Influence of Annealing Treatment on α Phase Globularization, Mechanical Properties, and Corrosion Performance of Hot-Rolled Ti–0.3Mo–0.8Ni Alloy Melted by Electron Beam Cold Hearth Technology

Ti–0.3Mo–0.8Ni (TA10) titanium alloy has attracted attention owing to its mechanical properties and corrosion resistance. Titanium alloy ingots are mostly obtained by vacuum arc remelting (VAR); however, if electron beam cold hearth melting (EBCHM) technology is used, the cost of production can be reduced considerably. However, there have been few studies of TA10 alloy melted by EBCHM technology. The effect of annealing temperature on the microstructure evolution, mechanical properties, and corrosion resistance of TA10 alloy melted by EBCHM technology was investigated in this study. The results demonstrate that the equiaxed α phase grew up and tended to be equiaxed with the increase of annealing temperature. The lamellar α phase transformed into an equiaxed α phase with the average grain size of 5.78 μ m when annealed at 780 °C. The plasticity and corrosion resistance of the alloy increased gradually, while the strength and Vickers hardness decreased with elevated annealing temperature. This is related to the globularization of the α phase and merging of grain boundaries during the annealing treatment. After annealed at 780 °C, the strength and ductility product (UTS × EL) of the alloy was the highest, and it also had a good corrosion resistance. Thus, the alloy annealed at 780 °C has the best comprehensive properties.