Cutting performance and wear mechanisms of Sialon ceramic cutting tools at high speed dry turning of gray cast iron

In the present work, the phase composition and microstructure of two Sialon cutting inserts (named sample A and sample B) were characterized by XRD and SEM. The cutting performance and wear mechanism of the cutting inserts were investigated at high-speed dry turning of gray cast iron. The results showed that the main phases of them were α- and β-Sialon, and the sample A contained more α-Sialon than that of sample B. The grains of the Sialon cutting inserts are mainly elongated shape, and the aspect ratios are about 5.32 and 5.09, respectively. The tool life of sample B was longer than that of sample A at low speed. However, with the speeds increased, the tool life of sample A was getting closer to that of sample B and then exceeded that of sample B. The wear mechanisms of the two cutting inserts were abrasive and adhesive wear, however, as the cutting speeds increased, the dominant wear mechanisms were different.