固溶处理对NQZ310K生物镁合金力学与腐蚀性能的影响

Effect of solution treatment on mechanical and corrosion properties of NQZ310K bio-magnesium alloy

为调控心血管支架用可降解镁合金的屈强比,对具有高屈强比的挤压态生物镁合金Mg-3.0Nd-1.0Ag-0.2Zn-0.4Zr(NQZ310K)进行了固溶处理,研究了固溶温度对合金显微组织、力学性能和腐蚀性能的影响。结果表明:随着固溶处理温度的提高,晶粒逐渐长大,屈服强度降低,而抗拉强度仍然保持较高水平,屈强比明显降低,加工硬化明显;与挤压态的腐蚀性能相比,固溶处理态合金在模拟体液中的腐蚀速率随固溶温度的升高而逐渐加快,腐蚀方式由均匀腐蚀转变为点蚀。

In order to regulate the yield ratio of bio-magnesium alloy for cardiovascular stent application, the as-extruded Mg-3.0 Nd-1.0 Ag-0.2 Zn-0.4 Zr(NQZ310 K) bio-magnesium alloy with high yield ratio was treated by solution treatment, and the effects of solution temperature on microstructure, mechanical and corrosion properties of the alloy were studied. The results show that with the increase of solution treatment temperature, the grain of the alloy grows gradually, the yield strength decreases, but the ultimate tensile strength remains a high level, the yield ratio decreases obviously, and the work hardening is remarkable. Compared with the corrosion performance of the as-extruded alloy, the corrosion rate of the solution treated alloy in simulated body fluid increases with the increase of solution temperature and the corrosion mode changes from homogeneous corrosion to pitting corrosion.