The effect of heterogeneity of a solid surface on its wettability by metal melts has been studied. Contact angles and the character of the melt spreading were discussed as depending on the shape, size, and ratio of heterogeneous patch areas. A mechanism of liquid spreading has been suggested in regard to the local contact angles effect on the three-phase contact line. The system energy computation is exemplified by a cylindrical one-dimensionally spreading drop.

Thermocapillary convection in tin, gallium, and lead melts has been studied. Velocities of surface flows were determined and the criteria of heat and mass transfer - Marangoni, Grashof, and Bond numbers mere estimated. It has been found that the intensity of thermocapillary convection depends on Marangoni's number. Theoretical and experimental results were compared and the causes of their discrepancy were analyzed. it is demonstrated that the capillary-convective mechanism of heat transfer has the decisive role.