NAnocomposite Core-Rim structures for Enhanced tOUghness and Strength at extreme temperatures (NACREOUS)
Abstract
Previous collaborative efforts between the Missouri University of Science and Technology and the Institute of Science and Technology for Ceramics have produced intriguing observations related to a class of hierarchical nanocomposites with average strengths exceeding 600 MPa at 2100°C. These remarkable materials consisted of a nominally pure boride grain core and a rim structure composed of a solid solution of the grain core material with a second transition metal. Further studies revealed that nano-sized precipitates of the second transition metal (or its carbide) could be developed in the rim structure through post-densification annealing treatments, which further enhanced the elevated temperature strength. We believe these are the highest strengths reported for any ceramic material at such extreme temperature. However, knowledge of the mechanisms responsible for the formation of these structures and the incredible strengths at elevated temperatures remain unknown. This project will advance the fundamental knowledge of the formation mechanisms, properties, and performance of hierarchical nanocomposites that form in boride ceramics with the addition of a second transition metal. The project will lead to new knowledge in several areas including diffusion mechanisms responsible for formation of the hierarchical nanocomposite structures, ultra-high temperature structure-property relationships, and the response of these materials to extreme heat fluxes and reactive gas atmospheres. The knowledge generated by these tasks will be applied to design a second generation of hierarchical nanocomposites with improved properties.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 21, 2022
- Source ID
- FA95502110399XX0
Entities
People
- William G. Fahrenholtz
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of Missouri System