材料概论复习资料

材料概论复习资料材料概论复习资料材料概论复习资料V:1.0精细整理，仅供参考材料概论复习资料日期：20xx年X月影响材料使用的因素MaterialsbehaviorAvailabilityCostSynthesisandproductionmethod（材料的合成与生产方法）ProcessingtechniquesEnvironmentalacceptabilityFactorsonthepropertiesofmaterials组成材料的各元素的原子结构，Atomicstructure原子间的相互作用、相互结合，Natureofchemicalbonds原子或分子在空间的排列分布和运动规律,Atomicordering原子集合体的形貌特征。MicrostructurePropertiesofMaterialsMechanicalproperties:Thebehaviorofmaterialsdeformedbyasetofforces.弹性Elasticity塑性Plasticity强度Strength硬度Hardness韧性Toughness疲劳特性Fatiguebehaviour耐磨性AbrasionresistanceClassificationofmaterials:basedonatomicstructuresandthenatureofbondsMetalsandtheiralloysOrganicpolymersCeramicsMechanicalproperties:whichreflectthebehaviorofmaterials,deformedbyasetofforcesPhysicalproperties:whichdescribethebehaviorofmaterialssubjectedtotheactionoftemperature,electricormagneticfields,orlight.Chemicalproperties:whichcharacterizethebehaviorofmaterialinareactiveenvironment.Typesofmaterials1metalitisstrongandcanbereadilyformedintopracticalshapes.itsextensive,permanentductilityisanimportantassetinpermittingsmallamountsofyieldingtosuddenandsevereloads.2ceramicsandglassesChemicalstable,siginificantlyhighermeltingpoint,brittleness3polymerspolymersarefrequentlylightweight,lowcost,lowerstrength,lowermeltingpointandhigherchemicalreactivity4compositesitcarriesalongthesuperiorpropertiesofeachcomponent,producingaproductthatissuperiortoeitherofthecomponentsseparatelySolidsexistinthenatureintwoprincipalforms:crystallineandamorphousAnelementarycellofcrystallatticeisdescribedThreesectionsa,b,andc,Threeanglesmadebyeachtwoofthesesections,α,β,andγ.晶格常数latticeconstant/latticespacing:a、b、c.crystalstructure:body-centeredcubicstructure,face-centeredcubicstructure,hexagonalclose-packedstructurethepropertiesofcrystalsaredifferentinvariouscrystallographicdirections,whichareassociatedwithanorderedarrangementofatomsinspace.AdvantagesofMetalsStrongSoft:Cutting,Machining,ShapingMeltingandcastingHeatconductiveElectricconductiveLight-ReflectiveIronconsistofslagandcarbon,butsteelconsistofmanyelementsuchascarbon,silicon,manganese,nickelandsoon.Thetypesofcastiron；whitecastiron,graycastiron,alloycastiron,nodularorductilecastiron,malleablecastironAluminumRustresistantHighreflectivityCanbediecastEasilymachinedGoodformabilityNonmagneticNontoxicOne-thirdthestiffnessofsteelOnethirdoftheweightofsteelGoodthermalandelectricalconductivityHighstrength-to-weightratioCanbegivenahardsurfacebyanodizingandhardcoatingMostalloysareweldableCopperanditsalloys:copper,brassandbronzeMagnesiumThelightestofallstructuralmetalsSpecificgravity:Magnesiumweighstimeslessthananequalvolumeofaluminumand4timeslessthanzinc.Highstrength,stiffness,dimensionalstability,Highstrength-to-weightratioAlloyshaveRelativelyhighthermalandelectricalconductivities;Goodenergyabsorptioncharacteristics;NonmagneticpropertiesMechanicalpropertiesForbasictypesofstresses:tensile,compressive,shear,torsion(拉力，压力，剪切力，扭转力)Strength:thestrengthofametalisitsabilitytoresistchangingitsshapeorsizewhenexternalforcesareapplied.Elasticity:theabilityofamaterialtostrainunderloadandthenreturntoitsoriginalshapeandsizewhenunloaded.Yieldpoint:yieldingorplasticflowoccursinmaterialswhentheelasticlimithasbeenexceeded.Plasticity:metalsundergoplasticflowwhenstressedatorbeyondtheirelasticlimits.Brittleness:amaterialthatwillnotdeformplasticallyissaidtobebrittle.Stiffness:stiffnessisexpressedbythemodulusofelasticity.Ductility:thepropertythatallowsametaltodeformpermanentlywhenloadedintension.Astemperaturedecreases,thestrength,hardness,andthemodulusofelasticityincreaseforalmostallthemetals.MetalsandnonmetalsAbilitytodonateelectronsandformapositiveionCrystallinestructureHighthermalandelectricalconductivityAbilitytobedeformedplasticallyMetallicluster(光泽)orreflectivityBody-centeredcubic:columbium,barium,vanadium,(钶，钡，钒)Face-centeredcubic:calcium,aluminum,copper,lead,nickel,goldHexagonalclose-packed:zinc,titanium,magnesiumThereareseveralwaystoprotectagainstcorrosion.CorrosioncanbepreventedorlessenedbyCoatings,Designconsiderations,Environmentalcontrol,Alloying,amongothersCeramiccompounds:Canbedefinedasinorganiccompoundsmadebyheatingclayorothermineralmattertoahightemperatureatwhichtheypartiallymeltandbondtogether.7Traditionalceramicsarederivedandprocessedfromclayornonclayminerals.Mostadvancedceramicsareproducedfromfine,relativelypoorpowersusingnewtechnologyThepropertyofceramicsExtremehardnessHeatresistanceCorrosionresistanceLowelectricalandthermalconductivityLowductility(brittleness)Poresaffectthestrengthofceramicsintwoways：theyproducestressconcentrations.Oncethestressreachesacriticallevel,acrackwillformandpropagate.poresreducethecross-sectionalareasoverwhichaloadcanbeappliedand,consequently,lowerthestressthatthesematerialscansupport.DefinitionofglassGlassisaninorganicproductoffusionwhichhascooledtoarigidconditionwithoutcrystallization.GlassformationGlassformationoccursinmaterialsofallchemicaltypes:covalent,ionic,molecular,metallicandhydrogenbondedmaterials.Glasshavebeenmadefromelement,simplechemicalcompounds,complexorganicmolecules,saltmixturesandalloys.thereisnoparticularlyadvantageouswayofgroupingglassformingmaterials.CompositionofoxideglassMainoxidesinglassGlassformers:anoxidewhichformsaglasseasily（形成体）B2O3,SiO2,P2O5...Glassmodifiers:（修改体）Li2O,Na2O,K2O,MgO,CaO...Intermediates:（中间体）TiO2,ZnO,PbO,Al2O3Twomodelofglass1continuousrandomnetworkmodel2randomclosepackingmodelPhysicalpropertiesDensity:glasscooledatvariousratesfromabovetheannealingpointwilldifferindensitywiththemorerapidlycooledglasseshavingalowerdensityStrength:Themeasuredmechanicalstrengthofglass