Ca含量对AZ61-1.2Y镁合金耐蚀性能的影响

Effect of Calcium Content on Corrosion Resistance of AZ61-1.2Y Magnesium Alloys

摘要:

利用静态失重法研究了不同Ca含量对AZ61-1.2Y镁合金腐蚀速率的影响。用金相显微镜、扫描电子显微镜观察试样的微观组织、表面腐蚀形貌。结果表明，添加1%的Ca(质量分数，下同)时，合金的晶粒得到了明显的细化，组织和成分更加均匀；当Ca含量大于1%时，合金的析出相增多，并产生粗化、偏聚的现象。在两种浓度的腐蚀介质中（0.5%和3.5%的NaCl水溶液），合金的腐蚀速率均随着Ca含量的增加呈现先减小后增大的趋势，其中当Ca含量为1%时合金的腐蚀速率均达到最低，耐蚀性能得到明显的改善。

Abstract:

Effect of calcium content on corrosion rate of AZ61-1.2Y magnesium alloys in 0.5% and 3.5% NaCl solution was studied by the static mass-loss tests. The microstructures of the alloys were observed by optical microscope and the morphologies of corrosion surface were analyzed with scanning electron microscopy. The results indicate that with the addition of 1wt% calcium, the grain size of the AZ61-1.2Y alloys is obviously refined, and the microstructure and component is more homogeneous. But when the addition of calcium is more than 1wt%, the precipitates of the alloys increase and they cause the phenomenon of coarsening and segregation. Furthermore, in 0.5% and 3.5% NaCl solution, the corrosion rates of the alloys decrease firstly and then increase with the increase of calcium content. With the addition of 1wt% calcium, the corrosion rate of the alloys is lowest, and the corrosion resistance is improved remarkably.