Oxidation of hafnium carbide in the temperature range 1,400 [degree]C to 2,060[degree]C

Journal Article · Thu Apr 01 04:00:00 EST 1993 · Journal of the American Ceramic Society; (United States)

DOI:https://doi.org/10.1111/j.1151-2916.1993.tb05332.x· OSTI ID:5993047

Bargeron, C B; Benson, R C; Jette, A N; Phillips, T E ^[1]

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1. John Hopkins Univ., Laurel, MD (United States). Applied Physics Lab.

After hafnium carbide has been oxidized at temperatures in the range of 1,400 to 2,060 C, three distinct layers are present in the film cross section: (a) a residual carbide layer with dissolved oxygen in the lattice, (b) a dense-appearing oxide interlayer containing carbon, and (c) a porous outer layer of hafnium oxide. Experimental measurements of layer thicknesses and oxygen concentrations are combined with an extended formulation of moving-boundary diffusion theory to obtain the diffusion constants of oxygen in each of the three layers. The results indicate that the oxide interlayer is a better diffusion barrier for oxygen than either of the other layers. Based on X-ray microanalysis, X-ray diffraction, and resistance measurements, the interlayer is an oxygen-deficient oxide of hafnium with a carbon impurity. The interlayer hardness equals that of the residual carbide layer.

• OSTI ID: 5993047
• Journal Information: Journal of the American Ceramic Society; (United States), Journal Name: Journal of the American Ceramic Society; (United States) Vol. 76:4; ISSN 0002-7820; ISSN JACTAW
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360205* -- Ceramics
Cermets
& Refractories-- Corrosion & Erosion
CARBIDES
CARBON
CARBON COMPOUNDS
CHALCOGENIDES
CHEMICAL COATING
CHEMICAL REACTIONS
CHEMICAL VAPOR DEPOSITION
COHERENT SCATTERING
CRYSTAL DEFECTS
CRYSTAL STRUCTURE
DEPOSITION
DIFFRACTION
DIFFUSION
ELECTRIC CONDUCTIVITY
ELECTRICAL PROPERTIES
ELEMENTS
FILMS
HAFNIUM CARBIDES
HAFNIUM COMPOUNDS
HAFNIUM OXIDES
HARDNESS
IMPURITIES
MECHANICAL PROPERTIES
MICROANALYSIS
NONMETALS
OXIDATION
OXIDES
OXYGEN
OXYGEN COMPOUNDS
PHYSICAL PROPERTIES
REFRACTORY METAL COMPOUNDS
SCATTERING
SURFACE COATING
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
THIN FILMS
TRANSITION ELEMENT COMPOUNDS
X-RAY DIFFRACTION