Phase stability change with Zr content in β-type Ti–Nb alloys

The alloying effect of Zr on β-phase stability was investigated in β (body-centered cubic)-type Ti–Zr–Nb alloys. According to both calculations and experiments, the addition of Zr was found to greatly modify the β-phase stability, because Zr worked as a β-stabilizing element in these β-type alloys. The β/βω(+α″) phase-boundary was determined experimentally in the alloys at several Zr content levels. It was shown that the β stabilizing effect of Zr increased with increasing content of the other β-stabilizer element (i.e. Nb) in the alloy.