Corrosion resistance of organic coating pretreated by phytic acid

摘要

In this study, phytic acid pretreatment is used as a substitute for toxic chromate pretreatment to improve the corrosion resistance of organic coating on AZ91D magnesium alloys. The microstructures of phytic acid conversion films are observed by a transmission electron microscope. The role of phytic acid pretreatment on the corrosion resistance of organic coating is investigated using salt spray test and electrochemical impedance spectroscopy. The experimental results show that the phytic acid conversion film exhibits a dense amorphous structure and phytic acid pretreatment can effectively improve the corrosion resistance of organic coating on magnesium alloys.