Performance of Whisker-Reinforced Ceramic Tools in Milling Nickel-Based Superalloy

This paper investigates failure characteristics and cutting performance of silicon carbide whisker-reinforced ceramic tools during milling of Inconel 718. Cutting tests were performed using round and square inserts, at cutting speeds ranging from 200 to 700 m/min. and feeds from .05 to .15 mm/tooth. Various immersion ratios were also considered. Tool wear was examined under the various cutting conditions. The behaviour of the cutting forces and temperatures during machining were then examined.The results show that an improved performance was obtained using the round inserts in comparison with the square ones. Modes of tool failure were found to be depth of cut notch wear and trailing edge wear. The former wear was dominant at cutting speeds from 200 to 400 m/min, while the later wear was dominant at speeds from 400 to 700 m/min. Flank wear was mainly due to adhesion of workpiece material on the tool surface. The best performance was achieved at a speed of 700 m/min, feed of 0.15 mm/tooth and 1.25 mm depth of cut.