Fabrication and properties of Ti(C,N) based cermets reinforced by nano-CBN particles

摘要

Titanium carbontride (Ti(C,N)) based cermets with and without nano-cubic boron nitride (CBN) particles were prepared by microwave sintering in argon and nitrogen environment, respectively. Two kinds of core-rim microstructure, black core-grey rim and white core-grey rim, are shown in the cermets by scanning electron microscopy (SEM) in combination with energy dispersive X-ray analysis (EDX). It is found that, for the cermet with 1.5% nano-CBN particles sintered at 1500 °C for 30 min in argon, its transverse rupture strength (TRS) and hardness are improved to about 25.9% and 1.4%, respectively. The SEM analysis shows that the inhibition effect of nano-CBN particles on the dissolution of Ti(C,N) is weakened with the increase of content of nano-CBN particles. Moreover, for the cermet sintered in argon reinforced by 1.5% nano-CBN particles, more fine black core-grey rims are found in the microstructure compared to the others. For the material sintered in nitrogen, its microstructure accompanied with many white core-grey rims in number and big black core and thin outer rim in size, results in high hardness and low TRS.