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

Abstract

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 ºC. When Co is used as the binder medium, it is possible to completely convert the starting commercial TiC-TiN mixture into TiC x N 1-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.

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

“…For Ti(C,N)-based cermets, the raw hard phases are comprised of binary hard compounds TiC and TiN or Ti(C,N) solid solutions, which provide high hardness [6,7]. The metal powders of Mo, Ni or Co are introduced as the binder, which can bond the ceramic phases and contribute to the ductility and toughness of cermets [8][9][10]. The secondary carbides such as Mo 2 C, WC, TaC or NbC are usually added to improve the sinterability, abrasion resistance or thermal shock resistance of cermets [4,[11][12][13].…”

Toughening of complete solid solution cermets by graphite addition

“…Typically, cermets consist of titanium carbide (TiC) or titanium carbonitride (Ti(C,N)) ceramic particles embedded in a Co/Ni metal alloy that acts as a binder [2][3][4][5]. Cermets combine the advantages of ceramics and metals [3]; the ceramic phase must mainly provide hardness and wear resistance, whereas the binder phase provides fracture strength and impact resistance [6].…”

Microstructure characterization and mechanical properties of Ti(C, N)-based cermets with AlN addition

“…There was only Ti(C, N) and Ni peaks in all four cermets. This implied that AlN, Mo, WC and Cr 3 C 2 completely dissolved into the binder phase or reacted with each other to form (Ti, W, Mo) (C, N) solid solutions known as rim phases [19]. Besides, neither graphite phase nor η phase which had harmful effect on the cermets was detected.…”