Hot pressing densification of WC-MoxC binderless carbide
(1. State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China;
2. Changsha Mining and Metallurgy Research Institute Co., Ltd., Changsha 410012, China)
2. Changsha Mining and Metallurgy Research Institute Co., Ltd., Changsha 410012, China)
Abstract: WC-6MoxC-0.47Cr3C2-0.28VC binderless carbide was prepared by hot pressing (1700 °C, 20 MPa). The sample was observed and analyzed by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffraction. The results show that during the hot pressing process, W atoms dissolve substantially into the MoxC crystal lattices; whilst, the reverse dissolution of Mo atoms into the WC crystal lattices takes place. Consequently, the main phase and binder phase structure are formed. The phase compositions of the main phase and binder phase are a WC-based solid solution containing Mo and a Mo2C-based solid solution containing W, respectively. The isotropic dissolution and precipitation of W and Mo atoms do not result in substantial carbide coarsening. The mechanism for the densification was discussed.
Key words: binderless carbide; hot pressing; diffusion behavior; densification; grain growth; WC-MoxC