The microstructure and mechanical properties of a new-type of cermets cutter （ tool A ） with nano- TiN modification and its cutting properties in cutting gray cast iron are investigated. SEM and TEM observatioas of the microstructure of the above material reveal that nano- TiN modified cermets possess a finer microstructare than conventional cermets. In the cutting tests, for comparison, cemented carbide cutter （ YG8, tool B） was also utilized. The cutting results show that the cutting properties of tool A are superior to those of tool B. It is also Jound that the predominant failare mode of tool A is normal wear and micro-spalling under lower cutting quantities, and that chipping occurs under higher cutting quanthies . SEM analysis reveals that cohesion, oxidation and diffusion wear become very apparent at a higher cutting speed. On the contrary, grain wear also exists but is not apparent.
