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1、为了适应公司新战略的发展，保障停车场安保新项目的正常、顺利开展，特制定安保从业人员的业务技能及个人素质的培训计划材料概论,武汉理工大学,pdfMaterial:SolidsusedbymankindtoproduceitemswhichconstitutethesupportforhislivingenvironmentCharacteristicsofmaterials?Havecertaincompositions;?Canbeprocessed;?Withcertainshapeandcolor;?Canbeusedandreusedorrecycled.?特点:?具有一定的成分和配比；
2、?可成型加工；?保持一定形状和外观；?具有使用价值并可回收再利用。材料性能的决定因素?组成材料的各元素的原子结构，?原子间的相互作用、相互结合，?原子或分子在空间的排列分布和运动规律,?原子集合体的形貌特征。Classificationofmaterials?Atomicstructures?Natureofchemicalbonds:?Metallicbond金属键Ionicbond离子键Covalentbond共价键Secondarybond次价键VanderWaalsbond范德华力Hydrogenbond氢键Classification:?metalsandtheiralloys:-m
3、etallicbonding?Organicpolymers:Covalentbonding&secondarybonding?Ceramics:Ionicbonding&covalentbondingMetalsandtheiralloys:?aregoodconductorsofheatandelectricity;?arehard,rigid;?canundergoplasticdeformation?haveahighmeltingtemperature(Tm).Organicpolymers:?madeupoflong-chainmolecules;?areelectricaland
4、thermalinsulators;?arelightandeasilyformable;?thebest-knownorganicpolymersare:?poly(vinylchloride)(聚氯乙烯，PVC);?polyethylene(聚乙烯，PE);?polystyrene(聚苯乙烯，PS)。Compositematerials:Areconstitutedbytwoormoredifferentmaterialswithspecificproperties.?Glassfiberreinforcedresins:lightweightcompositeswithhighmecha
5、nicalstrength?Concrete:anagglomerationofcement,sandandgravelMechanicalproperties:?Thebehaviorofmaterialsdeformedbyasetofforces.?弹性Elasticity?塑性Plasticity?强度Strength?硬度Hardness?韧性Toughness?疲劳特性Fatiguebehavior?耐磨性AbrasionresistancePhysicalproperties:?Thebehaviorofmaterialssubjectedtotheactionoftempera
6、ture,electricormagneticfields,orlight.?电性能Electricproperties?磁性能Magneticproperties?热性能Thermalproperties?光性能OpticalpropertiesChemicalproperties:?Thebehaviorofmaterialinareactiveenvironment.?抗腐蚀能力Corrosionresistance?Atmospherically,?Chemically(salts,acid,alkali)MaterialsEngineering:?Concernedwith?Manu
7、facturing,?Transformation?Shaping?Processing.Thethreemostcommoncrystalstructuresofmetalsare?Body-centeredcubicstructure,?Face-centeredcubicstructure,?Hexagonalclose-packedstructureProductionofsteel:?Pigironcontainstoomuchcarbonandtoomanyimpuritiestobeuseddirectlyinmostapplications.?Itmustbeconverted
8、tosteelinoneofseveraltypesofconverters.Theseconvertersmaydifferinappearance,buttheydothesamething:?burnoffthecarbonintheiron.?Impuritiesareremovedasgasesandintheslag.?Phosphorusandsulfurarereducedtolessthanpercentofthesteel.?Manganesecontentisreducedtoanamountfromtopercent;?Siliconisreducedtoanamoun
9、tfromtopercent.Threeprimaryoresare?magnetite,?hematite,?taconite铸铁概念：castiron,essentiallyanalloyofiron,carbonandsilicon,iscomposedofironandfrom2topercentcarbon,plusmanganese,sulfur,andphosphorus,andshapedbybeingcastinamold.Thetypesandpropertiesofcastiron；whitecastiron(hard,brittle),graycastiron(brit
10、tle,withstandlargecompressiveloadsbutsmalltensileloads),alloycastiron,nodularorductilecastiron(goodcastability,toughness,goodwearresistance,lowmeltingpoint,andhardenability),malleablecastiron(strength,toughness,ductility,andmachinability)StainlessSteel:?Ferritic?Martensitic?Austenitic?PHAlloysadvant
11、agesofusingAl:one-thirdoftheweightofsteel;goodthermalandelectricalconductivity;highstrength-to-weightratio;canbegivenahardsurfacebyanodizingandhardcoating;mostalloysareweldable;willnotrust;highreflectivity;canbediecast;easilymachined;goodformability;nonmagnetic;nontoxicandonethirdofthestiffnessofste
12、el.Magnesium:lightestofallstructuralmetalsgravity:3.Magnesiumweighstimeslessthananequalvolumeofaluminumand4timeslessthanzinc.strength,stiffness,dimensionalstability,strength-to-weightratio.Magnesiumalloyshave?relativelyhighthermalandelectricalconductivities;?goodenergyabsorptioncharacteristics;?Nonm
13、agneticpropertiesThefourtypesofstresses:ductility,tensilestrength,proportionallimit,elasticlimit,modulusofelasticity,resilience,yieldpoint,yieldstrength,ultimatestrength,andbreakingstrengthFourbasictypesofstresses:tensile,compressive,shear,torsion(拉力，压力，剪切力，扭转力)Metalsandnonmetals?Abilitytodonateelec
14、tronsandformapositiveion;?Crystallinestructuregrainstructure;?Highthermalandelectricalconductivity;?Abilitytobedeformedplastically,and?MetalliclusterorreflectivityCrystallineunitstructures?Body-centeredcubic(BCC)?Face-centeredcubic(FCC)?Hexagonalclose-packed(HCP)?Cubic?Body-centeredtetragonal?RhombohedralThereareseveralfactorsthatmayspeedthecorrosionprocess.Amongthesefactorsare?anincreaseintemperature,?thepresenceofcertaingases,?environmentalfactorssuchasacidrain,?metalfatigue,?coldworking/forming,?andothersimilarfactorsCeramiccompounds:Canbe
