Microstructure and Corrosion Behavior of Laser Cladding Al3Ti-Based Composite Coatings on AA6063 Aluminum Alloy
Intermetallic compound Al3Ti-based IMC coatings were formed on AA6063 aluminum alloy by laser cladding. The microstructure and corrosion characteristics in 3.5% NaCl solution were investigated. The results show that, the laser cladding coating is made up of Al3Ti dendrites, interdendritic α-Al and uniform distribution of TiC which hardly melted during laser irradiation, and shows good bonding to the substrate. The cross distribution of Al3Ti and α-Al helps to avoid the generation of cracks in the coating. The corrosion resistance of the laser cladding coatings is greatly increased as compared with the substrate, which owes mainly to the existence of hard Al3Ti and TiC. And with the increasing of TiC content in the coating, the corrosion resistance is improved simultaneously.