Microstructure evaluation and wear behavior analysis of FeCoNiCuAl particles reinforced aluminum matrix surface composites prepared using friction stir processing

Although aluminum alloy has excellent stiffness, formability, and specific strength, its poor wear resistance limits its wider application. In this study, FeCoNiCuAl particles reinforced aluminum matrix surface composites (AMCs) were prepared by friction stir processing (FSP). The effects of particles on the microstructure and wear behavior of AMCs were evaluated, and the wear resistance and wear mechanism of AMCs under different load conditions were studied. The particles in the AMCs were evenly distributed without agglomeration, and a diffusion layer containing Al2Cu intermetallic compounds was formed between the particles and the aluminum matrix. The microhardness of AMCs was approximately 95% higher than that of the base metal (BM). Under the load of 15N, the friction coefficient of the AMCs was the lowest, and the specific wear rate decreased by about 83% compared with that of the BM. The improvement of wear resistance of AMCs was mainly attributed to the barrier effect of the diffusion layer containing intermetallic compounds. As the wear load increased to 25N and 50N, the specific wear rate of AMCs increased. However, the friction coefficient showed a decreasing and then increasing trend compared to that at 15N, which was 0.21 and 0.23, respectively. According to the analysis, the increase in friction coefficient may be related to the fragmentation of the diffusion layer and the heat generation during the wear test. The FeCoNiCuAl particles reinforced AMCs fabricated by FSP exhibit good interfacial bonding and excellent wear resistance, providing a theoretical foundation for developing aluminum matrix surface composites with superior wear resistance.