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 observations of the microstructure of the above material reveal that nano-TiN modified cermets possess a finer microstructure 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 found that the predominant failure mode of tool A is normal wear and micro-spalling under lower cutting quantities, and that chipping occurs under higher cutting quantities. 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.
研究了Mo添加量对铣削用TiC TiN(nm)WC-Mo2C Ni Co金属陶瓷的组织特征、力学性能和断口形貌的影响。结果表明,金属陶瓷的组织为典型的两相结构特征,其中陶瓷相的芯/壳结构(core/rimstructure)与溶解析出机制有关。少量Mo的加入能提高材料的力学性能。断口SEM分析表明:断裂机理为典型的混合型断裂(穿晶断裂和沿晶断裂),金属相存在着明显撕裂的痕迹。
