Origin of superproperties of Ti-23Nb-1Ta-2Hf-O alloy

Abstract The conditions needed to design gum metal were reconsidered based on the equivalent β stabilizer content required to obtain compositional/microstructural variability in a Ti-24(Nb + Ta + V)-(Zr, Hf)-O system. It was found that 90% cold-worked Ti-23Nb-1Ta-2Hf-O alloy exhibits gum-metal-like superproperties such as ultrahigh strength, ultralow elastic modulus, superelasticity, superplasticity, and Elinvar behavior. These multi-functions can be achieved even with the deformation-induced ω phase if nanodomains and giant faults exist. This suggests that not only the three electronic magic numbers, but also the equivalent β stabilizer content should be considered to attain the superproperties.