Influence of heat treatment on microstructure and compressive property of laser melting deposited TA15 titanium alloy

The TA15 titanium alloy plates were prepared by laser melting deposition rapid prototyping technology using TA15 titanium alloy powder made by vacuum plasma rotating electrode atomization. The alloy was annealed at α + β two-phase region, the influence of annealing temperature on microstructure, hardness and compression strength was studied and the fracture mechanism of the alloy after heat treatment under different temperatures was analyzed. The results indicate that at two-phase region, a special bi-modal microstructure was found after heat treatment, the volume percentage content of primary α decreased slightly and the "forked" morphology became more and more manifest with annealing temperature increasing. The "bamboo-shaped" primary α was acquired when the annealing temperature was in the upper part of the two-phase region. The mean value of hardness shows stability under different annealing temperature. The compressive property is not sensitive to annealing temperature. The ductile fracture characterizes the fracture mechanism. Therefore, the excellent comprehensive mechanical properties can be obtained by adjusting the heat treatment process over a wider temperature range.