Abstract:The friction and wear properties of Mg₂B₂O₅ whisker reinforced 6061Al matrix composite fabricated via power ultrasonic-stir casting process were investigated using a ball-on-disk wear-testing machine against a GCr45 steel counterface under dry sliding conditions. The reinforcements include as-received Mg₂B₂O₅ whiskers and Mg₂B₂O₅ whiskers coated with CuO and ZnO. The volume fraction of the composites is 2%. The relationship between the wear rate and the coefficient of friction was discussed. The results indicate that the wear rate of the Mg₂B₂O₅ whiskers coated with ZnO reinforced aluminum matrix composites is the lowest among the materials. As the applied load and sliding speed steadily increase the coefficients of friction and wear rates of the as-received matrix alloy and the fabricated composites decrease. As the applied load and sliding speed increase, the wear mechanisms of the composites shift from a mild to a severe regime.

Key words: metal-matrix composite; sliding wear; wear testing; wear mechanism