選択的レーザ溶融付加製造における複数トラック・複数層走査時のエピタキシャル成長組織予測のためのmulti-phase-fieldフレームワーク

抄録

In this study, a multi-phase-field (MPF) framework for predicting epitaxial grain growth in selective laser melting (SLM) additive manufacturing (AM) with multi-track and multi-layer scanning was developed. The spatiotemporal change in temperature was approximated using the Rosenthal equation, which provides a theoretical solution for the temperature distribution due to a moving point heat source. The powder bed was modeled as a polycrystalline layer. Large-scale MPF simulations for SLM-AM were performed using parallel computing with multiple graphics processing units. Using the MPF framework developed herein, we simulated SLM-AM with four tracks and four layers for 316L stainless steel. By observing the epitaxial grain growth process on two-dimensional cross-sections and in three dimensions, we clarified a typical growth procedure of grains with characteristic 3D shapes. The MPF framework will potentially enable a systematic estimation of the material microstructures formed during SLM-AM.

 

Mater. Trans. 64 (2023) 1150-1159に掲載．式（1）を修正．

Fig. 4　Grain structures on the outer surfaces of the computational domain at the completion of all tracks. Color indicates the number of grains and the grain boundary is indicated by the grey line.