凝固速度对Mg-Hg阳极材料组织及性能的影响  

Effects of cooling rate on microstructures and electrical properties of Mg-Hg anode material

作　　者：余琨[1] 黎文献[1] 王日初[1] 巢国辉[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《材料科学与工艺》2009年第3期347-350,共4页Materials Science and Technology

摘　　要：Mg-Hg合金是一种海水激活动力电池阳极用材料,为提高海水激活电池的各项电化学性能,采用金相显微组织观测、扫描电镜形貌和成分分析、恒电流放电测量电位等方法,重点研究了Mg-6.4%Hg合金在不同凝固冷却速度下,合金显微组织的变化和放电性能的变化.结果表明:合金中的第二相为Mg3Hg相,随炉冷却和铁模空冷铸造合金中,Mg3Hg相分布在晶界上,而采用水冷模铸造时,Mg3Hg相在晶界和晶内同时析出.Mg3Hg相在晶界析出的情况下,发生电化学反应时容易集中溶解,对镁的氧化膜破坏作用很大,对合金的活化作用增强,造成了合金平均电位负移.当冷却速度增加后,Hg在α(Mg)基体中的固溶度增加,使其活化作用不如在晶界析出大,因此,合金平均电位负移较少.To improve the electrochemical properties of battery, property of Mg - 6. 4% Hg alloy at different solidification cooling the changes of mierostructure and discharge rates were investigated by metallurgical microscopy, SEM, composition analysis and constant-current discharge method. Results show that the second phase Mg3 Hg is a main compound in the alloy that influences the electric properties of alloy. In furnace cooling and air cooling in Fe mould, the Mg3 Hg compound precipitates on the boundary of grains, which improves the activity of Mg matrix and leads to negative voltage of the anode material. In water cooling, the Mg3Hg phase becomes a solid solution in Mg and leads to positive voltage. Thus the Mg - Hg alloy does not exhibit polarization and can be used as adequate anode material for sea water active battery.

关 键 词：镁合金 阳极材料 动力电池 冷却速度 

分 类 号：TG146.2[一般工业技术—材料科学与工程]