Wear behavior of As-cast ZnAl27/SiC particulate metal-matrix composites under lubricated sliding condition

The wear behavior of a ZA27 alloy reinforced with various sizes of SiC particles is examined under lubricated condition. The severe wear of unreinforced ZA27 alloy at high applied load is mainly caused by the formation of deformed or surface mixed layer near the subsurface region. Wear can be markedly reduced by the addition of large sizes of SiC particles owing to the absence of a deformed layer. Depending on the initial state, a metal may undergo cyclic hardening or cyclic softening during fatigue process. The softening in the deformed layer of ZA27 alloy during lubricated wear tests may be associated with the fatigue fracture of surface asperities which may cause wear under well-lubricated conditions.