资源描述：
《al4cumg合金的半固态成形研究》由会员上传分享，免费在线阅读，更多相关内容在学术论文-天天文库。
1、西北工业大学工学硕士学位论文AbstractItisimportanttostudydeformationbehavior,deformationmechanismandmicrostructureevolutionofsemi-solidalloysbecausethesemi-solidalloyhasspecialcharacterization.Toestablishtheconstitutiverelationshipconsistentwithpracticeandcouplewithplasticdeformationandheattr
2、ansferwillbebeneficialtorealizethedistributionofstress,strainandtemperatureraiseduringthedeformationprocessesTopredictwhetherdefectsoccurornotandoptimizetheprocessparameterscouldprovidescientificfoundationofmetalforming.Inthispaper,deformationbehaviorofthesemi-solidAI-4Cu-Mgall
3、oyhasbeeninvestigatedbyisothermalcompression.Efectoftheprocessparameters,includingdeformationtemperature,strainandstrainrate,ondeformationbehaviorhasbeendeeplydiscussed.Basedonthedeformationbehaviorofsemi-solidAl-4Cu-Mgalloy,aconstitutiverelationshipofsemi-solidalloyhasbeenesta
4、blished.Ithasbeenprovedtobeasimplemodel,whichcanrepresentthedeformationbehaviorofsemi-solidalloys.WritingtheconstitutiverelationshiptoFEcode,acoupledsimulationofplasticdeformationwithheattransferhasbeencarriedoutinthebackwardextrusionofsemi-solidAl-4Cu-Mgalloy.Efectoftheprocess
5、parameters,includingdeformationtemperature,punchvelocity,heightreduction,extrusionratioandshearfactoroffrictionontheequivalentstress,theequivalentstrainandthetemperatureraiseduringthesemi-solidbackwardextrusionhasbeenstudiedFinally,backwardextrusionofsemi-solidAl-4Cu-Mgalloyhas
6、beencarriedoutTheexperimentalresultisinagreementwiththecalculatedresultintheinitialstageandfinalstage.Meanwhile,microstructureevolutionmightafectthedeformationbehaviorinthesemi-solidstateandshouldbestudieddeeply.Keywords:AI-4Cu-Mgalloy;semi-solid;constitutiverelationship;FEM;ba
7、ckwardextrusion.西北工业大学上学硕十学位论文第一章绪论1.1概述近净成形技术(NearNetShapeTechnique)是指零件成形后，仪需少量机械加工或不再机械进行加工，就可用作机械构件的成形技术。它是建立在新材料、新能源、机电一体化、精密模具技术、计算机技术、自动化技术和模拟技术等多学科高新技术成果基础上，改造了传统的毛坯成形技术，使之由粗糙成形变为优质、高效、精密、轻量化、低成本的成形技术。它使得成形的机械构件具有精确的外形、高的尺寸精度、形位精度和好的表面粗糙度。近净成形技术属于先进制造技术的一种。近年来，随着我国制造业，尤
8、其是机械制造业的迅猛发展，要求生产过程节约材料、节约能源、提高资源利用率己经成为能否以低成本、高质量、高效率
