摘要
采用HNO3-KMnO4对AZ91D镁合金进行化学转化表面处理,获得了锰酸盐膜,利用中性盐雾试验和极化曲线法测试了转化膜的耐蚀性,使用划格法测试了转化膜与有机涂层的附着力,采用扫描电镜、能谱仪分析了转化膜的微观形貌、成分和结构并讨论了成膜机理。结果表明,当KMnO4的质量浓度为3.5g/L、pH值为4.0、处理温度为40℃、处理时间为120s时,膜层耐蚀性最好。该膜层为黄色颗粒团簇状,主要由Mn的氧化物等组成,耐蚀性高于基体,对铁红漆的附着力达到了3B级。
The permanganate conversion coating on AZ91D magnesium alloy was prepared in a nitric acid-permanganate solution, and the corrosion resistant of the coating was examined by neutral salt spray testing(NSS) and polarization curves, and the adhesive forces of the conversion coating to organic coating were measured by lattice method. Meanwhile, the microstructure, constituent, structure and forming mechanism of the conversion coating were determined by SEM (scanning electron microscope), EDS and XRD. It is found that the desirable corrosion resistance of the conversion coating that exhibits yellow and appears as cluster particles like deposits and is composed of Mn oxide can be observed at temperature of 40 ℃ for 120 s in 3.5 g/L KMnO4 solution with pH value of 4.0, which is greatly superior to that of the magnesium alloy substrate. In addition, the adhesive grade to iron red paint reaches up to 3B.
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2008年第10期798-800,共3页
Special Casting & Nonferrous Alloys
基金
南京工程学院科研基金资助项目(KXJ07009)
关键词
镁合金
转化膜
高锰酸盐
耐蚀性
Magnesium Alloy, Chemical Conversion Coating, Permanganate, Corrosion Resistance
