Project Title:

Improved CVD Silicon Carbide Fibers

04.01-2681
Improved CVD Silicon Carbide Fibers
Advanced Technology Materials, Inc.
520-B Danbury Road
New Milford
CT
06776
Ward C.
Stevens
(203-355-2681)
LeRC

Abstract:

Engines of high thrust-to-weight ratio and hypersonic vehicles require high-temperature
structural materials which depend on the availability of suitable fiber reinforcements.
Commercially available silicon carbide fibers formed by chemical vapor deposition
(CVD) suffer from poor creep resistance, a result of free silicon found at the grain
boundaries. This problem, a direct result of the fiber fabrication process, limits
their use to temperatures less than 1000 C. A unique source reagent for CVD has been
developed for the electronics community which enables the reproducible growth of
stoichiometric, single-crystal, silicon carbide for high power electronic devices.
This reagent should enable the fabrication of a silicon-free, silicon carbide fiber,
which should be creep resistant to 1550 C.
Phase I will determine the physical properties and the high-temperature mechanical
properties of monofilament silicon carbide made by CVD using this innovative, "molecular-source"
reagent. Phase II will more fully develop the properties of the fiber and develop
a manufacturing process for its production.

Potential Commercial Application:

Potential Commercial Applications:  The applications would be in hot sections of
high-temperature turbofan and turbojet engines and structures on hypersonic vehicles.