Fabrication of superhydrophobic needle-like Ca-P coating with anti-fouling and anti-corrosion properties on AZ31 magnesium alloy

摘要

The poor corrosion resistance of magnesium (Mg) alloys limits their applications, and preparing the superhydrophobic coating with a facile and cost-effective method is meaningful for anti-corrosion protection of Mg alloys. In this work, a superhydrophobic needle-like Ca-P coating was fabricated on AZ31 substrate by a chemical conversion method and low energy modification with stearic acid. The water contact angle of the obtained coating was about 158.7? and the sliding angle was 1.5?. Due to the stable superhydrophobicity and durability of the coating, it can not only resist the pollution of muddy water and particulate contaminants, but also withstand the destruction of high temperature and external mechanical force. And the anti-fouling ability of the coating was evaluated from the force model of the contamination. In addition, the electrochemical measurements indicated that the superhydrophobic sample exhibited excellent anti-corrosion performance in Hank?s solution, and the coating could behave as the protective barrier to the substrate. Therefore, the anti-fouling, robust and corrosionresistant superhydrophobic coating has significant advantages in the protection of Mg alloys.