堆结构) Unit cell length a and at

43、omic radius R are related as:Each HCP unit has 6 atoms: (1/6) 12+(1/2) 2+3Atomic edge length c=1.633a (ideal value). The coordination number is 12.Atomic packing factor is 0.74.结 构 特 征结 构 类 型 体 心 立 方 （bcc） 面 心 立 方 （fcc） 密 排 六 方 （hcp）点 阵 类 型体心立方面心立方简单六方点 阵 常 数aaa，c，c/a =1633最近的原子间距（原子直径）晶胞中原子数6配 位 数8

44、1212致 密 度0.74 典型金属结构晶体学特点 Metallic crystal Structures (金属的晶体结构)2.5 Density Computations- Metals (金属的密度计算):Theoretical density of a metallic solid. n: number of atoms associated with each unit cell.A: Atomic weight.VC: Volume of the unit cell.VA: Avogadros number (6.02x1023 atoms/mol)p37Metallic crys

45、tal Structures (金属的晶体结构)Example: To calculate the theoretical density of Cu. Known parameters:Atomic radius: 0.128nm, FCC crystal structure, Atomic weight A=63.5g/mol.R= 0.128nmn=4Metallic crystal Structures (金属的晶体结构)Measured density: 8.94g/cm3.Solution：组成和结合键1. 组成 广义：除有机物和金属以外。 常见的陶瓷、玻璃、水泥、耐火材料 组分c

46、omponents：硅酸盐类 氧化物类，氮、碳（不含H）。2. 结合键 bonding type 离子键 正负离子、键强度高、紧密堆积、无 方向性， 金属氧化物，氧化镁、氧化铝 共价键 共用电子对、有方向性 如金钢石、 混合键（离子、共价），大多数。 混合键离子键和共价键之间的过渡。 元素电负性的大小，。 2.6 Ceramic Crystal StructuresIt can be described by associating each lattice point with a group of atoms. 晶体结构空间点阵结构基元Crystal Structures2.6 Ceram

47、ic Crystal StructuresCation（阳离子）and Anion（阴离子） Ceramic Crystal StructuresCarbonSilicon and oxygen结构基元(原子)p31 离子键，无方向性。正离子周围配位多个负离子， 离子的堆积受邻近质点异号电荷及化学量比限制 堆积形式决定于正负离子的电荷数和相对大小离子晶体( Ionic Crystal )2.6 Ceramic Crystal Structures Cation（阳离子）and Anion（阴离子） Cations (metallic ions): are positively charged，

48、because they have given up their valence electrons Anions( nonmetallic ions): are negatively charged, because they have accept valence electrons from cations.Examples:Cations: Na (sodium), Ca(calcium) and so onAnions: Cl (chlorine) , F (fluorine) and so on.p38(2) The relative sizes of the cations an

49、d anions. Factors:(1)The magnitude of the electrical charge on each of the component ions. (Electrically neutral)p38CaF2 (calcium fluoride): Ca2+:two positive charges F-: a single negative chargeThe size or ionic radii of the cations and anions (rC and rA) .The coordination numbers and geometriesp40

50、 配位数 CN 正负离子半径比 R/R 负离子配位多面体2 00.155 线 性 配 位30.1550.225 等 边 三 角 形40.2250.414 正 四 面 体60.4140.732 正 八 面 体80.7321.000 立 方 体EXAMPLE PROBLEM 3.4Show that the minimum cation-to-anion radius ratio for the coordination number 3 is 0.155SOLUTIONFor this coordination, the small cation is surrounded by three a

51、nions to form an equilateral triangle as shown belowtriangle ABC; the centers of all four ions are coplanar.This boils down to a relatively simple plane trigonometry problem. Consideration of the right triangle APO makes it clear that the side lengths are related to the anion and cation radii rA and

52、 rC as and Furthermore, the side length ratio AP/AO is a function of the angle as The magnitude of is 30, since line AO bisects the 60 angle BAC. Thus, Or, solving for the cationanion radius ratio,Typical Ceramic Crystal StructureAB type crystal structuresAmBp type crystal structuresAmBnOp type crys

53、tal structuresp41AB type crystal structures (1) Sodium Chloride structure (Rock salt structure)(食盐结构，氯化钠结构）p41Coordination numbercoordination number = 6(for both cations and anions)StructureFCC, Cl- ions at FCC positions; Na+ at the four octahedral sites.The center of the 12 cube edges Other compoun

54、dsMagnesium oxide (MgO) Calcium oxide (CaO),Iron oxide (FeO)Cl- Na+p41（2）Cesium Chloride Structure （氯化铯结构）Coordination numberStructure Simple cubic, Cs+ fill cubic interstitial sites by the Cl- , but not BCCOther compoundsCesium Bromide (CsBr), Cesium Iodide (CsI), Titanium Chloride( TiCl), Ammonium

55、 Chloride(NH4Cl) Coordination number = 8 (for both ion types)Cl- Cs+p41（3） Zinc Blende Structure (ZnS)（硫化锌结构）S(001)p42Coordination number coordination number = 4Structure All corner and face positions are occupied by S anions, Zn fill interior tetrahedral positions. Other compounds Gallium Arsenide

56、(GaAs), - semiconductorsFluorite Structure(CaF2)(氟化钙结构)AB2 type crystal structuresCoordination number coordination number = 8Structure Similar to CsCl, half the center cube positions are occupied by Ca 2+ , F anions locate at the corners.Other compoundsCubic Zirconia (ZrO2), Thorium Oxide (ThO2) Ura

57、nium Oxide (UO2), Cerium Oxide (CeO2)p42Perovskite Structure (CaTiO3)(钙钛矿晶体结构)(a) unit cell structure (b) Ca cation coordination number 12AmBnOp type crystal structuresp43Perovskite Structure (CaTiO3)Structure Ca 2+ cations occupy the cube corner; Ti 4+ cations occupy cube center, O 2- anions occupy

58、 the six face centers of the perovskite unit cell.Other compounds Barium Titanate(BaTiO3) (capacitors for electronic applications )p43 立方晶系 Ca2+ 立方体顶角 配位数12 O2- 面心 配位数6， Ti4+ 体心 配位数6 位于八面体间隙 TiO68-八面体 Ti4+八面体中心 Corundum Structure (-Al2O3 alpha alumina)-Al2O3 structure(a) crystal structure (b) close-

59、packed modelCorundum Structure (-Al2O3 alpha alumina)(刚玉)Structure Oxygen anions pack in a hexagonal arrangement; aluminum cations occupy some of the available positions. Application Most widely ceramic material : spark plugs, refractories, electronic packaging substrates and abrasives.Covalent Stru

60、cturesDiamond Cubic Structure （金刚石结构）p48 共价晶体(Covalent Crystal)： 共价键；有方向性、饱和性， 配位数和方向受限制（配位须成键） 多由非金属元素组成(A族) N族元素共价晶体的配位数为（8N）。 ZnS DiamondStructure Diamond Cubic Structure is a variant of the zinc blende. Carbons occupy both Zn and S positions. Carbon (in its diamond form) are bonded by four coval