Simulation of dynamic temperature field during selective laser sintering of ceramic powder

It is difficult to obtain the dynamic temperature field and the variation pattern with the experimental method as the temperature field changes very fast in the laser sintering process. In this study, a mathematical model for the dynamic temperature field was established during selective laser sintering (SLS) with nano-hydroxyapatite (HAP) ceramic powder. The dynamic loading of a moving laser heat source with a Gaussian distribution was realized with ANSYS Parameter Design Language. The variation pattern of a three-dimensional transient temperature field at different speeds of the moving laser heat source was analysed as the change of thermal physical parameters with temperature was taken into account in the developed model. The results show that the maximum temperature point on the sintered layer surface is slightly lagged from the laser spot centre with the moving laser heat source when the offset distance is 0.4 mm, laser power is 10 W, laser spot diameter is 2 mm and laser speed is 200 mm/min. The temperature decreases rapidly with the increase of sintering depth. The temperature field that the characteristic microstructure of the sintered parts represents coincides with that by the analysis with finite element calculation. This study may provide useful guidance for selecting the reasonable processing parameters during SLS.