Instability of surface combustion on exposure to laser radiation

An analysis is made of laser heating of a material on the surface of which an exothermic reaction takes place (oxidation). It is shown that there are critical values of the radiation parameters (beam radius and intensity) above which the thermal field becomes unstable and a combustion wave propagates without restriction over the surface of the material. The characteristic instability evolution times are found. The theory developed in the present paper agrees with the results of experiments on laser combustion of metals.