Fracture in metal–ceramic composites.pdf

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1、COMPOSITESSCIENCEANDTECHNOLOGYCompositesScienceandTechnology64(2004)1167–1178www.elsevier.com/locate/compscitechFractureinmetal–ceramiccompositesParulAgrawal*,1,C.T.SunSchoolofAeronauticsandAstronautics,PurdueUniversity,WestLafayette,IN47907-1282,USAReceived20

2、August2003;receivedinrevisedform21August2003;accepted22September2003Availableonline15December2003AbstractThisresearchfocusesonfracturemechanismsinmetal–ceramiccomposites.Twoco-continuouscomposites,Cu/Al2O3andAl/Al2O3andametal–matrixcompositeAl/SiCwerestudied.I

3、twasfoundthateachcompositedisplayedadifferentfracturemech-anism.Thecrackpropagationinsidethemetal–matrixcompositewasdominatedbytheAlmatrixcharacteristics.However,crackpropagationinsideboththeco-continuouscompositeswasinfluencedbytheirmicrostructure,thermalresidu

4、alstressesandcon-tiguity.Thisuniquefracturecharacteristicofco-continuouscompositeshasbeenelucidatedinthepresentresearchbyexperi-mentationaswellascomputationalmodeling.Insituthree-pointbendtestswereperformedinsideanenvironmentalscanningelectronmicroscopechamber

5、toobservecrackgrowthatthemicrostructuralscale.Finiteelementmodelingwasperformedbyusingglobal–localapproachtosimulatecrackpropagationandunderstandtheeffectsofthemicrostructureandthermalresidualstresses.Itwasshownthatthecrackpropagatedinsidethemetallicphaseandatt

6、heinterfacefortheCu/Al2O3compositeduetoahighleveloftensilethermalstressesinsidethemetallicphase,aswellasduetolowcontiguityofceramicphase.However,inthecaseofAl/Al2O3composite,thecrackpropagatedinsidetheceramicduetosignificantlysmallerthermalstressesinsidethemeta

7、llicphaseaswellashighercontiguityofceramicphase.Ó2003ElsevierLtd.Allrightsreserved.Keywords:B.Fracture;B.Interface;C.Crack;D.Scanningelectronmicroscopy;Co-continuouscomposites1.Introductionmechanismsinsidethetwocategoriesofmetal–ceramiccomposites.Metal–ceramic

8、compositeshavebeenatopicofSufficientliteraturecanbefoundforthefractureofinterestformanyresearchersforvariousreasons[1–5].metal–matrixcompositeswithreinforcedceramicparti-Themotivatio