Abstract:Orthogonal experiments were designed to investigate and to compare failure modes of the Al2O3/Ti(C, N) ceramic tool in intermittent turning of hardened steel in different cutting speed. The results show that the main tool failure modes are chipping and flaking at low speed, and fatigue failure of impact is small. With the increasing of cutting speeds, the influence of fatigue failure is gradually increased. At high speed, the main failure modes are fracture caused by fatigue crack propagation. Due to the difference of interior stress level of cutting tool at different cutting speeds, fatigue characteristics are differently shown because of the variation of crack propagation rate and direction. At lower cutting speed, the fatigue characteristic is shown fatigue striations, while the characteristic is fatigue curve at high cutting speed.