Wear behavior of Si3N4 ceramic cutting tool material against stainless steel in dry and water-lubricated conditions

Si3N4-based ceramic cutting tools have been used successfully for machining hard materials, like: cast irons, nickel based alloys etc. Austenitic stai nless steel AISI 321 is one of the most difficult-to-cut materials. In orde r to investigate the wear behavior of Si3N4 ceramic when cutting the stainl ess steel the wear tests were carried out on a pin-on-disk tribometer, whic h can simulate a realistic cutting process. The selected load range was fro m 58.8 N to 235.2 N, the speed range was from 0.8 m/s to 3.2 m/s. The exper iment results showed that the wear of Si3N4 ceramic increases with both loa d and speed. In dry conditions, the wear of ceramic is mainly caused by adh esion between the rubbing surfaces. In water-lubricated conditions, microfr acture of the ceramic may be increased due to stress corrosion of water to the ceramic surface, in addition, the wear is also attributed to adhesion a nd chemical action of water with the Si3N4 surface. Scanning electron micro scopy (SEM), electron probe microanalyzer (EPMA), Auger electron spectrosco py (AES) and energy dispersive X-ray analyzer (EDX) were used for examining of the worn surfaces. The wear mechanisms of Si3N4 ceramic sliding against the stainless steel were discussed in detail. (C) 1999 Published by Elsevi er Science Limited and Techna S.r.l. All rights reserved.