Wear of mixed alumina ceramic tools in high speed facing of Inconel 718

A study was undertaken to investigate the performance of mixed alumina ceramic tools in high speed facing of solution annealed Inconel 718. Machining tests were conducted using round inserts at cutting speeds ranging from 150 to 450 m/min. The feed rates ranged from 0.10 to 0.20 mm/rev and two depths of cut of 0.5 and 1.0 mm were used. The different tool failure modes, wear mechanisms, the effect of cutting speed, feed rate and depth of cut on the tool wear, tool life and cutting forces were studied. In addition the surface finish and residual stresses were also examined. Since ceramic cutting tools wear in an unpredictable pattern, a failure indicator that could be reliably applied has also been identified.