Yoon Suk Choi¹, Jaewoong Kim¹, Seulbi Lee¹; ¹Pusan National University

The variation of melt pool geometries was investigated experimentally and numerically as a function of process parameters for single tracks of Alloy 718 processed by the laser powder bed fusion (PBF). The depth and width of melt pools were measured and related to PBF process parameters. The thermal analysis using finite element method (FEM) was performed to predict the width and depth of melt pools under different PBF process parameters. Here, the laser absorptivity and penetration depth of the heat-source model for the thermal FEM were set to vary to capture the depth and width of melt pools with different PBF process parameters. The resulting optimum variations of the laser absorptivity and penetration depth were found to be uniquely formulated as a function of a new energy density-related parameter, which is the liner energy density multiplied by the laser power. The detailed underlying physics was investigated and will be discussed.