Effect of sub-micron Al2O3 concentration on dry wear properties of 6061 aluminum based composite

Dry wear tests of particle metal matrix composites (PMMC's) of the 6061 Al Alloy with sub-micron Al2O3 particles were performed using a pin-on-disc tribometer. The content of alumina in the composite was varied form 0 to 30%, (v/v), to study the effect of particles concentration on wear. The composites were prepared by powder metallurgy techniques. Tests were performed under different loads at room temperature (21 DGC), at constant sliding speed of 1 m/s. Results clearly indicate that increasing the volume percentage of alumina particles in the composite improves the wear resistance. Addition of 10%, (v/v), of alumina particles improved the wear resistance of the 6160 aluminium alloy by an average of 45% compared to the alloy. Increasing the alumina content to 20% improves the wear resistance by 113%. Further addition of alumina to 30% improves wear resistance by 145%. Hardness test indicate that the hardness of the composite also increases linearly with the percentage of added alumina particles. SEM tests revealed complex combination of wear mechanisms on the surface of the warn test specimens.