Effects of heat source type and FE time discretization strategy on predicting temperature histories during laser direct energy deposition process of Fe-based alloys.

In this study, the temperature evolutions in the laser direct energy deposition process of Fe-based metallic materials are numerically investigated using the finite element method. The effects of heat input method and the model reduction strategy based on the lumped approach in the simulations were studied numerically. The simulations were carried out following the depositions of single beads, single layers, and multiple layers. The results of the simulations were compared with the temperature evolutions obtained in the experiments as well as the melt pool shapes observed in the experiments. Based on the numerical and experimental results, a numerical modeling strategy is proposed for estimating the temperature distributions in the laser direct energy deposition processes in a time-efficient manner, while maintaining the accuracy of the simulation. The proposed simulation strategy used rough simulation time steps for estimating the overall temperature rise, in addition to using only a few fine simulation time steps for predicting detailed temperature distributions at certain simulation times of interest. The proposed strategy allowed the FE model to reduce calculation time by more than 3.8 times while also accurately simulating the detailed temperature of the region of interest. [ABSTRACT FROM AUTHOR]