Transient mass transport mechanism during continuous laser irradiation of metals and the synergetics of arc-augmented laser melting

A new mechanism of mass transport in a melt, active in the course of a transition from thermocapillary convection to melting of a metal, is considered. The existence of convective flows of the melt, whose pattern differs from that of thermocapillary convection, is pointed out. It is shown that the effect in question occurs more generally and it probably applies during continuous irradiation of melts and liquids by laser radiation of different wavelengths. The characteristic features of the melting of metals in the course of arc-augmented laser interaction are explained by the new mechanism.