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Precipitation Studies in the System WC‐Tic
Author(s) -
BRUN M. K.,
NEURGAONKAR R. R.,
STUBICAN V. S.
Publication year - 1975
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1151-2916.1975.tb19005.x
Subject(s) - materials science , tungsten carbide , solid solution , orthorhombic crystal system , carbide , precipitation , solubility , tungsten , crystallography , analytical chemistry (journal) , metallurgy , crystal structure , chemistry , physics , meteorology , chromatography
The solubility of WC in TiC was found to vary from 50 mol% at 2050°C to 75 mol% at 2350°C; WC was precipitated from solid solutions containing 75 mol% WC‐25 mol% TiC and 65 mol% WC‐35 mol% TiC at 1900°C. The precipitated WC occurred as well‐aligned ribbon‐shaped particles. The crystallographic orientation of the precipitate and the matrix established by electron diffraction techniques is [100] WC [110] TiC and [010] WC [001′] TiC . The interfacial planes were (001) for WC and (111) for TiC solid solution. Diffraction spot splitting occurred for all reflections of precipitated WC except the 001 type, indicating that compression of WC along the [110] direction took place, resulting in an apparent orthorhombic symmetry. This phenomenon was explained on the basis of the specific volumes and the difference in thermal expansion coefficient between WC and the solid solution. Tungsten carbide precipitated rapidly in the presence of Co, with all the WC precipitating in the form of platelets randomly oriented around the matrix grains. The hardness of the solid solutions 65 mol% WC‐35 mol% TIC and 75 mol% WC‐25 mol% Tic increased ∼10% and ∼23%, respectively, after they were annealed at 1900°C.