Gd对ZK60镁合金组织与力学性能的影响-论文.pdf

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1、Availableonlineatwww．sciencedirect．com一Transactionsof蜷ScienceDirectNonferrousMetalsSocietyofChinaELERPressTrans．NonferrousMet．Soc．China23(2013)2568—2576www．tnmsc．cnEffectsofGdonmicrostructureandmechanicalpropertyofZK60magnesiumalloyZheng—huaHUANG,Wen-junQI，JingXUGuangzhouResearchIn

2、stituteofNon·ferrousMetals，Guangzhou510650，ChinaReceived12July2012；accepted15November2012Abstract：Microstructuresandphasecompositionsofas—castandextrudedZK60—xGd=0—4)alloyswereinvestigated．Meanwhile，thetensilemechanicalpropertywastested．WithincreasingtheGdcontentas—castmicrostructu

3、reisrefinedgradually．Mg-Zn-Gdnewphaseincreasesgradually,whileMgZn2phasedecreasesgraduallytodisappear．Thesecondphasetendstodistributealonggrainboundarybycontinuousnetwork．As．casttensilemechanicalpropertyisreducedslightlyatambienttemperaturewhentheGdcontentdoesnotexceed2．98％．Atierext

4、rusionbyextrusionratioof40andextrusiontemperatureof593K，microstructureisrefinedfurtherwithdecreasingtheaveragegrainsizeto2umforZK60-2．98Gdalloy．Brokensecondphasedistributesalongtheextrusiondirectionbyzonalshape．Extrudedtensilemechanicalpropertyisenhancedsignificantly．Tensilestrengt

5、hvaluesat298and473Kincreasegraduallyfrom355and120MPaforZK60alloyto380and164MPaforZK60-2．98Gdalloy,respectively．Extrudedtensilefracturesexhibitatypicalcharacterofductilefracture．Keywords：ZK60magnesiumalloy；Gdmodification；extrusion；microstructure；mechanicalproperty；fracturemorphology

6、distributionandvolumefractionofsecondphasecan1IntrOducti0nalsoaffectthetensilemechaniea1propertyofmagnesiumalloyssignificantly[7]．Therefore，thepresentworkisMagnesiumalloyswithhighspecificstrengtharefocusedonstudyingthemicrostructuresandtensileusedwidelyinautomotive，communicated，ele

7、ctronicmechanicalpropertiesofas．castandextrudedandaerialindustries[1]．WroughtmagnesiumalloysZK60_xGd=0—4alloysindetail，andthendiscussingexhibithigherstrength，beRerductilityandtheroleofgrainsizeandsecondphaseonthecomprehensiveproperty；however,theirplasticityisstillstrengtheningandde

8、formationmechanism．relativ