Accession Number:

ADA446193

Title:

Creep-Rupture Behavior of a Woven Ceramic Matrix Composite at Elevated Temperatures in a Humid Environment

Descriptive Note:

Master's thesis

Corporate Author:

AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH DEPT OF AERONAUTICS AND ASTRONAUTICS

Personal Author(s):

Report Date:

2006-03-01

Pagination or Media Count:

118.0

Abstract:

This study focused on moisture and temperature effects on the embrittlement and stress-rupture life of the SiCSiC CMC Syl-iBNBNSiC. The Syl-iBNBNSiC is composed of Sylramic fibers with an in-situ layer of boron nitride Syl-iBN, boron nitride interphase BN, and SiC matrix. Stress rupture tests and monotonic tests were performed on the specimens. Tests were conducted under 100 humidity and laboratory air environments at three temperatures, 450 C, 750 C, and 950 C. These temperatures were chosen because they fall below the intermediate range, within the range, and above the range, respectively. This study found that while this CMC does experience embrittlement at intermediate temperatures, it also occurs at temperatures above the intermediate range. Scanning Electron Microscopy SEM analysis showed the embrittlement and pesting in the specimens increased with time, temperature, and moisture exposure, leading to premature failure. An analysis of the data confirmed that with increase in temperature and exposure to moisture, the stress-rupture life of the Syl-iBNBNSiC was considerably shortened

Subject Categories:

  • Ceramics, Refractories and Glass
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE