Friction and Wear of Aluminum Alloy Reinforced by TiO₂ Particles

This composite has been developed by addition of 0.5 to 3.5 wt.% powders of TiO₂ to aluminum melt by semisolid-metal processing of aluminum alloy. Dry sliding wear behavior of pins of cast composite, fabricated by solidification of melt-particle slurry in mold, has been determined by pin-on-disk wear tests carried out conventionally and while removing wear debris by camel brush. The accumulated volume loss in composites increases linearly with increasing sliding distance and the wear rate increases more or less linearly with increasing load. Increasing particle content decreases wear rate at a given load. The accumulated volume loss is considerably higher when wear debris is removed by camel brush during dry sliding wear. The relatively brighter compacted oxide transfer layer could be observed in the SEM micrograph of worn pin surfaces of the composites developed by addition of TiO₂. At higher loads, the oxide debris are expected to get better compacted to form transfer layer, spread over a larger area of the sliding surface and thus, their removal causes a larger wear compared to that without removal of wear debris.