Boron Nitride Nanotube (BNNT) Reinforced Non-Oxide Ceramic Matrix Composites
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Authors
Ansell, Troy Youngmin
Subjects
molten salt synthesis
MSS
ceramic matrix composites
CM
ultra-high temperature ceramics
UHTC
boron nitride nanotubes
BNNT
MSS
ceramic matrix composites
CM
ultra-high temperature ceramics
UHTC
boron nitride nanotubes
BNNT
Advisors
Date of Issue
2023-10-27
Date
Publisher
Monterey, CA; Naval Postgraduate School
Language
Abstract
Ultra-high temperature ceramics (UHTC) are required for a growing number of applications in hypersonic vehicles and inside gas turbine engines. One requirement is fabrication of larger UHTC parts necessitating novel thermal management techniques like heat piping by nanoparticles. Ceramic matrix composites (CMC) with the UHTC silicon nitride (Si3N4) as the matrix material was printed with boron nitride nanotubes (BNNT), either 2 or 4 vol%. Printed CMC with reasonable model fidelity were achieved with pure Si3N4 and 4 vol% BNNT-CMC. The composite with 2 vol% BNNT failed to print fully. Because of the difficulty in printing Si3N4 CMC, these ceramics were also fabricated by the molten salt synthesis (MSS) method. Si3N4 powders were pressed together using both a uniaxial press and a cold isostatic press to push the powders into close contact. Then the powders were covered in salt and heated to 1000 °C for three hours and allowed to cool back down to room temperature. The theoretical density of Si3N4 fabricated in this way was found to be 80% and represents a potential path to fabricate these ceramics at low temperatures as well as fabricate Si3N4-BNNT composites without degradation of the BNNT that would typically occur otherwise.
Type
Report
Description
NPS NRP Executive Summary
Series/Report No
Department
Mechanical and Aerospace Engineering (MAE)
Organization
Naval Research Program (NRP)
Identifiers
NPS Report Number
Sponsors
ASN(RDA) - Research, Development, and Acquisition
Funder
This research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE0605853N/2098). https://nps.edu/nrp
Chief of Naval Operations (CNO)
Chief of Naval Operations (CNO)
Format
4 p.
Citation
Distribution Statement
Approved for public release. Distribution is unlimited.
Rights
This publication is a work of the U.S. Government as defined in Title 17, United States Code, Section 101. Copyright protection is not available for this work in the United States.