A model for predicting the temperature field during selective laser melting

Abstract

To solve the problem that the thermal behavior of powder bed during SLM process is difficult to be analyzed by direct test measurement, a model for predicting the temperature field of AlSi10Mg molten pool in SLM process was established based on the finite element method. In the prediction model, the thermal properties of the material and the variation of laser power absorptivity with temperature were taken into account; the laser heat source was regarded as a 3D Gaussian body heat source, and successfully implemented that the element properties of the material were transformed from powder state to solid state in real time. Through the simulation, the influence of laser power and scanning speed on the thermal behavior of powder bed was investigated, and the validity of the model was verified by experiments. The experimental results were in eminent agreement with the predicted results, and the prediction error was lower than 7%. Based on this model, the process parameters can be optimized according to the obtained law of variation of the thermal behavior of the molten pool, reducing the number of intensive tests and improving the process stability of SLM. Keywords: SLM, Finite element, Temperature field, Molten pool, Process parameters