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 omega 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 omega 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 omega phase, owing to an unstable passive film. (C) 2016 Elsevier Ltd. All rights reserved.