The demand for high performance alloy/metal matrix composite has increased for the applications where a relative motion between two bodies is dominant. In the present study, tribological characteristics of Al- 2 15%Si based alloy/composites reinforced with 10%Zn and 15%ZrO2 were investigated. Binary Al-15%Si alloy and Al-15%Si-10%Zn base matrix alloy were prepared by melting commercially pure Al, Si and Zn whereas Al-15%Si-10%Zn-15%ZrO2 composite was manufactured by the stir casting method. The dry sliding wear test was conducted in a Pin-on-Disc tester under different sliding velocities and loading conditions. Optical microscope and scanning electron microscope (SEM) with EDS were used for metallographic and wear behaviour analysis. The microstructure of the binary alloy consisted of block-like coarse primary Si and needle type eutectic Si phases randomly distributed in the α-Al dendrites. The microstructural examination of the ZrO2 reinforced Al-15%Si-10%Zn based composite revealed primary globular Si with a size between 25 µm to 75 µm; fragmented rod like eutectic Si phase and uniform dispersion of ZrO2 particles in aluminum. The results showed a reduction infriction coefficient and substantial enhancement in the hardness and wear resistance of the composite compared to the binary and base matrix alloys. The superior wear resistance could be due to a combined effect of solid lubrication provided by Zn and high fracture toughness and wear resistance by the ZrO2 particles. The predominant oxidative and abrasive wear were identified as the mechanisms that led to the material failure by the plastic deformation, and delamination
