Nb元素对Zr-Ti基生物材料力学性能和耐腐蚀性能的影响

通过真空非自耗电弧熔炼炉制备Zr-Ti-xNb(x=6、8、10,摩尔分数,%,下同)合金,采用锻造和β单相区固溶热处理工艺进一步加工铸锭,通过对材料微观组织、力学性能和耐腐蚀性能的表征,研究Nb元素对Zr-Ti基生物材料力学性能和耐腐蚀性能的影响。结果显示,Zr-Ti-xNb(x=6、8、10)合金均由β相和α″相组成,随着Nb元素含量增加,β相含量增加,α″相含量降低,Nb元素添加提高了合金中β相的稳定性。同时Nb含量增加,合金屈服强度由360 MPa增加至780 MPa,固溶强化效应明显,在变形过程中出现了应力诱发马氏体相变现象,极大提高材料的抗拉强度和塑性。同时可以较好地提高合金的耐腐蚀性能,实验表明三种材料在生理盐水中均表现出较强的耐腐蚀性能。

Effect of Nb on mechanical properties and corrosion resistance of Zr-Ti based biomaterials

In this paper,Zr-Ti-xNb(x=6,8,10,mole fraction,%)alloy is prepared via vacuum non-consumable arc melting furnace.Then the ingot is further processed by forging technology and heat treatment inβsingle-phase zone.The effect of Nb element on the mechanical properties and corrosion resistance of Zr-Ti based alloys was studied through the measurement of microstructure,mechanical properties and corrosion resistance.Zr-Ti-xNb(x=6,8,10)alloys are composed ofβphase andα"phase.When the content of Nb element increases,the content ofβphase increases,butα"phase content decreases,which indicates Nb improves the stability ofβphase.With the increase of Nb content,the yield strength raised from 360 MPa to 780 MPa.The solid solution strengthening effect is obvious.At the same time,stress induced martensitic transformation during the deformation process can greatly improve the tensile strength and plasticity.The increase of Nb content also enhances the corrosion resistance,and the experiments show that those alloys all exhibit strong corrosion resistance in physiological saline.