국내 최대 기계 및 로봇 연구정보

기술보고서

기술보고서 게시판 내용
타이틀	Active Oxidation of a UHTC-Based CMC
저자	Glass, David E.;; Splinter, Scott C.
Keyword	ARC HEATING;; CERAMIC MATRIX COMPOSITES;; CIRCUIT DIAGRAMS;; HYPERSONIC VEHICLES;; OXIDATION;; PYROMETERS;; REFRACTORY MATERIALS;; STAGNATION PRESSURE;; SURFACE TEMPERATURE;; THERMOCOUPLES;; WIND TUNNEL TESTS
URL	http://hdl.handle.net/2060/20120007419
보고서번호	NF1676L-12008
발행년도	2012
출처	NTRS (NASA Technical Report Server)
ABSTRACT	The active oxidation of ceramic matrix composites (CMC) is a severe problem that must be avoided for multi-use hypersonic vehicles. Much work has been performed studying the active oxidation of silicon-based CMCs such as C/SiC and SiC-coated carbon/carbon (C/C). Ultra high temperature ceramics (UTHC) have been proposed as a possible material solution for high-temperature applications on hypersonic vehicles. However, little work has been performed studying the active oxidation of UHTCs. The intent of this paper is to present test data indicating an active oxidation process for a UHTC-based CMC similar to the active oxidation observed with Si-based CMCs. A UHTC-based CMC was tested in the HyMETS arc-jet facility (or plasma wind tunnel, PWT) at NASA Langley Research Center, Hampton, VA. The coupon was tested at a nominal surface temperature of 3000 F 񢃲 C), with a stagnation pressure of 0.026 atm. A sudden and large increase in surface temperature was noticed with negligible increase in the heat flux, indicative of the onset of active oxidation. It is shown that the surface conditions, both temperature and pressure, fall within the region for a passive to active transition (PAT) of the oxidation.