EBPVD热障涂层的断裂行为研究

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1、天津大学硕士学位论文EB-PVD热障涂层的断裂行为研究姓名：陈哲申请学位级别：硕士专业：材料加工工程指导教师：荆洪阳20090601ABSTRACTAtpresent，inastronautics，aviationandSOmanyindustrydomains，eachkindofthermalsprayingcoatingtechnologyhasalreadybeenwidelyusedinenhancingtheperformanceofthemechanicalcomponentsandlengthenedtheirservicelife．Theintegrity

2、ofcoating／substratesystemiscriticalforthecomponents’security,andtheunionintensityofcoatingshasbecomeoneofmanyimportantstandardsintheapplicabilityofcoatings．Electronbeam-physicalvapordeposited(EB·PVD)thermalbarriercoatings(TBCs)aremostlyusedonthehotsectionofaircraftengineturbinesandhaveplay

3、edanimportantroleinthefieldofaviation．Forthepurposeofanalyzingthecohesionstrengthofcoating／substratesystem,themechanicalpropertyofTBCs，fracturebehaviorcharacteristicsofcoatings，interfacefractureparametershadbeenstudiedinthispaper．ThemicrocosmicappearofEB--PVD—-TBCshadbeenobservedandthecomp

4、onentofeachcoatinghadbeenanalyzedbySEM．Theimportantfunctionofbondcoating(MCrAlY)Wasfound．The3-pointbendtesthadbeenusedtomeasuretheYoung’Smodulus(目oftheTBCs．Eofcoatingswithsamethicknesshavelargedisperse．ThefracturebehaviorofTBCsin3-pointbendspecimenhadbeenobserved．ItWasfoundthatthecracknorm

5、altotheinterfaceinthecoat堍occurredwherea丘xedmomentofforcewasreached．SowhetherthemomentreachedtothecriticalvaluecanbeusedastheconditionofcrackOCCUrrence．TheFEAresultsprovedthepreviousconclusion．nestresslevelsatthedifferentlocationswherethecracksoccurredneartheinterfacealmostweresanle．Ametho

6、dofsimulatingacrackintheinterfacebetweenTBCsandsubstratehasbeenputforward．FEAhadbeenusedtostudyinterfacefractureparametersoftheinterfacebetweenTBCsandsubstrate(thecomplexstressintensityfactorKand先)．TheresultofFEAshowedthetensile10adnearthecracktipweredominant。andthetensileloadhadhighereffe

7、ctthantheshearload．TheresearchfoundtheK-dominantzoneexistednearthecracktjpfortotalspecimensinthistensiletest．KEYWORDS：Thermalbarriercoatings，Young’Smodulus，Interfacefracture，Complexstressintensityfactor,Jc独创性声明本人声明所呈交的学位论文是本人在导师指导下进行的研究工作和取得的研究成果，除了文中特别加以标注和致谢