Unexpected selection of growing dendrites by very-large-scale phase-field simulation

•Very-large-scale phase-field computation is performed by a graphics processing unit (GPU) supercomputer.•The survival of unfavorably oriented dendrites is observed during directional solidification of binary alloy.•Dendrite–dendrite interactions in three-dimensional space are very complicated.

Dendrites are typical growth morphologies in alloy solidification. However, the ways in which dendrites grow and form solidification microstructures remain poorly understood. Here we show unexpected findings that reveal the survival of unfavorably oriented dendrites and highly complicated dendrite–dendrite interactions in three-dimensional space during the directional solidification of a binary alloy. These results are observed for the first time through very-large-scale phase-field computations performed by a graphics processing unit (GPU) supercomputer and a high-performance algorithm developed for parallel computing.