Kinetics of a phase transition during laser evaporation of a metal

A study is made of a change in the degree of nonequilibrium of an evaporation process occurring under different regimes of interaction between laser radiation and the surface of an absorbing medium. A numerical solution of the heat conduction equation for a condensed medium is used together with the equations of gasdynamics for a vapor subject to an allowance for additional relationships on the irradiated surface governing the kinetics of a nonequilibrium phase transition. The results obtained indicate the existence of a nontrivial region of transient evaporation characterized by a constant Mach number M = 1 between limits that depend strongly on the laser interaction regime.