Wear properties of hybrid AlSi12 matrix syntactic foams

Hollow sphere reinforced aluminum matrix composites - so-called syntactic foams were produced by means of low pressure infiltration. Commercial AlSi12 aluminum alloy was applied as the matrix material. The overall volume fraction of the reinforcing iron (GM) and ceramic (GC) hollow spheres was maintained at similar to 64 vol.%, but their ratio was varied in 20 vol.% steps between 100 %GM-0 %GC and 0 %GM-100 %GC reinforcement composition. The wear properties of the produced specimens were investigated using the pin-on-disk method in dry and lubricated conditions. In the case of dry sliding conditions, the coefficient of friction increased with the ceramic reinforcement content. The pure iron reinforcement showed the lowest coefficient of friction and also the lowest wear rate. From the point of view of the worn surface, the full GC reinforcement was found to be the most promising with relatively smooth surfaces and low amount of wear debris. Based on the discussed results, aluminum matrix syntactic foams would be promising materials for moderately loaded sliding parts.