1. Combined effect of SiC and carbon on sintering kinetics, microstructure and mechanical properties of fine-grained binderless tungsten carbide
- Author
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Lantsev, E. A., Andreev, P. V., Nokhrin, A. V., Blagoveshchenskiy, Yu. V., Isaeva, N. V., Boldin, M. S., Murashov, A. A., Shcherbak, G. V., Smetanina, K. E., Chuvil'deev, V. N., and Tabachkova, N. Yu.
- Subjects
Condensed Matter - Materials Science - Abstract
The study investigates the density, phase composition, microstructure and mechanical properties (microhardness, fracture toughness) of binderless WC + SiC and WC + SiC + C ceramics obtained by Spark Plasma Sintering (SPS). Nanopowders of a-WC produced by DC arc plasma chemical synthesis were used as raw materials. Powder compositions for sintering contained graphite (0.3, 0.5% wt.) or b-SiC (1, 3, 5% wt.) with 0.3% wt. graphite. It was shown that WC + 1% wt. SiC + 0.3% wt.C ceramics have a homogeneous fine-grained microstructure, high relative density, increased microhardness and Palmquist fracture toughness (Indentation Fracture Resistance). The kinetics of the initial sintering stage of WC + C and WC + C + SiC powder compositions was also analyzed using high-temperature dilatometry at the conventional pressureless sintering (CPS) conditions. The CPS and SPS activation energies of WC + SiC powder at the intensive shrinkage stage were determined using the Young-Cutler model. The CPS activation energies of WC, WC + C and WC + C + SiC powder compositions are close to the activation energy of diffusion of the carbon C along the a-WC grain boundaries. The SPS activation energies of WC + C and WC+ C + SiC powder compositions turn out to be lower than the activation energy of the C of a-WC grain boundary., Comment: 35 pages, 3 tables, 18 figures, 40 references
- Published
- 2023