Emittance, catalysis, and dynamic oxidation of Ti-14Al-21Nb

Conference · Sun Jan 01 00:00:00 EST 1989

OSTI ID:5045000

Wiedemann, K E; Clark, R K; Sankaran, S N

Emittance, catalytic efficiency, and dynamic oxidation resistance were determined for Ti-14Al-21Nb exposed to simulated hypersonic flight conditions at a surface temperature of 982 C for up to 8 hr. The emittance was low before testing (about 0.3), but high after testing (0.85 to 0.89). Catalytic efficiencies were high which means that during exposure to hypersonic conditions Ti-14Al-21Nb will experience a large amount of heating due to recombination of gaseous atoms at the surface. Oxides formed on the surface spalled readily, beginning with the first exposure cycle. Oxygen diffusion into the base metal was observed. The solubility limit of oxygen in the base metal was estimated to be 12.5 at.%, and the diffusion coefficient for oxygen in the base metal was 0.0234 (sq cm/sec) exp (-45090 (cal/mole. deg K)/RT) between 704 C and 982 C. The oxide was composed of several layers of different color but similar composition: TiO2, Al2O3, TiN, and Ti3O5 were identified by x-ray diffraction.

• Research Organization: National Aeronautics and Space Administration, Hampton, VA (USA). Langley Research Center
• OSTI ID: 5045000
• Report Number(s): N-90-10248; NASA-TP-2955; L-16606; NAS-1.60:2955; CONF-880126-
• Resource Relation: Conference: TMS-AIME/ASM symposium on high temperature mechanical properties of ordered intermetallics, Phoenix, AZ (USA), 25-29 Jan 1988
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
CATALYSIS
EMISSIVITY
OXIDATION
NIOBIUM ALLOYS
TITANIUM BASE ALLOYS
EXPERIMENTAL DATA
HYPERSONIC FLOW
TEMPERATURE EFFECTS
ALLOYS
CHEMICAL REACTIONS
DATA
FLUID FLOW
INFORMATION
NUMERICAL DATA
OPTICAL PROPERTIES
PHYSICAL PROPERTIES
SURFACE PROPERTIES
TITANIUM ALLOYS
360104* - Metals & Alloys- Physical Properties