Development ofβ-phase Titanium Alloys with Low Young's Modulus

研究了医用Ti-Nb-Ta-Zr合金的弹性性能。发现室温冷却后，多晶的剪切模量′和c44减小，导致室温下多晶的杨氏模量较低。ω相的形成改变了c′和c44的温度依赖性，使室温下的c′和c44升高。因此，ω相的形成增加了室温下多晶的杨氏模量。而在低β相稳定性、低c′和c44的β相基体中形成ω相并不会导致c′和c44的大量增加。因此，少量的ω相形成有助于控制微观结构，从而实现低杨氏模量与高强度的兼容。

Elastic properties of Ti-Nb-Ta-Zr alloys developed for biomedical application were investigated. It was found that shear moduli c' and c44 decrease upon cooling from room temperature, which gives rise to the low Young's modulus of polycrystals at room temperature. The formation of ω-phase changes the temperature dependence of c' and c44 and increases c' and c44 at room temperature. Therefore, the formation of ω phase increases the Young's modulus of polycrystals at room temperature. However, the formation of ω-phase in theβ-phase matrix exhibiting lowβ-phase stability and low c' and c44 does not cause a large increase of c' and c44. Thus, the small amout ofω-phase formation is useful for the control of microstructure which achieve a low Young's modulus compatible with a high strength.