Thermodynamics of the formation of contiguity between ceramic grains and interface structures of Ti(C,N)-based cermets

The contiguity of carbide crystals in cermets is analyzed in this paper. The purpose of the paper is to present a thermodynamic analysis of the formation of contiguity of carbide grains in Ti(C,N)-Ni cermets. An equilibrium contiguity equation is built which shows that contiguity is retained in grades of high nickel contents. Although some elements such as Mo can reduce the contiguity, they cannot make the contiguity equal to zero. The valence electron structure analysis indicates that the same crystal surfaces (h k l)Ti(C.N) will tend to contact each other, but just the (1 1 0)Ni of the metal phase can match with (1 1 0)Ti(C,N) to form a stable interface (1 1 0)Ni/(1 1 0)Ti(C,N).