摘要
在50 g/L KMnO4和100 g/L Na3PO4组成的基础化学转化溶液中添加6 g/L缓蚀剂,在AZ31镁合金上获得了化学转化膜。用植酸作为转化处理液,分析了pH值、温度、转化时间及植酸用量(质量分数)对AZ31合金成膜及耐蚀性的影响,SEM观察表明,植酸膜经3.5%的NaC l溶液浸蚀后有一定的自愈合能力。这两种方法获得的转化膜均比铬酸膜光滑、致密均匀。
Chemical conversion coating was prepared on magnesium alloy substrate using aqueous solution of KMnO4 plus Na3PO4 containing NaNO3 inhibitor as the conversion liquid. At the same time, phytic acid was used as an environmentally friendly conversion agent to prepare conversion coating on the Mg alloy substrate as well. The morphologies and elemental compositions of the two types of chemical conversion coatings were analyzed by means of scanning electron microscopy and energy dispersive spectroscopy. The effects of pH value, temperature, conversion duration, and mass fraction of phytic acid on the morphology and corrosion resistance of the conversion coating were investigated, while the corrosion resistance of the types of chemical conversion coatings on Mg alloy substrate was compared. It was found that the two types of chemical conversion coatings on Mg alloy substrate were more smooth and compact than the chromale convention coating and had corrosion resistance comparable to that of the chromate convention coating. Moreover, the phytic arid conversion coaling mainly composed of phytate showed self-healing ability after being corroded in 3.5% NaCI solution.
出处
《材料保护》
CAS
CSCD
北大核心
2007年第1期10-12,共3页
Materials Protection
关键词
镁合金
化学转化膜
植酸
耐腐蚀性
magnesium alloys: chemical conversion coating
phytic acid
corrosion resistance
