Microstructural, mechanical and corrosion characterization of (C-HA)SiCnws coating on AZ31 magnesium alloy surface

Abstract

A composite coating was developed to address the issues of low binding force and poor wear resistance of the hydroxyapatite coating on the surface of magnesium alloy. The composite coating, known as (C-HA)SiCnws coating, was prepared on the surface of AZ31 magnesium alloy using the carbonation-oxidation method of phenolic resin and electrophoretic deposition. The (C-HA)SiCnws coating is composed of a carbon coating as the middle layer, a hydroxyapatite coating as the surface layer, and SiC nanowires that connect the carbon layer and the HA coating. The morphology and infrared spectrum of the coating were characterized, and tests were conducted to evaluate the adhesion, wear performance, electrochemical properties, and corrosion resistance of the coating. The results demonstrate that the (C-HA)SiCnws coating is uniform and flat. The adhesion of the coating, as determined by tensile, is 3.51 ± 0.54 MPa, which is 88 % higher than that of the pure HA coating. Furthermore, the wear performance of the (C-HA)SiCnws coating is excellent, with a wear rate of only 0.96 × 10−3 mm3/(N·m), representing a reduction of 68.2 %. Additionally, the (C-HA)SiCnws coating demonstrates a favorable corrosion protection effect in both electrochemical polarization and corrosion tests. Overall, the prepared (C-HA)SiCnws coating exhibits significant enhancements in terms of adhesion, wear resistance, and corrosion resistance.