材料科学与工程导论总复习

Aboutthiscourse(contd),4.CourseevaluationHowtoassessthelearningquality?Finalexam70%weight(multiplechoice,analysisandcalculation,English/Chinesealternatively)In-classquiz30%weight(1quiz/Per2weeks,totally6quizzes)HomeworkByyourchoice,notamust,5.Textbook:D.R.AskelandandP.P.Phule,EssentialsofMaterialsScienceandEngineering(材料科学与工程基础),TsinghuaUniversityPress,2005(影印本).,Evolutionofmaterials,Ourtasks,challengesandgoals,StrongerTougherLighterCheaperSaferSmarterFriendly,Ourtasks4componentsinmaterialsresearchSolidificationdefectsTypicalsolidificationofsolid-solutionalloybyPD,SolidificationofmaterialsManynon-ferrousaregood-lookingincolorandshining(goodforornaments装饰物:bracelets,necklaces,ringsetc)Manynon-ferrousalloysaregoodheatconductor;Manynon-ferrousalloysaregoodelectricconductor;Mostnon-ferrousalloysareexpensive(oversteels).,Comparisons:non-ferrousalloys,steels&composites,AluminumalloysAluminumisthethirdmostplentifulelementonearthnexttooxygenandsiliconLowdensity(2.70g/cm3),Magnesium(镁)&beryllium(铍)alloyslightestmetalintheworld,Copperandcopperalloys,Nickel(镍)andcobalt(钴)alloysSuperalloys超耐热合金,Titaniumalloyscorrosionresistance,Refractory&preciousmetals(难熔金属及贵金属),Composites:Teamwork&SynergyinMaterialsAnengineeringmaterialwhichconsistsofmorethanonematerialtype,Structures:matrix基体+interface界面+reinforcement增强体(s).Matrixmaterials:polymers,metal,ceramics.Reinforcements:fibers&particulatesglass,carbon,organic,boron硼,ceramic,metallic,Propertiesofcompositematerials:Excellentmechanicalproperties:Highspecificstrengthandstiffness(ratioofstrength/weight&stiffness/weight)etc.Adjustableproperties:Propertiesofacompositecanbeeasilyvariedbychangingmatrix/reinforcementandtheirfractions.Isotropy:Compositesshowthisfeaturewhenreinforcingparticlesareuniformlydistributed.Anisotropy:Compositesshowthisfeaturewhenfibers/whiskersaredirectionallydistributed.,(a)Tapescontainingalignedfiberscanbejoinedtoproduceamulti-layereddifferentorientationstoproduceaquasi-iso