材料概论复习资料

1、精品精品二影响材料使用的因素Materials behaviorAvailabilityCoseSynthesis and production method (材料的合成与生产方法)Processing techniquesEnvironmental acccptabiliFactors on the propertiet of materials叁成材料的番元素的厚子结构，Atomic structure原子间的相互作用、相互结合，Nature of chemical bench原子或分子在空间的排列分布和运动援津，Atomic ordering原子爱合体的形牝特征。Micros cruc

2、curcProperties of MaterialsMechanical propercics:The bchax-ior of materials deformed bv a secof forces.弹性 Ebsdeiry典性 PbEcicy强度 Strength殛度Hardness韧性 Toughness授劳特性 Fatigue behaviourtT 厝 性 Abrasion resistanceClassification of materials: based on atomic structures and the nature of bondsMetals and cheir

3、 alloys()rganic polymersCeramicsMechanical propcrrics : which reflect the behavior of materials Reformed by a sec of forcesPhysical properties : which describe rhe behavior of materials subjected co the actum of ccmpcrarurc .electric or magnetic fields ,)r light.Chemical properties : which character

4、ize che behavior of material in a reactive environment .PerformancesPropertiesPerformancesPropertiesStructureTypes of materialsmetal it is strong and can be readily formed into practical shapes .its extensive , permanent ducrilicr is an important asset m pcrmicaiig small amounts of yielding to sudde

5、n and severe loads .ceramics and passesChemical stable , siginificandy higher mclring peine. bricdcncsspolymers polymers arc froquendy liveweight Jowcost Jexver strength Jowcr melting poinc and hur chemical rcactrnncomposites it carries along the superior properties of each component, producing a pr

6、oduce chat is superior to either of the components separatelySolids exist in the nature in two principal forms : cn stallinc and amorphousAn clcmcnun, cell of en seal laracc is describedThree secaons a, b, and c.Three angles made byeach two of these sections,a, ,md 丫晶格常数laEcu constaiic /lattice spac

7、ing: a、b、c.crystal s true cure : body-centered cubic structure , face-centered cubic structure , hexagonal close-packed srruccurcthe propcrrics of crystals arc different in various crystallographic directions ,which arc associated with an ordered arrangemenc of atoms in space.Advantages of MetalsStr

8、ongSoft Cutting Machini% ShapingMelting and raringHeat conductiveElectric conductiveIron consist of slag and carbon ,but steel consist of m；uiy clement such as carbon ,silicon .manganese ,iiickcl and so on.Thu types of cast iron ; white cast iron , gray cast iron , alloy cast iron , nodular or ducti

9、le case iron , malleable cast ironAluminumRust resistaatHih reflectivity Can be die cast Bttily machined Good formability Nonmagnetic NontoxicOne-diird the stif&iess of steelOne diird of the weiit of $tedGcxxl thennal and electrical conductivityHigh strength-to-weigjit ratioCan be given a hard surfa

10、ce by anodizing and hard coadxigMost alloys arc weldable rCopper and its alloys : copper , brass and broiizcMagnesiumThe lightest of all structural metalsSpecific gravity.75Magnesium weighs 1.5 rimes less than an equal volume of aluminum and 4 times less than zinc.High strength, sciffiiess, dimensio

11、nd stability,High scrength-to-wcighc rarioAlloys haveRclanvcly high thermal and electrical conducciviacs;Good energy absorption characteristics;Nonmagnetic propertiesMechanical propertiesFor basic types of stresses : teruile, compressive, shear .torsion （拉力，压力，剪切力,扭转力）Strength : the strength of a me

12、tal is its ability to resist changing its shape or size when external forces are applied.Bhstidty: the abibty of a matenal to strain under load and then return to its original shape and size when unloaded.Yield point: yielding or plastic flow occurs in materials when the elastic limit has been excee

13、desicnrc ionCn-sullinc scruccurcHigh thermal and electrical conductivityAbility co be deformed plasncallyMetallic luster （光 泽）or reflectingBody-ccntcrcd cubic : columbium, barium, vanadium, （4可，针 1, 乳）Facc-cciitcrcd cubic : calcium.aluminum.copper, lead jiickcl, goldHexagonal close-packed : zinctita

14、niumtmagncsiumThere arc several ways co protect agaiiisc corrosion. Corrosion can be prevented or lessened byCoatings,Design considerations,Eimronmcncal concrol.Alloying, among ochersCeramic compounds:Can be defined as inorganic compounds made by heating clay or ocher mineral matter to a high temper

15、ature ac which they partially mck and bond cogerher.7Tradiaonal ceramics arc derived and processed from clay or iionday minerals.Most advanced ceramics arc produced from fine trelatively poor powers using new tcchnoloThu property of ceramicsExtreme hardness Heat resistance Corrosion resistance Low e

16、lectrical and dicrmal conductinn Lob rductility （bricdcncss）Pores affect the strength of ceramics m two ways ：they produce stress concentrations. Once the stress reaches a critical level, a crack will form and propagate.pores reduce the cross-sectional areas over which a load can be applied and, con

17、sequendy, lower chc stress chac these maccnals can support.Dcfirurion of glassGlass is ail iiiorgaiuc product of fusion which has cooled to a rigid condition without cnscallizarion.Glass formationGlass fr）rmarion occurs in materials of all chemical types : covalent, ionic , molecular, metallic and h

18、ydrogen bonded maccnals. Glass have been made from element, simple chemical compounds, complex organic molecules , salt mixtures and alloys . there is no particularly advantageous wax of grouping glass forming materials.Composirion of oxide glassMain oxides m glassGlass formers: all oxide whichforms

19、 a glass easily （形成体）B2Q3, Si（）2, P2O5.Ghss modifiers:（修改体）Li2Ot Na2C, K2Q, M）, CaO .Intermediates:（中间体）TiO2, Zn（）, PbO, A12O3Tvm model of asscontinuous random nework modelrandom close packing modelPhysical propertiesDensicy : glass cooled at various rates from above the annealing point will differ in density with the more rapidly cooled glasses having a lower densin,Strength : Thu measured mechanical strength of glass is much lower than the theoretical strength . Mose glasses show a reduction of st