简介:Automaticgastungstenarc(GTA)weldinghasbeenutilizedtoconnectAZ31magnesiumalloybuttedplateswithAZ61andAZ61-1.0Sbfillerwire.ContrastedtoAZ61fillerwire,theAZ61-1.0Sbfillerwireholdsacomponentof1wt%antimony(Sb).Inthepresentwork,properweldingtechnologyparaneterswereexplored.AndthemicrostructureandperformanceofweldedjointswereanalyzedtoresearchtheinfluenceofSbonmagnesiumalloyweldedjoint.Observedfromthemicrostructureofweldedjoint,additionofSbhasrefinedcrystalgrainsandchangedthepatternofeutecticinbeadandheataffectedzone(HAZ)adjacenttobeadfromdiscontinuousreticulartograininessstructure,whichstrengthentheweaknessofjoint.Inaddition,becauseoftheanchoringactionofMg3Sb2phasesaswellashamperingactiontocrystalboundaryslip,theperformanceofjointweldedbyAZ61-1.0Sbfillerwirehasbeenimproved.
简介:ThefatiguepropertyofAZ31magnesiumalloyanditsTIGweldedjointswereinvestigated.Theultrasonicpeeningtreatment(UPT)wasusedtoimprovethefatiguepropertyoftheTIGweldedjoints,whichwastreatedattheweldtoebytheUPTprocess.ThetestresultsshowthatthefatiguestrengthofthebasemetalofAZ31magnesiumalloysis57.8MPa,andthoseofthefilletjointandthetransversecrossjointarerespectively20.0MPaand17.2MPaat2×106cycles.ThefatiguestrengthsoftwokindsofweldedjointstreatedbytheUPTarerespectively30.3MPaand24.7MPa,whichhavebeenimprovedby51.5%and43.6%,respectively.Thefatiguelifeofthefilletjointspecimensisprolongedbyabout2.74timesandthefatiguelifeofthetransversecrossjointspecimensisprolongedbyabout1.05timeswhenthestressrangeisat40.0MPa.
简介:SolderingofLD31aluminumalloysusingSn-PbsolderpasteafterelectricbrushplatingNiandCucoatingswasnvestigated.ThetechnologyofelectricbrushplatingNiandCuwasstudiedandplatingsolutionwasdeveloped.Themicrostructureofthecoatings,solderedjointandfracturefacewereanalyzedusingopticmicroscopy,SEMandEDX.Theshearstrengthofsolderedjointcouldreachashighas26.83MPa.Theresultsshowedthatreliablesolderedjointcouldbeobtainedat230℃,theadhesionofcoatingsandLD31aluminumalloysubstratewashighenoughtobearthethermalprocessinthesoldering.
简介:LaserweldingwithfillerwireofAZ31magnesiumalloysisinvestigatedusingaCO2laserexperimentalsystem.Theeffectofthreedifferentfillerwiresonthejointpropertiesisresearched.Theresultsshowthattheweldappearancecanbeeffectivelyimprovedwhenusinglaserweldingwithfillerwire.ThemicrohardnessandtensilestrengthofjointsarealmostthesameasthoseofthebasemetalwhenERAZ31orERAZ61wireisadopted.However,whenthefillerwireofER5356aluminumalloyisused,themechanicalpropertiesofjointsbecomeworse.ForERAZ31andERAZ61fillerwires,themicrostructureofweldzoneshowssmalldendritegrains.Incomparison,forER5356fillerwire,theweldshowsastructureofsnowydendritesandmanyintermetalliccompoundsandeutecticphasesdistributeinthedendrites.Theseintermetallicconstituentswithlowmeltingpointincreasethetendencyofhotcrackandresultinfragilejointproperties.Therefore,ERAZ31andERAZ61wirearemoresuitablefillermaterialthanER5356forCO2laserweldingofAZ31magnesiumalloys.