Numerical Simulation and Experimental Research on the Temperature Field of Selective Laser Melting of IN738LC Alloy

Optimization of the selective laser melting process parameters based on the thermal behaviour variation of the melt pool through numerical simulation is an effective means of improving the quality of the formed parts. So, a fully parametric finite element analysis model of the temperature field of the selective laser melting process for IN738LC alloy was developed in the APDL language of ANSYS software, and the heat source model was calibrated by single melt channel forming experiments. The results show that, with the increase in laser power or the decrease in scanning speed, the linear energy density absorbed by the powder increases, the maximum temperature of the melt pool centre increases, the molten metal volume increases, and the melt channel morphology evolves from irregular intermittent to regular continuous long strip; with the increase in scanning speed or the decrease in laser power, the linear energy density absorbed by the powder decreases, the flow capacity of melt decreases, and the melt pool width and depth decrease. The FEM simulations are in good agreement with the experimental results. When the laser power is 270 W and the scanning speed is 1150 mm/s, the single melt channel has a continuous and good shape with few defects.