Study on the formation of core–rim structure in Ti(CN)-based cermets

Effects of metal binder on the microstructure and mechanical properties of Ti(C,N)-based cermets

“…The results of EDS analysis indicate that the black cores were the undissolved Ti(C,N) particles containing more Ti, N and C atoms. The rim phases were (Ti,W,Mo)(C,N) solid solutions which were rich in heavy elements of Mo and W, and the binder phases surrounding the Ti(C,N) grains had higher contents of Ni, Co, Mo and W. Ostwald's dissolution-precipitation theory [19,20] revealed that the WC and Mo 2 C grains dissolved in the binder and formed the rim phase with Ti(C,N) through the elements diffusion and the dissolved carbides precipitation during solid sintering and liquid sintering, respectively. As depicted in Fig.…”

Effect of heating rate on the mechanical properties and microstructure of Ti(C,N)-based cermets

“…According to Ostwald's dissolution-precipitation theory [16][17][18], during the sintering of Ti(C,N)-based cermets under the temperature above 1300 1C, the WC and Mo 2 C powders dissolved into the binder phases and precipitated the rim phases of (Ti,W, Mo)(C,N) solid solution on the Ti(C,N) particles. The black cores were the undissolved coarse Ti(C,N) particles, and the white cores were the dissolved fine Ti(C,N) particles.…”

Effect of Mo2C/(Mo2C+WC) weight ratio on the microstructure and mechanical properties of Ti(C,N)-based cermet tool materials

“…During sintering, the secondary carbides of Mo 2 C and WC dissolved in binder phases and disappeared completely at 1150 C and 1300 C, respectively [29]. Meanwhile, the fine Ti(C,N) particles dissolved and the coarse particles remained.…”

“…Thus, the Cermet A-0.2 obtained coarse grains with well developed and thickened rims and large binder mean free path. In addition, when the Mo 2 C/(Mo 2 C þ WC) ratio increased, because of the lower dissolution temperature of Mo 2 C at 950 C than that of WC at 1150 C [29], the added Mo 2 C first formed solid solutions on Ti(C,N) particles through solid solution reaction. This suppressed the dissolution of Ti(C,N) particles and improved the wettability between hard phases and metal phases.…”