Influence of surfactants on heat and mass transfer in melting of the surface of a substance by a laser pulse.

It is shown theoretically and numerically that the convective flow regimes during melting of the surface of a substance by a laser depend on the relationship between dimensionless thermocapillary and concentration-capillary numbers, that an inhomogeneity of the distribution of surfactant particles and unsteady surface heating may give rise to a multivortex structure of surface flows, and that the development of multivortex flows facilitates deeper penetration of an alloying substance into a laser melt.