简介:ThelaserbeamweldingofBT20titaniumalloywasconductedtoinvestigatetheweldshape,microstructuresandproperties.ThefullpenetrationweldcharacteristicsproducedbyCO2laserandbyYAGlaserwerecompared.TheresultsshowthatthefullpenetrationweldofYAGlaserweldingclosesto"X"shape,andweldofCO2laserweldingis"nail-head"shape.Thoseresultfromspecialheatingmodeoflaserdeeppenetrationwelding.ThetensionstrengthofCO2laserandYAGlaserjointsequaltothatofthebasemetal,buttheformerhasbetterductility.Allweldsconsistmainlyoftheacicularαphaseandafewβphaseinmicrostructure.ThedendriticcrystalofCO2laserweldisalittlefinerthanYAGlaserweld.AccordingtheresearchCO2laserisbetterthanYAGlaserforweldingofBT20titaniumalloy.
简介:Theobjectiveofthisstudyistoinvestigatetheinfluenceofaddingtinyamountofmixedrareearth(La,Ce)andSrtoAl-20Cu-5Si-2Nifillermetal,byanalyzingthemicrostructure,wettabilityandmechanicalpropertiesofbrazedjoints.Theresultsshowthawiththeadditionofmixedrareearth(La,Ce)intoAl-20Cu-5Si-2Nialloy,theα-AlsolidsolutionaswellasCuAl_2(Ni)intermetalliccompoundphasesignificantlyreduced,whilemoreAl-SieutecticphaseandAl-Si-Cuternaryeutecticphasewereproduced.Andasmixedrareearth(La,Ce)addedin,thewettabilityofAl-20Cu-5Si-2Nifillermetaldecreased,whiletheshearstrengthofthebrazedjointsincreased.TheadditionofMinorSrmodificatedAl-20Cu-5Si-2Nifillermetal,furtherreducedtheCuAl_2(Ni)intermetalliccompoundphase,whichwaspartiallyreplacedAl-Si-Cuternaryeutecticphase.Asaresult,thetensilestrengthaswellasthewettabilityofthefillermetalwasimproved.