Advanced Ceramic Fibers for RF Aperture Composites
Abstract
Advanced all-ceramic fiber-based composite materials are needed for structural applications such as hypersonic vehicle thermal protection systems (TPS), armor, directed energy applications, and satellite communications. The mechanical performance of current ceramic matrix composites (CMCs) is limited due to the fiber materials (quartz, Nextel aluminosilicate) and the fiber/matrix interfaces. To address this issue, this project will investigate novel fibers with desired mechanical and thermal properties that can be incorporated into a variety of ceramic matrix materials. Basic research will be conducted focused on the fundamental fiber materials technology, with success enabling a wide range of future concepts at the component and system level.Advanced ceramic fibers are at the core of the next generation of high performance ceramic composites. However, such fibers are not commercially available and, in the case of Boron Nitride, even the precursor chemicals (i.e. polyborazine) may notbe available for purchase. Therefore, R&D efforts such as those proposed here are needed, starting at the basic research level, to generate a fundamental understanding of the materials as they are developed from the ground up. This work focuses on hexagonal Boron Nitride (h-BN) as the fiber of choice due to its unique properties of low dielectric constant, low loss, and high temperature stability.We believe high quality, dense h-BN fibers can be produced through careful chemical synthesis of precursors (e.g. polyborazine), electrospinning of precursors into ordered systems, andheat treatment in Ammonia (NH3), Oxygen, and Nitrogen atmospheres. In addition, other novel methods of producing fibers will be explored such as electrospinning of B2O3/polymer composites and subsequent heat treatment. After novel fibers are produced, they will be integrated into ceramic matrix materials and interactions between fibers and matrix understood; high quality interfaces are critical to realizing high strength and thermal shock resistance. The ultimate goal of this effort is to demonstrate that advanced fibers can be fabricated and provide advanced performance in composite constructs compared to standard COTS materials. This advanced performance will be demonstrated by a combination of thermal, high temperature mechanical, and high temperature RF testing of the composite materials.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jun 09, 2021
- Source ID
- N000142112526
Entities
People
- Keith Caruso
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy