DRY SLIDING WEAR OF DISCONTINUOUSLY REINFORCED ALUMINUM COMPOSITES - REVIEW AND DISCUSSION

The dry sliding wear performance of discontinuously reinforced aluminum (DRA) as investigated by numerous Studies during the last two decades is reviewed and discussed. In general DRAs feature substantially better wear resistance than their respective unreinforced matrix. However, under particular conditions and wear mechanisms, the wear performance of the overall DRA-metal couple is similar to or lower than its respective unreinforced alloy-metal couple. Furthermore conflicting results regarding the effect of the different tribological parameters on the wear performance of DRAs are noted among the reviewed studies, thereby increasing the difficulty in achieving the optimization of DRA-metal couples. It is shown that parameter interactions exist and are responsible for these conflicting results. The development of a general framework identifying groups of interactive parameters and assessing wear material performance through investigating these groups of parameter is therefore presented. It is suggested that material loss can be rationalized from the understanding and description of the three wear precursors which delineate these groups of parameters, the wear precursors being surface, subsurface and third body behavior. It is proposed that optimization of a tribosystem can be done through optimizing the three behaviors independently, thus allowing consideration of a reduced number of parameters while providing a higher degree of practical extrapolation.