On the wear of aluminium and magnesium metal matrix composites

The effect of fibre reinforcement of aluminium, magnesium and Mg-9Al-1Zn on the wear properties has been investigated. Dry sliding, two- and three-body abrasion and solid particle erosion testing were performed. The results show that the tribological behaviour of metal matrix composites (MMCs) depends very much on the type of MMC and the type of contact situation, i.e. tribosystem. The dominant wear mechanisms are identified by light optical microscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy. In dry sliding an optimum wear resistance was obtained at a fibre content of approximately 10%. Magnesium and the magnesium alloy showed an increasing two-body abrasion resistance with increasing fibre content while no positive effects were observed in three-body abrasion. The abrasion rate of aluminium was not affected by the fibre content. In erosion, aluminium and magnesium displayed decreasing wear resistance with higher fibre content whereas the magnesium alloy was hardly affected. The relations between wear rate, wear mechanisms and matrix parameters are discussed.