Thermal coupling inside the keyhole during welding process

Abstract

We present a global analysis of the welding process (plasma, keyhole, thermal coupling...). Experimental energy balances of the process are presented and interpreted for different welding conditions. Then a modelization of the keyhole and of the power deposition inside it allows us to quantify the absorption process inside the keyhole (plasma absorption by Inverse Bremsstrahlung effect and Fresnel absorption). The explanations of our experimental results can then be confirmed. The influence of the welding speed on the keyhole geometry is pointed out, and the consequences on the absorption process are explained.