Effect of Mo Content on the Microstructure and Mechanical Properties of Tic Steel Bonded Carbide

The effect of Mo content on microstructure and mechanical properties of TiC steel bonded carbide was investigated when Mo content was 0.6%, 1.25%, 2% and 2.5% respectively. Results showed that density, hardness and transverse rupture strength of the sintered material achieved the best combined values when Mo content was 1.25%. At this point, the sintered density reached 98.56% theoretical density, the hardness is 64.2HRC, and the transverse rupture strength in sintering and heat treatment states was 1532MPa and 2274MPa respectively. When Mo content is more than 1.25%, grains of the hard phase grew up clearly and brittleness of the sintering material increased because of the bigger thickness of (Ti, Mo) C solid solution layer generated on the surface of TiC phase, resulting in severe deterioration of mechanical properties of the sintered material.