Laser melting of nitrides of aluminium, silicon, and boron

An analysis is made of the heating and melting of the surfaces of ceramic samples of aluminium nitride, silicon nitride, and boron nitride by low-intensity laser radiation. It is shown that the thickness of a molten surface layer is governed by the thermophysical properties of the material and by the relationship between its melting point and the intense-evaporation temperature. The derived dependence of the thickness of the molten layer on the radiation intensity is compared with the results of experiments on melting of aluminium nitride. The published experimental results on the laser heating of silicon nitride and boron nitride are interpreted.