Nd含量、固溶处理工艺对Mg-4Zn-xNd镁合金性能的影响

Effect of Nd Content and Solid Solution Treatment Process on Properties of Mg-4Zn-xNd Magnesium Alloy

采用重力铸造工艺制备了Mg-4Zn二元镁合金及不同Nd元素含量的Mg-4Zn-xNd(x=1,2,3)三元镁合金。对铸态合金先后在420℃(24 h)、510℃(4 h)工艺条件下进行固溶处理。通过显微组织观察、动电位极化测试、浸渍试验和体外细胞试验研究了Nd含量及固溶处理工艺对Mg-4Zn-xNd(x=0,1,2,3)合金的耐腐蚀性能及细胞相容性的影响。结果表明:稀土元素Nd的添加使合金晶粒尺寸减小,以及三元合金腐蚀速率降低;铸态合金经固溶处理后,基体中第二相含量明显降低,该三元合金的腐蚀速率降低;当Nd含量达到2 wt%时,Mg-4Zn-2Nd合金的耐腐蚀性及细胞相容性最好。

Mg-4Zn binary magnesium alloy and Mg-4Zn-xNd（x=0, 1, 2, 3） alloys with different Nd contents ternary magnesium alloy were prepared by gravity casting process. The cast alloys were solid solution treated at 420 ℃（24 h） and510℃（4 h）, respectively. The effects of Nd content and solid solution treatment process on the corrosion resistance and cytocompatibility of Mg-4Zn-xNd（x=0, 1, 2, 3） alloys were investigated by microstructure observation, dynamic potential polarization test, immersion test and vitro cell test. The results show the addition of Nd makes the grain refine and the corrosion rate of the ternary magnesium alloy decrease. Meanwhile, after the solid solution treatment of as-cast alloys, the content of the secondary phase in matrix decreases obviously, then, the corrosion resistance rate of the ternary magnesium alloy decreases by 40%. When the content of Nd reaches 2wt%, Mg-4Zn-2Nd alloy shows the best corrosion resistance and cytocompatibility.