Accession Number:

ADA476055

Title:

Nanomodified Carbon/Carbon Composites for Intermediate Temperature

Descriptive Note:

Final rept. 14 Feb 2005-31 Aug 2007

Corporate Author:

KOO AND ASSOCIATES INTERNATIONAL INC AUSTIN TX

Report Date:

2007-08-31

Pagination or Media Count:

53.0

Abstract:

An improved CarbonCarbon Composite CCC with enhanced thermo-oxidative resistant performance at intermediate temperatures 371 to 650 C is being developed. A nanophase is introduced into the CCC prior to cure for improved and maintained mechanical strength by preventing oxidation of the CCC. Four material systems based on Lonza PT-15 cyanate ester CE resin and selected nanoparticles were chosen to produce prepregs. They were fabricated into composites for carbonization and densification to produce nanomodified CCC using CVI process. Two sets of 30.48 by 30.48 by 0.38 cm NCCC panels were fabricated. Ten material systems based on synthetic AR mesophase pitch and silicon carbide nanoparticles in two groups were also selected to produce CCC using the SMJ patented in-situ polymerization method. Two sets of 15.25 by 15.25 by 0.32 cm CCC panels were fabricated for these two groups. A CC and a CSiC type composites fabricated by DACC of Korea were included for comparison. Microstructure analyses of pre- and post-test CCC specimens using SEM and optical microscopy provided more fundamental understanding of material behavior. The nanomodified CE CCC PT1530B, PT15Im and PT15P0SS are more thermo-oxidative resistant than the baseline CCC PT15. With TGA for heat soaking in air environment, the DACC CSiC composite exhibited the best performance and the AR mesophase pitchSiC impregnated with Ceraset trademark exhibited the most thermo-oxidative resistant NCCC. It was followed by the AR mesophase pitchSiC NCCC. The nanomodified PT-15 CE NCCC is the most unfavorable of the three NCCC groups. The density of the NCCC and the percentage loading of SiC nanoparticles appear to be the most important factors determining the thermo-oxidative properties of NCCC within the same group.

Subject Categories:

  • Laminates and Composite Materials
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE