At 1000 m/min, a catastrophic tool failure was observed in CC620 after 0.7 min of machining,Figure 7. In the same figure, CC650 continued with a gradual wear behavior approaching a tool lifeof 1.4 min. Figure 8 shows the SEM micrographs of the cutting tools after machining at 1000 m/min,illustrating a complete chipping of the cutting edge of CC620. In contrast, CC650 exhibited crater wear, and a small chipping area at the main cutting edge of the insert was present.