Initial stage of the development of three-dimensional periodic structures in laser melting

The initial stage of three-dimensional periodic structures developing during the laser melting of solids is numerically simulated. The temperature nonuniformity caused by reflectivity variations along a capillary wave leads to a self-consistent melt displacement under the action of the temperature gradient due to the temperature dependence of the surface tension coefficient. Based on the numerical solution of the simplified Navier–Stokes equation, the transformation of the initial sinusoidal perturbation of the melt surface is investigated at the stages of self-consistent laser heating and the subsequent cooling. The derived surface shape well agrees with experimental data.