微量In对Mg-4Sn合金微观组织、电化学行为和放电性能的影响

Effect of Trace In on Microstructure,Electrochemical Behavior and Discharge Performance of Mg-4Sn Alloy

向铸态Mg-4Sn合金中添加1.0wt%In,研究了微量In对合金微观组织、电化学行为和放电性能的影响。结果表明,添加In元素前后,合金的微观组织均由树枝晶形态的α-Mg基体以及在枝晶间弥散分布的Mg_(2)Sn相组成。添加In元素后,In固溶于基体中,且合金的树枝晶尺寸变小,Mg_(2)Sn相的均匀性提高;合金的开路电位更负,自腐蚀电流密度更低;在电池性能的测试中,合金表现出更平稳的放电过程、更负的放电电位和更高的阳极效率。这主要归因于加入In后合金更高的放电活性和更疏松的放电产物。

1.0wt%In was introduced to Mg-4Sn cast alloy,and the effects of trace In on its microstructure,electrochemical property and discharge performance were studied.The result shows that the microstructure of the alloy before and after adding In element consists of dendriticα-Mg matrix and a small amount of Mg_(2)Sn phase scattered along grain boundary.After the addition of In,it dissolves into the matrix,and the dendritic crystal size decreases,the uniformity of Mg_(2)Sn phase improves,the open circuit potential of the alloy is more negative,the self-corrosion current density is lower.In the battery performance testing,the alloy with addition of In shows a smoother discharge process,more negative discharge potential and bigger anode efficiency.This ismainly attributed to the higher discharge activity and looser discharge products of the alloy after the addition of In.