Fiscal Year:
1983
Title:
COMPOSITES
Agency:
NASA
Contract:
N/A
Award Amount:
$48,000.00
Abstract:
CARBON-CARBON COMPOSITES ARE IMPORTANT HIGH TEMPERATURE STRUCTURAL MATERIALS. BROADENING THE USE OF CARBON-CARBON MATERIALS IN OXIDIZING ENVIRONMENTS REQUIRES THE DEVELOPMENTOF THIN CRACK-FREE OXIDATION-RESISTANT COATINGS FOR HIGH- STRENGTH COMPOSITE SUBSTRATES. THE PRIMARY OBJECTIVE OF THISPROGRAM IS TO DETERMINE THE FEASIBILITY OF FORMING PROTECTIVE SIC AND SI(3)N(4) COATINGS BY CHEMICAL VAPOR DEPOSITION (CVD) ON HIGH-STRENGTH CARBON-CARBON COMPOSITES TAKING ADVANTAGE OF THE THERMAL INSTABILITY OF COMPOSITES PROCESSED AT LOW TEMPERATURES. THIS WORK IS CONDUCTED BY CVD COATING 3D CARBON-CARBON SUBSTRATES DENSIFIED AT LOW TEMPERATURES AND MADE FROM UNSTABLE HIGH-STRENGTH CARBON FIBERS. AFTER COATING, THE TEMPERATURE IS RAISED SO THAT SUBSTRATE CONCTRACTS RELATIVE TO THE COATING. THIS CIRCUMVENTS A SIGNIFICANT PORTION OF THE MISMATCHED IN THE COEFFICIENT OF THERMAL EXPANSION BETWEEN THE SUBSTRATE AND COATING AND PROVIDES CRACK-FREE COATINGS. BOTH SIC AND SI(3)N(4) COATINGS ARE INCLUDED IN THIS PROJECT BECAUSE THEY DIFFER IN COEFFICIENT OF THERMAL EXPANSION AND ELASTIC MODULUS. COATED SPECIMENS ARE EVALUATED IN STATIC AIR OXIDATION TESTS. SUCCESSFUL DEMONSTRATION OF THE ABOVE CONCEPT IN PHASE I LEADS TO THE DEVELOPMENT OF THIN COATINGSWHICH DON NOT RELY ON GLASS SEALING FRO PROTECTION OF THE SUBSTRATE. SUCH COATINGS ARE REQUIRED FOR COMPONENTS OPERATING UNDER DYNAMIC CONDITIONS AND APPLICATIONS REQUIRING VERY HIGH TEMPERATURE PERFORMANCE.
Principal Investigator:
James e. sheehan
PRINCIPAL INVESTIGATOR
Business Contact:
Small Business Information at Submission:
Fiber Materials Inc
Biddeford Industrial Park Biddeford, ME 04005
EIN/Tax ID:
DUNS:
N/A
Number of Employees:
N/A
Woman-Owned:
No
Minority-Owned:
No
HUBZone-Owned:
No