摘要
通过EPMA-1600电子探针对触变成形AZ91D镁合金在3.5%NaCl溶液腐蚀过程中表面主要合金元素浓度变化进行跟踪分析。结果表明:表面合金元素浓度的变化与合金元素所处的区域有关,在整个腐蚀表面上,Mg浓度随腐蚀的进行而降低,Al浓度升高;其中,原液相区Al浓度升高幅度最大。这是因为在β相(Mg17Al12)表面析出H2的扰动破坏了共晶α相表面腐蚀产物成膜的稳定性,使得共晶α相因无法得到腐蚀产物膜的保护继续腐蚀;Zn主要以固溶方式随β相凝固,作为腐蚀电池的阴极,在腐蚀过程中浓度基本不变化。
Tbe concentrations of surface alloy element of thixoformed AZ91D magnesium alloys in 3.5% NaCl solution was traced by EPMA-1600 electric probe. The results show that the concentration change of surface alloy elements is related with their regions. The concentration of Mg of all regions decreases with along the corrosion, that of Al is increases. In pre-liquids area, because the H2 gas liberated in 13（Mg17TAl12） phase destroys the stability of corrosion product films in eutectic α phase, the corrosion reaction is continued, the concentration of Al sharply increases. Zn is solidified with the β phase as solution, as the cathode of corrosion micro-cell, the concentration has no change.
出处
《热加工工艺》
CSCD
北大核心
2006年第8期18-20,24,共4页
Hot Working Technology
基金
中国-新西兰政府间国际科技合作项目(2002DFG00020)
863领域重点国际合作项目(2002AADF3303)
关键词
镁合金
触变成型
合金元素
magnesium alloy
thixoformed
alloy element
