摘要
采用光学显微镜、扫描电镜、盐水浸泡等方法研究了退火热处理工艺对Al/ZE42/Al复合板界面微观组织和该复合板在5.0%Na Cl(质量分数)水溶液中腐蚀行为的影响。实验结果表明:Al/ZE42/Al复合板经退火处理后,界面区域发生Mg和Al等元素的互扩散,界面扩散层包含2个反应层,靠近ZE42镁合金一侧的反应层为Mg_(17)Al_(12)相,靠近Al板一侧的反应层为Al_3Mg_2相,随着退火温度的升高或者保温时间的延长,ZE42/Al界面扩散层的厚度增加,ZE42镁合金发生了再结晶组织转变;退火热处理没有明显改善Al/ZE42/Al复合板的耐腐蚀性能,提高了腐蚀速率,其腐蚀机制为复合板边部向内部扩散而导致的电偶腐蚀加剧。
The microstructures and morphologies of Al/ZE42/Al composite plates were observed by optical microscopy（OM） and scanning electron microscopy（SEM）. Corrosion rates of the Al/ZE42/Al composite plates at different temperatures and held for different time were also measured in salt water immersion test, and the influence of annealing on interfacial microstructure of Al/ZE42/Al composite plates and corrosion behaviors in 5.0 wt% Na Cl aqueous solution were investigated. The results show that element diffusion of Mg, Al, Zn, Y and Er occur in Al/ZE42/Al composite plate interfacial region after annealing. The interfacial diffusion layer has two reaction layers. Mg_（17）Al_（12） phase is in one reaction layer near ZE42 magnesium alloy, while Al_3Mg_2 phase in the other reaction layer close to Al plate. With annealing temperature and holding time increasing, the thickness of ZE42/Al interfacial diffusion layer increases, and meanwhile recrystallization occurs in ZE42 magnesium alloy. Annealing cannot improve corrosion resistance of the Al/ZE42/Al composite plate, but it can increase corrosion rate. The corrosion mechanism of the Al/ZE42/Al composite plate is the aggravation of galvanic corrosion which occurs from edge to internal of the plate.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2016年第6期1571-1577,共7页
Rare Metal Materials and Engineering
基金
国家自然科学基金(51404137)
辽宁省重点实验室开放基金(2008329)
