Finite element modelling of transient three-dimensional temperature field of workpiece with a sharp board in laser heat treatment

The experiment of laser heat treatment of workpieces with a sharp board milled to be 90 degrees, 55 degrees, 45 degrees and 35 degrees has been finished to investigate the influences of the sharp board on the temperature field and the heat-affected zone. The spot of laser had been sampled using the thermal paper in two planes of different height h(1) and h(2), and the power distribution of laser has been simulated numerically. A finite element model of numerical calculation is developed to simulate the transient three-dimensional temperature field, and the shade plot and isotherm can be output in any longitudinal and transverse sections and then the hardened zones are determined. The several cross sections of treated workpieces are chosen to make the metallographical analysis and the comparisons with the numerical results. It has proved that the numerical results are in a good agreement with the experimental data and the sharp boards have a great influence on the temperature and the heat-affected zone when laser approaches to the sharp board of workpiece.