Interface study for the design of alternative matrixes in cermets

One of the main topics of current research in the field of TiCN-based cermets is the development of alternative metallic matrixes to conventional ones which have in their composition Ni and/or Co. The feature that must fulfill an alternative matrix is to achieve similar or even higher properties to those obtained with conventional matrixes using more economical and harmless materials. Furthermore, it should be taken into account the high temperature behavior of the liquid metallic matrix on TiCN reinforcement due to their processing is performed by Liquid Phase Sintering (LPS).

The study of the high temperature interaction in terms of wettability and solubility of the metallic matrix on the ceramic reinforcement should be performed systematically in this type of composite materials due to is the key to achieve good densification and sinterability.

In this work it has been performed the study of the liquid phase formation and its interaction with the TiCN reinforcement of a conventional metallic matrix (Ni), the main candidate as alternative matrix (Fe) and a Ni-Fe matrix. This study has been developed by high temperature wetting experiments in which liquid phase formation and contact angle between phases is monitored. The observed wetting behavior is explained by studying the solubility at the interface which is accomplished by compositional analysis and by kinetic simulation. Results allow explaining the final properties of the sintered cermet and the differences found using an alternative metallic matrix.