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采用重力铸造制备Mg-2.2Nd-x Sr-0.3Zr(x=0,0.4和0.7,质量分数,%)镁合金。为使组织均匀,对铸态合金进行了固溶处理,并对固溶处理后的合金进行热挤压。采用光学显微镜和扫描电子显微镜观察合金的组织;采用失重、析氢和Tafel极化法分析合金在模拟体液中的生物腐蚀行为。研究结果表明:随着Sr含量的增加,固溶处理态合金中的残余共晶相增加,挤压后晶粒显著细化。3种腐蚀性能测试方法均表明固溶处理态合金的耐蚀性能随Sr含量的增加而显著降低,而挤压态合金的耐蚀性能随Sr的加入而提高。然而,Tafel极化法获得的挤压态合金的腐蚀趋势和其他2种方法获得的趋势不同。
Mg-2.2Nd-x Sr-0.3Zr (x = 0, 0.4 and 0.7, mass fraction,%) magnesium alloy was prepared by gravity casting. In order to make the organization uniform, the as-cast alloy was solution-treated and the solution-treated alloy was hot-extruded. The microstructure of the alloy was observed by optical microscope and scanning electron microscope. The biological corrosion behavior of the alloy in simulated body fluid was analyzed by weight loss, hydrogen evolution and Tafel polarization. The results show that with the increase of Sr content, the residual eutectic phase in the solution treated alloy increases and the grains after extrusion are significantly refined. The results of three kinds of corrosion tests show that the corrosion resistance of solution treated alloy decreases with the increase of Sr content, while the corrosion resistance of extruded alloy increases with the addition of Sr. However, the trend of corrosion of extruded alloys obtained by the Tafel polarization method is different from that of the other two methods.