Tailoring grain morphology in Ti-6Al-3Mo through heterogeneous nucleation in directed energy deposition

•Almost fully-fine equiaxed grains are obtained in DED Ti-6Al-3Mo by satelliting.•The <100> fiber texture of DED titanium alloy along deposition direction is reduced.•The heterogeneous nucleation mechanism in DED Ti-6Al-3Mo by satelliting is revealed.•The selection of α-variants is gradually reduced with the refinement of β-grains.•Ti-6Al-3Mo with equiaxed grains shows a good combination of strength and elongation.