稀土元素Dy对Mg-2Zn-0.5Zr生物镁合金组织与性能的影响

通过拉伸试验、浸泡实验、电化学测试、扫描电镜(SEM)以及光学显微镜(OM)等方法研究了Dy含量对Mg-2Zn-0.5Zr-xDy生物镁合金微观组织、耐腐蚀性能和力学性能的影响。结果表明:随Dy含量的增加,合金的晶粒尺寸逐渐变小,第二相逐渐增多且主要沿晶界分布,合金的平均腐蚀速率先降低后升高,合金的力学性能先升高后降低;当Dy含量为1.5 mass%时,合金的耐蚀性能和综合力学性能均最好,平均腐蚀速率从未添加稀土元素时的1.28 mm/a降为0.92 mm/a,抗拉强度和伸长率分别为154 MPa和8.6%。

Effect of rare earth element Dy on microstructure and properties of Mg-2Zn-0.5Zr bio-magnesium alloy

Effects of rare earth element Dy content on microstructure, corrosion resistance and mechanical properties of Mg-2 Zn-0.5 Zr-xDy biological magnesium alloy were studied by means of tensile test, immersion test, electrochemical test, scanning electron microscopy(SEM) and optical microscope(OM). The results show that with the increase of Dy content, the grain size of the alloy decreases gradually, and the second phase increases gradually and distributes mainly along the grain boundary, the average corrosion rate of the alloy decreases at first and then increases, and the mechanical properties of the alloy increase at first and then decrease. When the content of Dy is 1.5 mass%, the corrosion resistance and comprehensive mechanical properties of the alloy are the best, and the average corrosion rate decreases from 1.28 mm/a(without Dy addition) to 0.92 mm/a(with 1.5 mass%Dy addition), the tensile strength and elongation of the alloy are 154 MPa and 8.6%, respectively.