Surface modification on AZ31B Mg alloy for improved corrosion resistance and hardness by thermal spray aluminium coating

Abstract

The recently developed thermal spray technique was used to deposit different composition of totally dense aluminium-based (Al) coating on AZ31B magnesium (Mg) alloy. The microstructure, adhesive coating, and corrosion behaviour of the materials were all thoroughly examined. The Al-coated AZ31B alloy has enhanced surface morphology and mechanical characteristics. This exceptional corrosion resistance is due to its disordered structure, consistent material composition, and the creation of a uniform passive coating on the surface, which prevents chloride ions from invading and causing additional corrosion. The high defined corrosion tests also show that the Al-based coatings are not aqueous solution permeable for the certain period immersions, indicating that the AZ31B Mg alloy substrate was protected against corrosion for a long time. Furthermore, the differences in corrosion resistances of Al-based coating was detected and explained using their distinct microstructures created during the coating deposition process. The current thermal spray technique has a lot of potential for cost-efficient and effective magnesium alloy corrosion protection, and it gives industries greater freedom in designing and using magnesium alloy products.