Details

Autor(en) / Beteiligte

• Lonergan, Jason M.
• Fahrenholtz, William G.
• Hilmas, Greg E.
• Lee, W.

Titel

Sintering Mechanisms and Kinetics for Reaction Hot-Pressed ZrB2

Ist Teil von

• Journal of the American Ceramic Society, 2015-08, Vol.98 (8), p.2344-2351

Ort / Verlag

Columbus: Blackwell Publishing Ltd

Erscheinungsjahr

2015

Quelle

Wiley Online Library

Beschreibungen/Notizen

• Sintering mechanisms and kinetics were investigated for ZrB2 ceramics produced using reaction hot pressing. Specimens were sintered at temperatures ranging from 1800°C to 2100°C for times up to 120 min. ZrB2 was the primary phase, although trace amounts of ZrO2 and C were also detected. Below 2000°C, the densification mechanism was grain‐boundary diffusion with an activation energy of 241 ± 41 kJ/mol. At higher temperatures, the densification mechanism was lattice diffusion with an activation energy of 695 ± 62 kJ/mol. Grain growth exponents were determined to be ~4.5, which indicated that a grain pinning mechanism was active in both temperature regimes. The diffusion coefficients for grain growth were 1.5 × 10−16 cm4/s at 1900°C and 2.1 × 10−15 cm4/s at 2100°C. This study revealed that dense ZrB2 ceramics can be produced by reactive hot pressing in shorter times and at lower temperatures than conventional hot pressing of commercial powders.