Ceramic Springs

Hypersonic aircraft, especially reusable hypersonic aircraft, require advancements in high temperature materials because of the extreme temperatures resulting from frictional heating. One aspect of this problem is making seals that can function through a very large temperature range, perhaps up to 1000 deg;C or higher. Metallic springs essentially lose their ability to function at 600 deg;C or below. Silicon nitride compression springs have previously been evaluated by NASA and have been found to be capable of functioning throughout that temperature range, but lack the strength required for most applications. They undergo very limited deformation before failure. TDA will improve the feedstocks and modify the existing process for manufacturing ceramic springs. Through improvements to the grain structure, the resulting springs will overcome their previous limitations.