Wear and mechanical properties of Al chips and Al chips composites recycled by high-pressure torsion

Pure Al chip, Al chip-20% Al₂O₃, and Al chip-20% SiC samples were recycled using high-pressure torsion (HPT). Influence of the HPT processing on the feasibility of the consolidation, the microstructure evolution, the hardness, and the wear properties of pure Al chip, Al chip-20% Al₂O₃, and Al chip-20% SiC samples were investigated and compared with those of the as-received Al and HPTed Al solid samples. The HPT processing successfully produces approximately fully dense ultrafine-grained (UFG) microstructure Al and Al composite samples with relative densities ranged from 99.7 to 98.3%. The HPT processing of the Al chip and Al chip composites samples effectively refine and fragmented the Al matrix and reinforcement particles, and so the hardness increases. The increase of the hardness enhances the wear resistance and frictional properties of the Al after recycling the Al chip and Al chip composites via HPT processing. The enhancement of the hardness and so the wear resistance affects the wear mechanism of the different samples. Worn surface morphology and analysis of the wear samples and WC ball and so support the wear and friction results.