Grain selection and growth orientation of prior-? phase for Ti-6-4 during additive manufacturing: insights from a modeling perspective

The microstructure of Ti-6-4 components produced by additive manufacturing suffers from the coarse and elongated prior-? grain, which leads to a decrease tensile behavior occurrence anisotropy. To understand control grain evolution, multiscale simulation is applied investigate relationship between selection, growth orientation, molten pool morphology with different deposition layer numbers processing parameters. accuracy validated experiments in both qualitative quantitative ways. Results show that when unfavorable orientation loses competitive its neighbors, there will be great chance blocked eliminated following layer-and-layer deposition, increase width. size increases remarkably as number increases, lays heavy burden on stability pool. analytical also deduced. flat causes grains <001> direction close building have greater survival potential. Besides, decreasing line power energy shows little effect especially deposited large. revealing mechanisms help understanding further controlling evolution.