高強鋁合金微合金化與電磁成型技術的研究.pdf

1、大連理工大學碩士學位論文高強鋁合金微合金化與電磁成型技術的研究姓名：桂治元申請學位級別：碩士專業(yè)：材料加工工程指導教師：張興國20071201高強鋁合金微合金化與電磁成形技術的研究TechnicalStudyonElectromagneticCastingandmicroalloyofHighStrengthAluminumAlloysAbstraetElectromagneticcasting(EMC)isanewmaterialpr

2、ocessingmethod，acomprehensivesubjectbasedonmagneto—hydrodynamics(MHD)andcombinedwithmetallurgicalengineeringTheoutstandingmeritsofEMClieinitshighsmoothsurfac冶，goodmechanicalpropertiesandhighprodnetionefficiency，whichhasb

3、ecomeanimportantmethodtealizetandemrollingincontinuouscastingandproducehighqualifiedaluminumalloysHowever，thevarioustechnologicalparametersandhighcontrolprecisionrequrirerealizingauto—controlofEMCinindustryElectromagneti

4、ccontinouscasting(EMCC)couldclearuplotsofdefectssuchassegregation，lardiningotsurfaceconsequentlytheingot、】l，imbettersurfacequsaityandmiaerostmetureTheeffectsofZronthecastmierostructureandmechanicalpropertiesofAI40Cu14Mg0

5、5MnhighstrengthaluminumalloybyelectromagneticcontinuouscastingwerestudiedbyusingopticalmicroscopehardnessmeasurementtensiletestscanningelectronmicroscopeandXRDetTheresultsshowthatZrCanremarkablyimprovethepropertiesofallo

6、ys，Thestrengtheningmechanismaleconsideredasfinegramstrengtheninganddispersionstrengthening；ThemacrohardnessofthealloywithZrincreaseby391％，thetensilestrengthandtheyieldstrengthofalloywithZrcallraiseabout390％and482％respect

7、ivelyandextendratioimproveby4866％comparedwitllthealloywithoutZrinascaststateThealloywithZrexpressductilefracturemechanism。InthispapertheA14O％SialuminumalloysweremadebyEMCComparedwiththatofdirectchillcasting(DeC)，Resultss

8、howthattheEMCingotshavebetteranduniformgrainmicrostructureandexcellentsurfaceThetensilestrengthofEMCingotsis131％timesaShighasDCCOnesandtheextendratioattainabout25timesinascaststateThefatigueintensionofEMCingotsimproveby2