AbstractHigh wear resistance is an attribute frequently ascribed to metal matrix composites and is of clear importance to the designer is considering both the use of these materials in some applications and in selecting the machining processes which can be employed to fabricate components. Sliding wear of metal matrix composites is important wherever there is relative motion, either deliberate or unintentional. If hard particles are present in the system, for example, as contamination in a lubricant or intentionally in abrasive machining, then the abrasion resistance of the material may be relevant. This critical review considers the complex tribological behaviour of metal matrix composites with fibre, whisker, and particulate reinforcement. Under certain conditions, metal matrix composites show high wear resistance, but this is not always the case; an understanding of the fundamental mechanisms of wear is essential in order to use them more efficiently.MST/2057