Investigating wear behavior of Al/Al2O3/Gr hybrid composite prepared by centrifugal casting method

Hybrid composite of aluminum base reinforced with alumina and graphite particles was prepared by vortex casting method along with centrifugal casting and its tribological behavior was investigated. The wear test was performed with a sliding speed of 60 cm/s and a force of N30. The results showed that by adding graphite and alumina to the aluminum base, the abrasion resistance of the hybrid composite increased. The amount of graphite in the hybrid composite had a great effect on the wear rate, and adding it to an optimal amount leads to a decrease in the wear rate and its further increase leads to an increase in the wear rate. With the presence of alumina particles, the hardness decreased less and the wear resistance increased. The Al-Al2O3-Gr hybrid composite showed a much better wear rate than the base alloy as well as the Al-Gr composite. Al-Gr composite had a higher wear rate than the base alloy due to the high amount of graphite and the absence of alumina particles. The scanning electron microscope investigations of the wear surfaces showed that in the base alloy, the wear mechanism is a combination of adhesive, scraping, and indentation mechanisms, while in composites, the dominant wear mechanism is scratching and indentation.