純銅等徑角擠壓過程計(jì)算機(jī)模擬研究.pdf

1、蘭州理工大學(xué)碩士學(xué)位論文純銅等徑角擠壓過程計(jì)算機(jī)模擬研究姓名：唐向前申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：材料加工工程指導(dǎo)教師：丁雨田20090427純銅等徑角擠壓過程計(jì)算機(jī)模擬研究AbstractAsaneffectivematerialpreparationmethodforobtainingbulksubmicronandnanometermateriaIs，ECAPisattractingagreatdealofattentionandcon

2、sideredtobethemostpromisingfbrthepreparationofultrafine—structuredmaterialsECAPisacomplexplasticformingprocessundercoupledef詫ctsofmultifactorswithinteractionbetweenmacrodeformationandmicro—structureevolutionResearchonmac

3、rodeformationandmicrostructureevolutionrulehasbecomeanimponantsubjecturgenttoberesolVedintheleadingneldoftheECAPprocessTherefore，inthisdissertation，asystematicinVestigationonmacromicro—deformationofECAPprocesshasbeencarr

4、iedoutusingnumericalsimulation，AbriefintroductiontotheprojectanditsmainachieVementsareasfollows：AmodelofECAPprocesshasbeendeVelopedbasedonFEM，andsomekeytechnologieshavebeens01ved，suchasmaterialsmodeling，elementselecting，

5、meshing，contactboundary，fiction，choiceofsolverandincrementstep，etcBasedontheplatformofsoftwareDEFORM一3D，themicrostructuremodelsofcopperhaVesuccessf’ullybeenintegratedintothemacro—FEMmodel，andconsequentlysimulationsofECAP

6、deformationandmicrostructureevolutionrealizedThroughcomprehensivesimulationsandanalysesofcoupleddef6rmationandmicrostructureevolutionofECAPprocess，thelawsofdistributionhaVebeendisclosedfordeformedprocess，equiValentstrain

7、nled，deformationuniformity，strainratenled，equivalentstressnledandtemperaturenledTheinnuencesofmainprocessparametersonequiValentstrainfiledhaVebeendisclosed，includingpressroutes，presspassesanddiecornerIntheprocessofECAPde

8、formation，TheequiValenteffectiVestressinsidethematerialisuneVen，themajoreffectstressisconcentratedoncornerofpassagewhenplastometricsetcomeaboutStrainrateismaximumwhenintheregionofdieshearingdeformationInformingprocessofp

9、urecopperECAP，compressionaldeformationmaketemperatureofthemodelincreaseto300℃Thechangeoftemperaturefieldcouldseparate3stagesThelawsofdistributionhaVebeendisclosedfordynamicrecrystallizedVolumefraction，dynamicrecrystalliz

10、edgrainsize，recrystanizedVolumefractionandaVeragegrainsizeTheeff色ctsofpressroutesandpresspassesonmicrostructureeVolutionhaVebeenstudiedandobtainedThereisnodynamicstaterecrystallizeintheearlyperiodofextrusionprocessTheVol