低弹性模量骨科植入物材料-β钛合金的研制与实验研究

Bate titanium alloys for orthopedic implants:fabrication,X-ray diffraction analysis,and biomechanics

[目的]研制一种低弹、高强、生物相容性更好的新型β型钛合金骨科植入物材料。[方法]采用国内先进工艺将合金元素(钛、铌、锆)熔炼、浇注成铸造态合金。在高温区锻造,得到锻造变形合金。共制备了四种元素比例不同的合金。采用X线衍射分析、扫描电镜和透射电镜观察合金的微观晶体结构,采用拉伸实验初步研究其低弹、高强的力学性能。[结果]X线衍射分析证实四种合金均为单一的β相。合金抗拉强度:706～874Mpa,弹性模量:59～66Gpa,延伸率:5.4%～20%。时效处理提高了合金的强度,对合金的弹性模量无明显影响。[结论]钛铌锆β合金是一种有前途的骨科植入物材料。

[ Objective] To develop new bate titanium alloys made of titanium, niobium and zirconium （Ti-Nb-Zr） which have higher strength, lower moduli of elasticity and better biocompatibility for orthopedic implants. [ Methods] Alloy elements including titanium, niobium and zirconium were melted together and forged into forging Ti-Nb-Zr. Four kinds of alloys were developed because of the different proportion of alloy elements. All alloys were studied using X-ray diffraction analysis, biomechanical measurements, and scanning and transmission electron microscopy. [ Results] X-ray diffraction analyses showed that all the candidates were beta alloys. The as-cast alloys had the strength values in 584 -718 Mpa, elastic modulus values in 59 -68 Gpa. The peak-aged alloys had the strength values in 706 - 874 Mpa, elastic modulus values in 59 - 66 Gpa, elongation rates in 5.4% - 20%. The forging procedure could increase the strength significantly but almost have no influence in elastic modulus of Ti-Nb-Zr. [ Conclusion] The Ti-Nb-Zr beta titanium alloys developed in our lab have lower modulus and high strength beth. It is a promising material for orthopedic implants.