Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 19 Special 3 December 2009|
（1. Zhuzhou Cemented Carbide Group Corp. Ltd, Zhuzhou 412000, China;
2. School of Metallurgical Engineering, Hunan University of Technology, Zhuzhou 412008, China）
Abstract:The variations of chemical compositions, phases, microstructure evolution and shrinking of cermets compact debinded in H2 or in vacuum and sintered subsequently in vacuum were studied systematically using chemical analysis, back scattering scanning electron microscopy (SEM), and X-ray diffractometry (XRD). The total carbon of cermets debinded in H2 is lower than that debinded in vacuum by 0.4%−0.5%. The contents of carbon and oxygen are decreased sharply when being sintered at 1 100−1 300 ℃. The decomposition reaction of nitrogen is conducted sharply at 1 300 ℃. However, the decomposition of nitrogen is inhibited while the liquid phase appears, and then begins again above 1 500 ℃. The solution reaction of TaC and Mo2C into ring phase starts at 1 200 ℃, and WC into ring phase at 1 300 ℃ is finished. Therefore, the heating rate during sintering of cermets between 900 ℃ and 1 350 ℃ is important.
Key words: Ti(C, N) cermets; sintering; composition; shrinkage; microstructure