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采用光学显微镜(OM)、扫描电镜(SEM)、X射线衍射仪(XRD)及电化学工作站等设备,研究了固溶理对Mg-3.0Zn-0.6Y-0.5Zr-0.3Ca(质量分数,%)合金显微组织及生物腐蚀性能的影响。结果表明:铸态合金的显微组织由α-Mg枝晶、条状Mg_3YZn_6相和球状Ca_2Mg_6Zn_3组成。随着固溶温度(360~450℃)的升高,合金中的析出相逐渐溶解,同时,组织中有富Zr新相析出。电化学测试结果表明,合金经420℃×24 h固溶处理后,其腐蚀电位和腐蚀电流密度分别为-1.468 V和8.943μA/cm~2,显示出优异的耐蚀性能,这主要归因于低的第二相体积分数和细小的晶粒尺寸。
The effects of solid solution treatment on the microstructures and mechanical properties of Mg-3.0Zn-0.6Y-0.5Zr-0.3Ca (mass fraction, mass fraction, %) Alloy microstructure and the impact of biological corrosion. The results show that the microstructure of as-cast alloy consists of α-Mg dendrites, stripped Mg_3YZn_6 phase and spherical Ca_2Mg_6Zn_3. With the increase of solution temperature (360 ~ 450 ℃), the precipitated phase in the alloy gradually dissolves, meanwhile, the new Zr-rich phase precipitates in the microstructure. The results of electrochemical tests showed that the corrosion resistance and corrosion current density of the alloy after solution treatment at 420 ℃ for 24 h were -1.468 V and 8.943 μA / cm ~ 2, respectively, showing excellent corrosion resistance, mainly due to Low second phase volume fraction and fine grain size.