粉末冶金法合成高强低模超细晶医用钛合金

Fabrication of Biomedical Titanium Alloys with High Strength and Low Modulus by Means of Powder Metallurgy

为探寻有效的高强低模医用钛合金制备方法,采用机械合金化方法制备了不同Fe含量的(Ti69.7Nb23.7Zr4.9Ta1.7)100-xFex非晶/纳米晶合金粉末,随后采用放电等离子烧结-非晶晶化法得到了高强低模的超细晶钛基复合材料.结果表明:(1)机械合金化过程中,Fe含量对合金的非晶形成能力影响显著,文中实验条件下,只有当x增大至10时才能形成全非晶相的非晶粉末;(2)Fe含量也明显影响合成的块体钛合金的力学性能,合成的不同Fe含量合金中,只有(Ti69.7Nb23.7Zr4.9Ta1.7)94Fe6合金具有高强度和显著塑性,其压缩屈服强度为2425MPa,断裂强度为2650MPa,断裂应变为0.0691,平均弹性模量仅为52GPa,接近第三代生物医用钛合金的最低值.将所合成的超细晶钛合金与常用的两种生物钛合金(Ti-6Al-4V和Ti-13Nb-13Zr)进行抗摩擦磨损性能对比,发现所合成的钛合金具有最佳的耐磨性.

In order to explore an effective method to fabricate biomedical Ti alloy with high strength and low modu- lus, amorphous/nanocrystallized （Ti69 7 Nb23.7Zr4. 9Ta1. 7 ）100-xFex alloy powders with different Fe contents were syn- thesized via mechanical alloying, and, subsequently, uhrafine-grained Ti-based composites with high strength and low modulus were fabricated via the spark plasma sintering-amorphous crystallization. The results show that, during the performed mechanical alloying, Fe content significantly affects the glass-forming ability of the alloy system, con- cretely, fully amorphous structure forms only when x reaches 10; and that Fe content also has an obvious effect on the mechanical properties of the bulk composites, only the bulk composite at a x value of 6 possesses high strength and distinct plasticity, with the corresponding compressive yield stress, fracture stress and fracture strain respec- tively being 2425 MPa, 2650 MPa and 0. 0691, and with an average elastic modulus of 52 GPa that is close to the minimum of the third-generation biomedical Ti alloys. Moreover, by comparing the friction and wear properties of the fabricated composites with those of two kinds of conventional biomedical Ti alloys （Ti-6AL-4V and Ti-13Nb-13Zr）, it is found that the fabricated composites are of the best wear resistance.