Simulation of the Temperature Field During the Selective Laser Melting (SLM) of a Ni-based Alloy Powder onto a Steel Plate

摘要

The temperature field of a Ni-based GH4169 alloy powder during selective laser melting (SLM) with a Nd:YAG laser onto a Q235 steel plate substrate was studied. When the scanning speed was constant, the meltpool width and depth increased with the increment of laser power. Because the heat resource density of the laser beams increased with the increasing laser power. When the laser power was constant the highest temperature in the meltpool, the meltpool width and depth increased with the decrease of scanning speed. The reason was that the interaction time between laser beam and powder increased, and the heat flux increased, which resulted in the increase of the meltpool size and the scan line width. The temperature in middle of single track was lower than that of both ends, there were larger temperature gradient and high thermal stress in the position of scanning direction alteration, which gave rise to the occurrence of warping deformation. When the layer thickness was 0.15mm, laser power was 150W, scanning speed was 150mm/min. the GH4169 alloy powder was successfully prepared by the SLM process.