Wear behaviour of friction surfaced Al-Ni and Al-SiC coatings over mild steel

Abstract The friction surfacing (FS) method offers solid-state deposition of both identical and distinct coatings while avoiding a number of the issues that encompass the traditional fusion coating process. This study investigates FS for depositing aluminium based metal matrix composites (MMCs) onto AISI1018 mild steel substrates. The Al-2Si-15SiC and Al7075-15Ni MMC consumables used for the FS process were fabricated via stir casting. The FS process, optimized at 1200 rpm for Al-SiC and 1500 rpm for Al-Ni, resulted in refined microstructures and enhanced properties. Scanning electron microscopy (SEM) and energy dispersive x-ray analysis (EDAX) of the coating reveals surface with equiaxed and fine grains. The development of Al 3 Ni intermetallic compounds at the coating’s interface strengthens the bond by allowing the substrate and coating material to diffuse into each other. An excellent bonding strength of 147 MPa and 142 MPa is observed for the Al7075-15Ni and Al-2Si-15SiC coating deposits, respectively. In comparison to MMC consumable rods, the FS composite coating delivers 80%–85% reduction in grain size and enhances hardness. Vickers microhardness tests showed substantial hardness increases, with Al-Ni coatings reaching 183 HV. Wear tests indicated that Al-Ni coatings outperformed Al-SiC coatings and the steel substrate, exhibiting lower wear rates and friction coefficients. This research underscores FS’s effectiveness in improving the properties of aluminium MMC coatings on mild steel, with Al-Ni coatings showing exceptional wear resistance and bond strength for industrial applications.