2018 年 59 巻 5 号 p. 858-860
Oxygen was added to Ti–38Nb (mass%) alloys to improve their mechanical properties. Ti–38Nb–xO (x = 0.13, 0.24, 0.46, mass%) alloys were prepared by arc melting, and subsequently subjected to homogenization, hot rolling, and solution treatment. It was found that adding oxygen suppresses the martensite transformation and exhibits strong solution strengthening effect. Single β phase is obtained in Ti–38Nb–0.24O, whereas Ti–38Nb–0.13O is composed of both α′′ and β phases. Both alloys exhibit double yielding phenomena during tension, indicating a stress-induced martensitic transformation. Ti–38Nb–0.46O exhibits a non-linear deformation, a low Young’s modulus of 62 GPa, high tensile strength up to 780 MPa, and elongation around 23%, which are promising characteristics for biomedical applications.
