WEAR AND WEAR TRANSITION MECHANISM IN SILICON-CARBIDE DURING SLIDING

Wear mechanisms in SiC during sliding have been investigated experimentally under paraffin oil lubrication. The wear and friction data indicate that a transition in wear mechanism occurs abruptly after a defined period of sliding. The transition point is reached earlier as load increases, Examination of wear samples reveals that surface material is predominantly removed by a plastic grooving process in the initial stage, and by a grain pull-out process after the transition. It is also observed that severe plastic deformation in the form of dislocations is produced during the sliding. The abrupt occurrence of the grain pull-out after a definite sliding time is discussed in relation to the internal stresses associated with this plastic deformation.