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设计了Mg-2.7Nd-0.2Zn-0.4Zr(质量分数,%)镁合金作为可降解生物医用材料。对固溶处理后的铸锭进行了热挤压处理,然后对挤压棒分别进行了时效处理、固溶处理及固溶+时效处理。利用光学显微镜和扫描电镜观察了合金的组织,测试了合金的室温力学性能,采用析氢和失重法测试了合金在模拟体液中的降解行为,用扫描电镜观察了降解产物形貌及洗去降解产物后的形貌。结果表明:固溶处理后合金的晶粒明显长大,固溶处理显著提高挤压态合金的伸长率,但降低了合金的强度,而时效处理可提高合金的强度,降低合金的伸长率;热处理可降低合金的屈强比。体外降解实验结果表明:固溶处理使合金的降解速率稍微加快,而时效处理则能稍微减慢合金的降解速率。
The Mg-2.7Nd-0.2Zn-0.4Zr (mass fraction,%) magnesium alloy was designed as biodegradable material. The hot-pressed cast ingot was treated by hot extrusion, and then the extruded bar was aged, solution treated and solution treated + aged. The microstructure of the alloy was observed by optical microscope and scanning electron microscope. The mechanical properties of the alloy at room temperature were tested. The degradation behavior of the alloy in simulated body fluid was tested by hydrogen evolution and weight loss methods. The morphology of the degradation product was observed by scanning electron microscopy. After the appearance. The results show that the grain size of the alloy increases obviously after solution treatment, and the solution treatment significantly increases the elongation of the extruded alloy, but decreases the strength of the alloy. However, the aging treatment can increase the strength of the alloy and reduce the elongation of the alloy Rate; heat treatment can reduce the alloy yield ratio. In vitro degradation experiments showed that: the solution treatment of the alloy slightly accelerated the rate of degradation, while the aging treatment can slightly slow down the rate of alloy degradation.