Abstract: The poor wear and corrosion resistance of aluminum alloys has led to the easy failure of surface performance. In this work, composite coatings of TiC/martensitic stainless steel (TiC/MSS) on aluminum alloy are fabricated by a novel approach of circular oscillating laser for enhanced surface performance of aluminum alloys. The oscillation of laser leads to dense microstructure, and nano/micro scale TiC particles are formed simultaneously. The structure of coatings transforms from dendritic to ring-like with the addition of TiC, and the hardness of the substrate is increased by 4.5-7.8 times. The main wear form of coatings is adhesive wear. The refinement of microstructure and formation of multi-scale TiC have given rise to an increase in the resistance of the coating to plastic deformation, which reduces the degree of adhesion and improves wear resistance. Besides, the barrier effect of TiC particles to the electrolyte solution in the passive film gives rise to the drop in corrosion current density. The Cr-rich stacking faults can provide nucleation sites for the formation and growth of passive films with high continuity and stability, thereby improving the corrosion resistance of the coatings. The superior anticorrosion and wear resistance properties of the composite coatings in this work have emphasized the merits of oscillating laser in fabricating high-performance coatings and would enlighten the design of more advanced composite coatings.

Key words: Multi-scale TiC, Coating, Wear resistance, Corrosion resistance, Circular oscillating laser