Fig. 1: Evolution of thermal-fluid-solutal-microstructural multiple physical fields during the melting and solidification of the two-track two-layer LPBF process of ABD-850AM.

Supplementary Movie 1 provides a more intuitive representation of the transport process of the coupled thermal-fluid-solutal multiple physical fields. a–f Simulated thermal-fluid melt pool evolution and the concomitant solute transport during the melting-solidification of the first-track printing of the first layer at 0.099 ms, 0.149 ms and 0.279 ms, respectively. g–i Solute transport process and the solid/liquid interface evolution during the second track printing of the first layer. The snap shots at 1.065 ms, 1.155 ms, and 1.295 ms are used to show the melt pool depth, planar interfaces, and cellular structures. j-o Evolution of the solute field during the two tracks of the second-layer LPBF. It was assumed that the positions of the laser spots were the same as those of the first layer. Max. Vel. means the maximum flow velocity in the melt pool. See Supplementary Figure 1 for the close-up views of the flow field and solute distribution in the melt pools.