"BORON NITRIDE-NANOTUBE–SILICON NITRIDE COMPOSITES FOR HIGH TEMPERATURE RADOME APPLICATIONS" 

Vincent Mika, MSE PhD Candidate 

Advisor(s): Prof. Rodney Trice, Prof. Michael Titus

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ABSTRACT

High temperature radomes necessitate a number of design constraints, including a need for stability at high temperatures while maintaining a low dielectric constant to minimize signal loss. The addition of boron nitride nanotubes to a conventional silicon nitride system represents a potential to lower dielectric constant while not sacrificing other material properties. This study investigates the manufacturing processes needed as well as the mechanical properties of zero to 3 volume percent boron nitride nanotube loaded silicon nitride, with both standard puritiy and high purity nanotubes being studied. 4-point bend testing was performed, as well as impulse excitation testing and fracture surface micrography. An investigation of BNNT dispersion within the part was conducted, showing strong dispersion. The results suggest the combined system shows promise in the field of radome materials, but may require further study.