Densification and Fracture Responses of (Ta1−xWx)C–WC Composites
Abstract
The mechanical behavior of 90 vol% (Ta1−xWx)C–10 vol% WC (x ≈ 0.2) [90(Ta0.8W0.2)C–10WC] composites is described, achieving a significant enhancement in mean fracture strength compared with nominally pure TaC prepared under identical processing conditions (from 114 to 362 MPa), and a higher characteristic strength (from 188 to 377 MPa), while maintaining the same Weibull modulus of 13. The fracture strengths correspond to calculated critical flaw sizes in the range of 5–10 μm and are consistent with the microstructure observations presented. The 90(Ta0.8W0.2)C–10WC composite begins densification at an onset sintering temperature of 1503 K, which is 500 K lower than TaC. It also exhibits enhanced densification by inhibiting grain growth at sintering temperatures up to 2173 K, therefore resulting in a relative density of 98% compared with 80% for TaC. These results show a promising guideline from which ceramic additions can be chosen to enhance the densification and functionality of ultrahigh‐temperature ceramics.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Jun 16, 2022
- Source ID
- 10.1002/adem.202200026
Entities
People
- Ekaterina Novitskaya
- James P. Kelly
- Olivia A Graeve
- Ved S. Vakharia
Organizations
- Air Force Office of Scientific Research
- Alfred University
- University of California, San Diego