Effect of Pyrolysis Temperature and Dopant on the Frequency-Dependent and Temperature-Dependent Electromagnetic Properties for Ultra-High Temperature Ceramics (UHTCs) Reinforced Ceramic Composites
Abstract
This proposal is to study the effect of pyrolysis temperature and dopant on the frequency-dependent and temperature-dependent permittivity for ultra-high temperature ceramics (UHTCs) reinforced ceramic composites, and to investigate the corresponding electromagnetic (EM) wave absorption at a broad application temperature range (e.g., from room temperature to ~1600C) with the frequency range at the X to Ka band (8-40 GHz). In this proposed fundamental research work, we will focus on the absorption induced by electrical conduction loss from the free carriers and polarization loss. Both the free carriers’ concentration and mobility, as well as the moment of dipoles, are temperature-dependent and frequency dependent. The understanding of the mechanism for ultra-high temperature ceramics (UHTC) reinforced ceramic composites is the focus of this study. Based on the knowledge obtained, an optimized material selection and composition can be effectively decided to achieve desired electromagnetic absorption property at the desired temperature and frequency settings. The relationship between processing, microstructure, properties, and performance of materials will be systematically studied and documented. The understanding of the mechanism will be used as a guideline to design an effective electromagnetic absorption ceramic composites with a minimum thickness sustainable at a broad temperature range to be used for the harsh environment applications, e.g., airplane nozzle, wingtip, nose cone, etc.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2023
- Source ID
- FA95502110057
Entities
People
- Cheryl Xu
Organizations
- Air Force Office of Scientific Research
- North Carolina State University
- United States Air Force