高强度和低弹性模量Ti−Nb−Fe−Zr合金的显微组织和力学性能

Microstructure and mechanical properties of Ti−Nb−Fe−Zr alloys with high strength and low elastic modulus

将Zr添加到Ti−Nb−Fe合金中开发生物医用低模量、高强度β钛合金。采用电弧熔炼法制备Ti−12Nb−2Fe−(2,4,6,8,10)Zr(摩尔分数,%)铸锭,随后对其进行均匀化、冷轧和固溶处理。通过光学显微镜、X射线衍射和透射电子显微镜等技术分析合金的物相和显微组织。采用拉伸试验测定力学性能。结果表明,Zr和Fe在合金中具有显著的固溶强化效果,因此,所有合金的屈服强度和抗拉强度分别高于510 MPa和730 MPa。Zr对变形机制的影响较小,孪晶出现在所有变形合金中,且对强度和塑性有益。具有亚稳β相的Ti−12Nb−2Fe−(8,10)Zr合金表现出低弹性模量、高抗拉强度和良好的塑性,是生物医学植入物的合适候选材料。

Zr was added to Ti−Nb−Fe alloys to develop low elastic modulus and high strengthβ-Ti alloys for biomedical applications.Ingots of Ti−12Nb−2Fe−(2,4,6,8,10)Zr(at.%)were prepared by arc melting and then subjected to homogenization,cold rolling,and solution treatments.The phases and microstructures of the alloys were analyzed by optical microscopy,X-ray diffraction,and transmission electron microscopy.The mechanical properties were measured by tensile tests.The results indicate that Zr and Fe cause a remarkable solid-solution strengthening effect on the alloys;thus,all the alloys show yield and ultimate tensile strengths higher than 510 MPa and 730 MPa,respectively.Zr plays a weak role in the deformation mechanism.Further,twinning occurs in all the deformed alloys and is beneficial to both strength and plasticity.Ti−12Nb−2Fe−(8,10)Zr alloys with metastableβphases show low elastic modulus,high tensile strength,and good plasticity and are suitable candidate materials for biomedical implants.