Examination of the worn surface showed that wear in the baseline material involves significant amount of plastic deformation as indicated by material pile-up at the edge of track in Fig. 11b. SEM analysis indicates the wear mechanisms in the baseline material consist of abrasion, as shown by scratches in the direction of sliding, as displayed in Fig. 12a and fatigue as illustrated by cracks formation and material loss, as seen in Fig. 12b. In heat hardened flats, less plastic deformation occurred. There is no evidence of material pile-up at the edge and material removal occurred primarily by abrasion, as shown Fig. 12a. The increase in hardness is expected to reduce the amount of plastic deformation, which also reduces the extent of fatigue damage. Nonetheless, considerable amount of material removal did occur. In the FSP flat, minimal surface damage and material removal occurred. There were only a few scratches and minimal plastic deformation, as shown in Fig. 13. Indeed SEM analysis show occurrence of only superficial damage and material removal. An original grinding mark running across the wear track can still be clearly seen in Fig. 14; illustrating minimal material removal.