| 摘要 |
PROBLEM TO BE SOLVED: To provide a rod for spine fixing low in an elastic modulus and showing fatigue strength practically free from problems even when being used, e.g., with a screw made of a Ti-6Al-4V ELI alloy.SOLUTION: The rod made of a titanium alloy for spine fixing is obtained by: using, as a raw material, an ingot made of a titanium alloy or titanium alloy powder, the titanium alloy containing a β stabilization element in an amount of 8 to 20 mass% in a molybdenum equivalent and oxygen in an amount of 0.05 to 0.25 mass%, and the balance titanium and inevitable impurities; obtaining a rod made of a titanium alloy via a hot forging step when the ingot is used, and via a powder metallurgical step when the powder is used; and, thereafter, subjecting the rod to a solid solution treatment or a peening treatment. After the solid solution treatment, the rod has a Young's modulus of 60 to 110 GPa and tensile strength of 700 to 1,200 GPa. Further, a deformation-induced ω phase transformation is produced on the surface part thereof.SELECTED DRAWING: Figure 9 |
