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A model that accounts for the temperature variation in a powder particle based on heat transfer by convection and radiation at the surfac is discussed with consideration of phase change of the particles, extending to evaporation, melting, and resolidification Evaporation in plasma spraying processes is also discussed. Internal phase-change interfaces may exist as well as those at the surface. Nonisothermal effect of heating was seen in numerical results especially for such materials as zirconia, which is studied in particle form, as is nickel.

A collision-limited kinetics model shows nonequilibrium pulse laser surface melting and resolidification of the pure metals Al, Cu, Ti and Ni, and dilute Al-Cu binary alloys. The rate of resolidification depends on the laser flux, pulse duration and substrate material properties. The variations in the pattern of interface velocity indicates strong interactions between heat transfer, solute partitioning, phase change kinetics and initial solute concentration.

Experiments are performed to study the interfacial thermal conductance between molten copper and a cold metallic substrate during the solidification stage. Several metallic substrates are employed in the study, namely, copper, aluminum and stainless steel. Results suggest that the interfacial contact during the cooling of molten copper is a very dynamic process with three main process phases.