Finite element heat transfer analysis in selective laser melting of AlSi10Mg alloy using bi-directional scan strategy: Enhanced thermal conductivity considerations

Abstract

In the present work, a 3D finite element model was created using the commercial ABAQUS software to analyze the selective laser melting process of AlSi10Mg powder in a bidirectional multi-track, multi-layer configuration. The focus of this investigation was to examine distribution of temperature, melt pool geometry, thermal history, and the temperature change rate. To improve the accuracy of the results, the enhanced thermal conductivity was utilized to incorporate the Marangoni convection effect. The results revealed that, in the initial track, the maximum temperature and dimensions of the melt pool increased, ultimately reaching a plateau as the deposited path extended. However, using a bidirectional scan strategy, the maximum temperature at the second track reached its peak and then stabilized. While the maximum heating and cooling rates in the first track showed a nearly identical trend, both parameters decreased at the beginning of the second track and then began to rise again. It can be attributed to the overlapping of the molten zone between the first and second tracks. With an increase in the number of tracks, the maximum temperature, melt pool width, and depth increased until they reached a steady state, with specific values of 2093 K, 258 μm, and 150 μm, respectively. Introducing more layers initially caused an increase in the maximum temperature and dimensions of the melt pool, which eventually reached a steady-state condition. Finally, temperature distribution of the steady-state simulated melt pool was found to match with thermal behavior and eutectic Si features of the experimental sample.