Abstract:
Si
3N
4 ceramic with mass fraction of 5% TiO
2 was prepared by gas pressure sintering and was made into a cutting tool. The effects of TiO
2 on its microstructure, mechanical properties and cutting performance were investigated, and compared with Si
3N
4 ceramic sintered without TiO
2. The results show that the sintered Si
3N
4 ceramic with TiO
2 was mainly composed of long rod-shaped and equiaxed β-Si
3N
4 grains, accompanied by uniformly distributed TiN phases. Compared with the sintered Si
3N
4 ceramic without TiO
2, the grains were refined, and the hardness increased while the fracture toughness decreased slightly. In the continuous cutting process of gray cast iron, Si
3N
4 ceramic cutting tool with TiO
2 had a longer cutting life (effective cutting length of 2 410 m) and maintained the integrity of the cutting edge, and had less adhesive wear debris after cutting.