Prediction Model and Experimental Verification of Density in Laser Selective Melting

A prediction model of the relative density based on the process parameters was established, which can effectively predict the pores caused by lack of fusion, and provide more reference for the selection and optimization of laser selective melting process parameters. The finite element analysis and numerical calculation software were used to obtain sizes of the melting pool and to simulate the splicing morphology of the melting pool with multiple layers and traces, and thus to predict the relative density under different process parameters. At the same time, the fluctuation coefficient, the deflection angle and the angle of scan vectors rotation between layers were introduced into the prediction model of melting pool to account for the influence of the size fluctuation of the melting pool, the inclination of the melting pool, and the angle of scan vectors rotation between layers on the simulation results of the molten pool. Finally, the feasibility of the prediction model was confirmed by the selective laser melting experiments of HR-2 stainless steel. The results show that the predicted results of the model are in good agreement with the experimental ones of the melting pool of the samples, and the relative density deviation between prediction and the experiment is within 2%.