(1. 河南科技大学 材料科学与工程学院，洛阳 471023；
2. 有色金属共性技术河南省协同创新中心，洛阳 471023)
摘 要: 采用金相显微镜(OM)、扫描电镜(SEM)、透射电镜(TEM)研究固溶处理温度对Mg-2.0Zn-0.5Zr-3.0Gd(质量分数，%)生物镁合金显微组织的影响，通过失重、析氢和电化学方法研究合金在模拟体液(SBF)中的耐腐蚀性能。结果表明：铸态合金中，第二相(Mg, Zn)3Gd在合金基体中呈网状分布。固溶处理温度在460~500 ℃时，合金的晶粒尺寸随温度的升高而逐渐增大，温度为480 ℃时，没有溶入基体的(Mg, Zn)3Gd相以颗粒状或长条状的形式存在于基体中，部分颗粒与α-Mg基体具有共格关系。随着固溶处理温度的升高，合金的腐蚀速率先减小后增大，固溶处理温度在480 ℃时，合金的耐腐蚀性能比铸态合金的有了较大的提高。在120 h的浸泡实验中，合金的腐蚀速率在最后24 h时逐渐趋于稳定。
关键字: 镁合金；微观组织；生物腐蚀性能；电化学性能
（1. School of Materials Science and Engineering, Henan University of Science and Technology, Luoyang 471023, China;
2. Collaborative Innovation Center of Nonferrous Metals, Luoyang 471023, China）
Abstract:The effects of temperatures on microstructure of Mg-2.0Zn-0.5Zr-3.0Gd magnesium alloy were investigated by metallographic microscope (OM), scanning electronic microscope (SEM), transmission electron microscope (TEM). The corrosion properties of magnesium alloy were studied by mass loss, hydrogen evolution and electrochemical tests in the simulated body fluid (SBF). The results show that the second phase (Mg, Zn)3Gd is network distributed in the alloy matrix for the as-cast alloy. The grain size of alloy gradually increases with the increase of solid solution temperature at a temperature range of 460-500 ℃. There is no dissolved (Mg, Zn)3Gd phase present as a strip and particle form in alloy matrix when the temperature is 480 ℃. While partially granular phase has coherent interface relationship with α-Mg matrix. The corrosion rate for the solid solution alloy decreases with the increase of the solid solution temperature, and then increases. The corrosion resistance of the alloy is better than that of the as-cast alloy when the solid solution temperature is 480 ℃. In the immersion test of 120 h, the corrosion rate of alloys gradually reaches a steady state value in the last 24 h.
Key words: magnesium alloy; microstructure; biocorrosion property; electrochemical property
