Improvement to corrosion resistance of Ni–P coating on MAO magnesium alloy by BTESPT

Abstract

A layer of nickel–phosphorus alloy was electroless plated on the surface of microarc oxidised AZ31 magnesium alloy first, and then sealing treatment was performed on the electroless nickel plated coating using bis-(triethoxysilylpropyl)tetrasulphide silane. Fourier transform infrared spectroscopy, scanning electron microscope (SEM), energy dispersed X-ray spectroscope analyses, electrochemical techniques and immersion test were used for the analyses of surface morphology and structure and corrosion resistance of electroless nickel plated samples before and after sealing treatment. The results showed that the silane film by sealing treatment improves its corrosion resistance significantly.