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对铸态Mg-0.5Zn-0.4Zr-5Gd(质量分数,%)合金分别进行了固溶处理(T4)和固溶+时效处理(T6)。利用光学显微镜、X-射线衍射仪和透射电子显微镜研究了不同状态下合金的显微组织,采用静态腐蚀试验及电化学方法测试了不同状态合金在模拟体液中的耐蚀性,研究了固溶、固溶+时效处理对合金组织和耐蚀性的影响。结果表明,铸态Mg-0.5Zn-0.4Zr-5Gd合金的第二相主要为Mg3Gd和Mg5Gd相,合金经T4和T6处理后腐蚀速率降低,容抗弧半径增大,腐蚀电位Ecorr正移,腐蚀电流密度Icorr降低。其中合金经T6处理后其平均腐蚀速率为0.486 mm/year,腐蚀电位Ecorr较正,容抗弧半径较大,呈现出良好的耐蚀性。
The as-cast Mg-0.5Zn-0.4Zr-5Gd (mass fraction,%) alloy was treated by solution treatment (T4) and solution treatment + aging treatment (T6). The microstructure of the alloy under different conditions was studied by optical microscope, X-ray diffraction and transmission electron microscopy. The corrosion resistance of different alloys in simulated body fluid was tested by static corrosion test and electrochemical method. , The effects of solution treatment and aging treatment on the microstructure and corrosion resistance of the alloy. The results show that the second phase of as-cast Mg-0.5Zn-0.4Zr-5Gd alloy is mainly composed of Mg3Gd and Mg5Gd phases. After T4 and T6 treatment, the corrosion rate decreases, the arc radius increases, and the corrosion potential Ecorr moves forward. The corrosion current density Icorr decreases. Among them, the average corrosion rate of alloy after T6 treatment is 0.486 mm / year, the corrosion potential Ecorr is more positive and the capacitance arc radius is larger, showing good corrosion resistance.