Influence of ω phase precipitation on mechanical performance and corrosion resistance of Ti–Nb–Zr alloy.

A recently investigated Ti–24 at.% Nb–2 at.% Zr alloy was cold-rolled with reductions of 75% and 95%, and the resulting materials were heat-treated under the same conditions. The two types of specimens obtained through this procedure show the same phase composition. Precipitation of an isothermal ω phase leads to some improvement in the properties of the 75%-rolled specimens. The 95%-rolled and subsequently heated specimens exhibit different performances compared to the 75%-rolled samples heated under the same processing conditions. The stress-induced martensitic transformation is inhibited in the 95%-rolled specimens, owing to the combined effects of the isothermal ω phase and texture. The Ti–24 at.% Nb–2 at.% Zr alloy shows open circuit potential and corrosion behavior similar to commercially pure Ti. The corrosion resistance of the alloy is reduced upon precipitation of the ω phase, owing to an unstable passive film. [ABSTRACT FROM AUTHOR]