Fig. 5 illustrates the evolution of flank wear as a function of cutting time at different cutting speeds and feed rates. This figure implies that with progression of cutting time, flank wear land increased. There are three distinct regions which can be seen in such wear curves. In the first region, the wear rate is relatively high due to wear of the tool layers damaged during manufacturing processes. The second region is the region of steady-state wear in which wear is uniform. In the third region of the wear curve, owing to high cutting forces, temperatures and severe tool vibrations, the tool wear rate is accelerated
Variation of cutting speed and feed rate affects the tool wear rate. As is depicted in Fig. 5, the increase of cutting speeds and feed rates led to a higher flank wear rate and consequently wear curves inclined to the left. This can be attributed to shorter contact area between chip-tool interface resulting in high concentration on temperature very close to the cutting edge