Liquid-phase sintering of Ti(C,N)-based cermets. The effects of binder nature and content on the solubility and wettability of hard ceramic phases

Different commercial TiC–TiN/Co/Ni mixtures were used as raw materials for Ti(C,N) cermets, and the effects of the sintering parameters (binder content, binder nature, sintering time and additives) on the final hard ceramic phase were studied at the sintering temperature of 1400 °C. When Co is used as the binder medium, it is possible to completely convert the starting commercial TiC–TiN mixture into TiCxN1−x. When Ni is used, which exhibits lower solubilising capacity than Co, the total conversion can never be reached and the metallurgical reactions between TiC and TiN during the liquid-phase sintering are more dependent on the sintering time than on the binder content. However, the use of Co–Ni mixtures, showing a synergic effect between the wettability capacity of Ni and the solubilising capacity of Co, enhances the metallurgical reactions at short sintering times.

The research performed during this study provides a simple way to obtain a model for hightemperature metallurgical reactions between commercial TiC and TiN within a liquid-phase solvent medium (cobalt and/or nickel at 1400 °C). We have attempted to provide an indication of the roles of wettability and solubility during liquid-phase sintering.Figure optionsDownload as PowerPoint slideHighlights
► An indication of the roles of wettability and solubility during liquid-phase sintering is given.
► The greater solubilising capacity of Co when it is used as the binder medium enhances the metallurgical reactions.
► When Ni is used the reactions are more dependent on the sintering time than on the binder content.