Beta phase stability of Ti-35Nb-6Ta-7Zr-0.7O beta titanium alloy

摘要

Phase stability of metastable beta Ti alloy Ti-35Nb-6Ta-7Zr-0.7O (wt.%) in a beta solution treated condition was studied during annealing at 400°C - 700°C for 1 h - 16 h. Resulting microstructure was characterized by scanning electron microscopy; the samples were also characterized by microhardness measurements. The microhardness did not change in any of the annealed condition. The reason follows from the microstructural observations, the a phase precipitation did occur only at the grain boundaries and only at higher temperatures / longer annealing times. Thus, the β phase stability is high and this fact can be used for designing annealing treatments or the thermo-mechanical processing route.