原位内生NiAl基复合材料的研究

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1、上海交通大学博士后士学位论文原位内生NiAl基复合材料的研究姓名：姜东涛申请学位级别：博士后士专业：材料学指导教师：@2000.9.1略f吐6，．z稿黪锯l论吻Ⅳ，’∥f娶喝／酏压、为学易乡奴多么氧f<丫5}；＆芬扩弓々挈。幸袅辱’f{)么哕2敌拿烈以’舄‘f芝像彳之彬蓼肜夕7彦始科李牛。z彳宦钗山可{弘5c·A石枷钞卜；级；钳夕咄凌私刷f场艺辱匆彻够f亍，五存咳．海物f司：，v汹}复食射≠’2酱媛夸硝坟寥一⋯。，r——⋯⋯一一+拶乞塑型锣ABSTRACTIntermetallicNiAlhasthedesirablepropertycombinationoflOWdensity,hi

2、曲meltingpointandexcellentoxidationresistance，however,itsusehasbeenlimitedbecauseofitspoorductilityandfracturetoughnessatroomtemperatureandinadequateelevatedtemperaturestrength．Combustionsynthesistechniquewasusedtofabricate伽一situNiAlmatrixcomposites．Thesyntheticfeasibility,reactionmechanism．micro

3、structure，andmechanicalpropertieswerestudied．NiAImatrixcompositereinforeedwithHeuslerphaseandTiCparticleshasbeensuccessfullymadebycombustionsynthesistechnique．Thereexistadenseneedle—likeHeuslerprecipitatesintheNiAlgrains．Interestingly,theseprecipitatesdistributeveryregularly．Thestrengthofthecomp

4、ositesisgreatlyhi曲erthanthemonolithicNiAl．111ecompositesshowveryhighstrengthevenatelevatedtemperaturesbutlittleductilityatlOWtemperatures．ThestrengthofNi一40Al—lOTiiS5timesthatof’monolithicNiAlat10000C．AmultiphasecompositeNiAl一TiC—A1203iSreactionsynthesizedfromNi、Al、Ti02andCpowdermixtures．Theresu

5、ltsofthermodynamicanalysisareinagreementwiththeexperimentalfacts．TherearesomesmallTiCparticlesexistedintheA1203particle．Suchphenomenonareconcernedwimthecharacteristicsofthein—situreaction．ThestrengthofthecompositeissuperiortothebinaryNiAl．howeveritdecreasesrapidlyathi曲temperatures．Anin-situcompo

6、sitefNi一20AI一30Fe)一TiChasbeenmanufacturedbyusingt11ecombustionsynthesistechnique．DuringreactionsynthesisofNi．20AI一30Fe．theFepowderspreventthepowdermixturesfromcompletelytransferringintoproduct，andalittleamountofFeparticleareleftintheproduct．TheadditionofTiandCincreasetheheatreleaseandthereaction

7、becomesnearlycomplete．ThemicrostructureofNi一20A1—30FeisamixtureofpandY一’，wheretheY’precipRatesareintheYgrains．ThereexistsalittleamountofA1203particles，whichisoriginatedmainlyfromtheadsorbedOoroxideonthesurfaceoftheoriginalFe