Simulation of stress field and deformation control study of 95W-5Ta laser powder bed fusion

In this paper, 95W-5Ta mixed powder is used as the research object. In order to solve the problems of high thermal stress and serious deformation during the forming process of 95W-5Ta laser powder bed fusion (LPBF), numerical simulations are adopted based on the finite element method to simulate the evolution of the stress field in the forming process, and the process experiments are carried out to verify the correctness of the simulation results. The simulation results show that the stress change is a multi-cycle process, increasing the laser power and decreasing the scanning speed will lead to an increase of thermal stress, and the zonal scanning strategy can make the thermal stress uniformly distributed and avoid the stress concentration in the sensitive areas of the part. To analyze the factors affecting deformation, experiments were designed, it was found that the degree of deformation is more sensitive to the laser power, and related to the scan line length, inter-layer intersection angle and scanning strategy. Experiments results showed that a shorter scan line, 67° inter-layer staggering angle and smaller zonal scanning can obtain smaller deformation.