This paperdescribesaninvestigationondifferencesininteractionsbetweenlaserandarcplasmaduring
laser-gastungstenarc(LT)weldingandlaser-gasmetalarc(LM)welding.ThecharacteristicsofLTheat
source andLMheatsource,suchasplasmabehavior,heatpenetrationabilityandspectralinformation
werecomparablystudied.Basedontheplasmadischargetheory,theinteractionsduringplasmadis-
charge weremodeledandanalyzed.ResultsshowthatinbothLTandLMwelding,couplingdischarge
between thelaserkeyholeplasmaandarchappens,whichstronglyenhancethearc.But,theenhancing
effect inLTweldingismuchmoresensitivethanthatinLMweldingwhenparametersareadjusted.