Microstructure of Ti(CN)-WC-NbC-Ni Cermets

• Published in: Journal of the American Ceramic Society Vol. 84; no. 4; pp. 843 - 849
• Main Authors: Ahn, Sun-Yong, Kim, Seong-Won, Kang, Shinhoo
• Format: Journal Article
• Language: English
• Published: Westerville, Ohio American Ceramics Society 01.04.2001; Blackwell
• Subjects: Applied sciences; ceramic-metal systems; Exact sciences and technology; Metals. Metallurgy; microstructure; Powder metallurgy. Composite materials; Production techniques; Sintered metals and alloys. Pseudo alloys. Cermets; titanium carbonitride; Tungsten carbide; Niobium carbide; Cermet; Phase separation; Titanium Carbides nitrides; Nickel; Microstructure; Powder metallurgy; Lattice parameters; Dissolution
• ISSN: 0002-7820; 1551-2916
• DOI: 10.1111/j.1151-2916.2001.tb00750.x

An investigation of the microstructural evolution and dissolution phenomena in a Ti(C0.7N0.3)–xWC–yNbC–20Ni system is reported. In Ti(C0.7N0.3)–yNbC–20Ni systems, a phase separation occurs between the Ti(CN) core and the (Ti,Nb)(CN) rim phases when the system contains >15 wt% NbC. This phase separation results from the increased misfit between the cores and the solid‐solution rim phases with the addition of NbC. Based on data obtained from a previous study and compositional analyses of the rim structure of the Ti(C0.7N0.3)–yNbC–20Ni system, the average dissolution rates of WC and NbC appear to be approximately the same with respect to that of Ti(CN), under given sintering conditions (1510°C for 1 h). In addition, compositional changes in the rim structure of the Ti(C0.7N0.3)–xWC–yNbC–20Ni system are compared with those for a Ti(C0.7N0.3)–xWC–20Ni system to explain the effect of NbC on WC dissolution in the Ti(C0.7N0.3)–WC–NbC–Ni system. The presence of NbC in the Ti(C0.7N0.3)–xWC–20Ni system is found to suppress the dissolution of WC.