Effect of precipitation phase on microstructure and superelasticity of cold-rolled beta titanium alloy during heat treatment

TiNbTaZr beta titanium was developed for medical applications. Heat treatment was carried out on cold-rolled specimen. Effect of precipitation phase on microstructure and superelasticity of cold-rolled beta titanium alloy was studied. The deformation defects accelerate the transformation of secondary phase during heat treatment, which makes the transformation from β phase to ω phase come true at 573 K. High strength around 1150 MPa is obtained at 673 K. Stress-induced α′′ martensite transformation is induced in the cold-rolled specimens followed by heat treatment at 773 K along rolling direction, 45° from rolling direction and transverse direction, respectively.