TC21合金的熱變形行為及其組織演變.pdf

1、大連理工大學碩士學位論文TC21合金的熱變形行為及其組織演變姓名：趙建國申請學位級別：碩士專業(yè)：材料物理與化學指導教師：張士宏20080601TC21合金的熱變形行為及其組織演變TheDeformationBehaviorandMicrostructureEvolutionofTC21AlloyduringHotWorkingAbstractAsoneofthekeyaerospacematerials，titaniumalloysar

2、edevelopingtotheDamageToleranttype，withdemandonhighstrength，ductilityfracturetoughnessandlowcrackgrowthrateBasedonTi62222Salloy，theTC21alloyisdesignedasan11OOMPastrengthclassandhighDamage—ToleranttitaniumalloyThedeformat

3、ionbehaviorandmicrostructureevolutionofTC21alloywereilwestigatedat僅8zone，near8zone，quasipzoneandzone；theProcessingMapswereestablishedbasedonDynamicMaterialModel，appliedfordirectionoftherealforgingprocessThetruestress—str

4、aincurvesofTC21alloyareobtainedthroughisothermalcompressiontestsonaGleeble3500thermalmechanicalsimulator；theeffecttemperatureandstrainrateontheflowstressiSdiscussed，andthehyperbolicsineArrheniusconstitutiveequationiSappl

5、iedtOmodelthepeakstressasafunctionoftemperatureandstrainrateThedeformationbehavioristhendiscussedbasedoncalculateddeformationactivationenergyThehotupsettingprocessofTC21alloywassimulatedutilizingfiniteelementmethodcouple

6、dinthenumericalsoftwareofDEFORM2Dandinhomogeneousdeformationwithbulgingphenomenonwasanlysised；thecrosssectionalongtheaxialdirectionisdividedtothreezonesbasedonlocalstraincontour；thedeaddeformationzone，thelargedeformation

7、zoneandthefreedeformationzoneBythemetallographicexaminationofthedeaddeformationzone，themicrostructurecharacterizationwasdiscussedjustbeforebeginningofdeformationathightemperaturesAccordingtothemicrostructureexaminationof

8、thelargedeformationzone，theeffectoftemperatureandstrainrateonthemicrostructureevolutuionwasanalyzed，andtheflowsoftenmechanismwasthendisscussedBasedontheDynamicMetarialModel，theProcessingMapsofTC21alloywereestablishedattu

9、restrainofO1，03and06respectively；andtheProcesingMapwasdividedtothreezones“thelowstrainratezoneataflphasefield，thehighstrainrateatzone&邯phasefieldandsingle8phasezoneAccordingtothecalculatedenergydissipationratior／values，t

10、heenergydissipationwaysindifferentprocessingzonewerediscussed；thewaysforinstableflowintheinstablezonewerefinallyanalyzed，andtheprocesswindowwasopimizedKeywords：TC21alloy；hotdeformation；microstructureevolution；ProcessingM