NDE for Characterizing Oxidation Damage in Reinforced Carbon-CarbonIn this study, coated reinforced carbon-carbon (RCC) samples of similar structure and composition as that from the NASA space shuttle orbiter s thermal protection system were fabricated with slots in their coating simulating craze cracks. These specimens were used to study oxidation damage detection and characterization using NDE methods. These specimens were heat treated in air at 1143 and 1200 C to create cavities in the carbon substrate underneath the coating as oxygen reacted with the carbon and resulted in its consumption. The cavities varied in diameter from approximately 1 to 3 mm. Single-sided NDE methods were used since they might be practical for on-wing inspection, while x-ray micro-computed tomography (CT) was used to measure cavity sizes in order to validate oxidation models under development for carbon-carbon materials. An RCC sample having a naturally-cracked coating and subsequent oxidation damage was also studied with x-ray micro-CT. This effort is a follow-on study to one that characterized NDE methods for assessing oxidation damage in an RCC sample with drilled holes in the coating. The results of that study are briefly reviewed in this article as well. Additionally, a short discussion on the future role of simulation to aid in these studies is provided.
Document ID
20090022154
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Roth, Don J. (NASA Glenn Research Center Cleveland, OH, United States)
Rauser, Richard W. (Toledo Univ. Toledo, OH, United States)
Jacobson, nathan S. (NASA Glenn Research Center Cleveland, OH, United States)
Wincheski, Russell A. (NASA Langley Research Center Hampton, VA, United States)
Walker, James L. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Cosgriff, Laura A. (Cleveland State Univ. Cleveland, OH, United States)