简介：ThelaserbeamweldingofBT20titaniumalloywasconductedtoinvestigatetheweldshape,microstructuresandproperties.ThefullpenetrationweldcharacteristicsproducedbyCO2laserandbyYAGlaserwerecompared.TheresultsshowthatthefullpenetrationweldofYAGlaserweldingclosesto"X"shape,andweldofCO2laserweldingis"nail-head"shape.Thoseresultfromspecialheatingmodeoflaserdeeppenetrationwelding.ThetensionstrengthofCO2laserandYAGlaserjointsequaltothatofthebasemetal,buttheformerhasbetterductility.Allweldsconsistmainlyoftheacicularαphaseandafewβphaseinmicrostructure.ThedendriticcrystalofCO2laserweldisalittlefinerthanYAGlaserweld.AccordingtheresearchCO2laserisbetterthanYAGlaserforweldingofBT20titaniumalloy.