摘要
为获得高强耐蚀的Mg-9Gd-4Y-1Nd-0.6Zr合金,采用光学显微镜、扫描电镜、透射电镜和电化学方法等分析了时效工艺对该合金强度和耐蚀性的影响。结果表明峰值时效合金强度很高但耐蚀性差,晶界析出相粗大且分布连续,在腐蚀溶液中镁合金由于析氢,晶界处很容易形成腐蚀通道。同时纳米尺寸的析出相和镁基体微电偶腐蚀很严重。过时效状态合金强度变化不大但耐蚀性显著增强,过时效样品晶内析出相粗大,晶界析出相分布不连续,腐蚀产物在其表面堆积导致腐蚀通道被堵塞,从而使合金耐蚀性显著提高。
To obtain high strength and good corrosion resistance of Mg-9Gd-4Y-1Nd-0.6Zr alloy,the effects of ageing on strength and corrosion resistance were investigated by means of optical microscopy,scanning electron microscopy,transmission electron microscopy and electrochemical methods.The results showed that the Mg alloy at peakaging conditions exhibited high strength but poor corrosion resistance.The precipitate particles at grain boundaries for the peak-aged samples were coarse and distributed continuously,which made corrosion channels could form easily when the Mg alloy evolved hydrogen in corrosion solutions.The nano-sized precipitates in the peak-aged samples could accelerate the micro-galvanic corrosion adjacent to the Mg matrix.Over-aged high strength Mg alloy has good corrosion resistance owing to the small discontinuously distributed particles at grain boundaries and the large precipitates in grains.The corrosion channels in the overaged Mg alloy were blocked by the discontinuous precipitates and corrosion products on its surface.
出处
《材料科学与工程学报》
CAS
CSCD
北大核心
2010年第4期490-493,504,共5页
Journal of Materials Science and Engineering
基金
国家安全重大基础研究资助项目(5133001E)
作者简介
作者简介：易建龙（1975-），男，湖南湘潭人，博士研究生，从事镁合金的腐蚀防护研究。E—mail：yijianlong@126．com。
