Ti-10Mo-XNb合金铸态组织和机械性能的研究

为了研究Nb元素对Ti-10Mo合金组织和性能的影响,采用钨电极熔化、离心浇注工艺制备了4种钛合金(Ti-10Mo-XNb,X=0,3,7,10),分析并测试了Nb元素对Ti-10Mo合金铸态组织和力学性能的影响.研究结果表明:随着Nb含量的增加,3种Ti-Mo-Nb合金的铸态组织和相组成发生了改变,Ti-10Mo-3Nb合金由等轴的α+β晶粒组成,Ti-10Mo-7Nb合金由等轴的β晶粒组成,Ti-10Mo-10Nb合金由少量等轴和大量枝状的β晶粒组成.另外,随着Nb含量的增加,3种Ti-Mo-Nb合金的维氏硬度、压缩强度、弹性模量降低,压缩率和抗弯强度升高,压缩断口和弯曲断口由脆性断裂向韧性断裂转变.Ti-Mo-Nb合金有望成为新型的生物医用材料.

As-cast microstructure and mechanical properties of Ti-10Mo-XNb alloys

In order to study the effect of Nb on microstructure and mechanical properties of Ti-Mo-Nb alloys,four alloys (Ti-10Mo-XNb,X=0,3,7,10)were fabricated by using tungsten electrode melting and centrifugal casting. The effect of element Nb on the cast-microstructure and mechanical properties of Ti-10Mo alloy was studied. Results indicate that the as-cast microstructure and phase composition of Ti-Mo-Nb alloys have been changed with the increase of Nb content. Ti-10Mo-3Nb alloy is composed of equiaxed α+β crystal grains; Ti-10Mo-7Nb alloy is composed of equiaxed β crystal grains; Ti-10Mo-10Nb alloy is composed of few equiaxed and quite a few dendritic β crystal grains. With the increasing Nb content,the Vickers hardness,compression strength and elastic modulus are decreased,while the compression ratio and bending strength are increased. The analysis of fractographies shows that Ti-Mo-Nb alloy’s compression and bending fractures transform from brittle fracture to ductile fracture. Ti-Mo-Nb alloys offers potential advantages in biomedical applications.