Development of low elastic modulus titanium alloys forbone substitution

承载金属生物材料必须满足各种要求，如高机械强度、高耐腐蚀性和类似于活体皮质骨的低弹性模量。本研究制备了(Ti-60Zr)-X和(Ti-70Zr)-X(X=1at.%Pd或Pt)三元合金，并对其密度、杨氏模量、剪切模量、维氏硬度和晶体结构进行了分析。少量贵金属(Pd、Pt)的加入显著提高了材料的杨氏模量、剪切模量和维氏硬度。随着Pd和Pt的加入，密度也显著增加。X射线衍射研究表明，上述力学性能的显著变化是由于铸态合金铸锭中除ω相外还生成了α相所致。综上所述，从开发低弹模骨替代生物医用材料的角度来看，不建议在钛-锆合金中添加少量贵金属(Pd、铂)。

It is important for load-bearing metallic biomaterials to satisfy various requisites, such as high mechanical strength, high corrosion resistance and low elastic moduli similar to those of a living cortical bone. In the present study, (Ti-60Zr)-X and (Ti-70Zr)-X (X = 1 at.% Pd or Pt) ternary alloys were prepared and their density, Young’s modulus, shear modulus, Vickers hardness and crystal structure were analyzed. The addition of a small amount of noble metals (Pd, Pt) markedly increased Young’s modulus, shear modulus and Vickers hardness. Density also considerably increased with the addition of Pd and Pt. X-ray diffraction study showed that the above mentioned significant change in mechanical properties were caused by formation of a ω-phase in addition to α-phase in the as-cast alloy ingots. In summary, the alloying addition of a small amount of noble metals (Pd, Pt) to Ti-Zr alloys is not recommended from the viewpoint of the development of low elastic modulus biomedical materials for bone substitution.