Influence of laser-induced capillary waves on heat and mass transfer in the arc-augmented laser processing of materials

An experimental study is reported of the influence of capillary waves on heat and mass transfer in molten metal during arc-augmented laser processing by cw CO$_2$ laser radiation of $q\simeq2-4.5$ MW/cm$^2$ intensity. Capillary waves excited on the melt surface by a periodic pulsed reaction of a metal vapour jet had complex dynamics. An analysis of the experimental results indicated a considerable change in heat and mass transfer in the melt when three-dimensional vibrations were excited, compared with the processes that occur at intensities of $q<2$ MW/cm$^2$. Such changes enhanced the mixing of the alloying elements (compared with the familiar alloying methods) and established the optimal (for surface processing of metals) shape of a molten bath.