СOMPUTER SIMULATION OF THERMAL FIELDS AND THERMAL CYCLE DURING PULSED LASER TREATMENT OF METALS AND ALLOY

Abstract

The determination and prediction of temperature changes in the heat-affected zone during laser processing of metals and alloys in real time is a relevant and complicated task attracting being in the focus of researchers all over the world. The article presents a two-dimensional computer model of thermal fields and thermal cycle during laser heating of the surface of metals and alloys in the COMSOL Multiphysics® software environment. The simulation was carried out by the finite element method. A 4×4×1.5 mm steel plate was considered as a virtual sample. For the improved prediction of the temperature field and thermal cycle of the calculation model, various boundary conditions and thermophysical properties of the material (density, thermal conductivity and heat capacity, depending on temperature in the range of 20–1500 ℃ (up to the steel melting temperature) were used. These conditions simulate laser nitriding in the medium atmospheric pressure nitrogen. As a result, a computer model that allows one to obtain and analyze thermal cycles and thermal fields when the surface is heated by a pulsed laser beam has been developed. Our model allows one to determine the optimal processing parameters (pulse power, pulse repetition rate, etc.) from the point of view of thermal impact.