Simulation of Thermophysical Processes of Modifying the Surface Layer of a Metal during Laser Heating

The performance properties of machine parts can be significantly improved by laser processing of their surfaces using modifying the melt with nanoscale particles of refractory compounds (carbides, nitrides, carbonitrides, etc.). Nano-sized particles increase the number of crystallization centers and, thus, refine the macrostructures of the solidified metal, improve quality, and harden the surfaces being processed. Thermophysical processes in a moving metal substrate under the action of laser radiation on its surface are investigated by numerical simulation methods. A mathematical model describing the steady-state thermophysical processes in the surface layer of a metal, in particular, the influence of nanoscale powder on the nucleation and growth of the solid phase, is considered. According to the results of numerical experiments, the distribution of the temperature field, the size of the crystallization zone, the area of the treated surface of the substrate, depending on the speed of its movement and the power of the laser radiation, are estimated.