Effect of molybdenum content on the microstructure and mechanical properties of ultra-fine Ti(C, N) based cermets

Effect of molybdenum as a sintering aid on the microstructure and mechanical properties of Ti(C, N)–20WC–15Co–Mo–2.5C system cermets was studied in this work. Ti(C, N)-based cermets with variable Mo content were fabricated by conventional powder metallurgy techniques. The microstructure was investigated by means of X-ray diffractometer, scanning electron microscopy in combination with an energy dispersive spectrometer. Mechanical properties such as transverse rupture strength, fracture toughness and hardness were also measured, respectively. Results revealed that finer grains, as well as larger amount of bright core/grey shell structures could be obtained by increasing the molybdenum content. Transverse rupture strength and hardness were also improved. Fracture toughness, however, was decreased with the increase of Mo content. The optimized content of Mo was chosen as 15 wt.% for Ti(C, N)–20WC–15Co–Mo–2.5C system cermets.