Preparation of ultra-fine TiC0.7N0.3-based cermet

Since ultra-fine Ti(C, N) has large surface and high activity, preparation of high performance cermets using ultra-fine Ti(C, N) powders is very difficult at the present. In the paper, deoxidation process of ultra-fine TiC0.7N0.3 powder is carried out firstly, and the oxygen content of ultra-fine TiC0.7N0.3 powder can be decreased from more than 1 wt% to 0.06 wt%; milling technology of ultra-fine TiC0.7N0.3-based cermet is studied in the paper, the results show that the optimum milling time is 45 h and the ball to powder weight ratio is 15:1, and the dispersant helps to achieve a homogeneous distribution of the ultra-fine powder; during vacuum sintering of ultra-fine cermet, pores tend to form, hence NT6B shows relatively lower properties than NT6A. After HIP process (1350 °C, 90 min, 70 MPa), the porosity can be largely decreased. The prepared ultra-fine cermet has typical core-rim microstructure, finer grain size and enhanced properties.