Thermodynamics of TiC- and Ti(C,N)-based cermet processing prior to liquid phase sintering stage

The thermodynamics of the various events occurring during heating to liquid phase sintering temperatures of powder compacts of TiC- and Ti(C,N)-based cermets has been investigated. The results show that via a series of dissolution, solute repartitioning and mixed rim formation reactions, Mo2C can not only help keep the systems free of oxides and residual oxygen but also moderate the Ti content in the Ni binder phase during the heating stage, thus prevent the formation of intermetallic compound and ensure good wetting in the subsequent liquid phase sintering stage.

Research highlights
► Thermodynamically feasible reactions of cermets at the heating stage of sintering.
► TiC or Ti(C,N) can be oxidized and form (Ti,Mo)C or (Ti,Mo)(C,N) rim.
► Mo2C can help keep the cermets free of oxides and residual oxygen.
► Mo2C can reduce Ti content in Ni binder and prevent intermetallic compound formation.