INFLUENCE OF SURFACTANTS ON HEAT AND MASS -TRANSFER IN MELTING OF THESURFACE OF A SUBSTANCE BY A LASER-PULSE

It is shown theoretically and numerically that the convective flow reg imes during melting of the surface of a substance by a laser depend on the relationship between dimensionless thermocapillary and concentrat ion-capillary numbers, that an inhomogeneity of the distribution of su rfactant particles and unsteady surface heating may give rise to a mul tivortex structure of surface flows, and that the development of multi vortex flows facilitates deeper penetration of an alloying substance i nto a laser melt.