High-temperature oxidation behavior of a Ni-Cr-Al-Fe-Y alloy. [Ni-16Cr-4. 5Al-4Fe-0. 01Y-0. 04C]

Journal Article · Wed Apr 01 04:00:00 EST 1992 · Oxidation of Metals; (United States)

DOI:https://doi.org/10.1007/BF00665187· OSTI ID:7068786

Tawancy, H M; Sridhar, N ^[1]

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1. King Fahd Univ. of Petroleum and Minerals, Dhahran (Saudi Arabia)

A study was conducted to examine the isothermal oxidation behavior of a wrought Ni-Cr-Al-Fe-Y alloy in air at temperatures in the range of 950-1,150 C. Oxidation kinetics were determined from weight-change measurements. Analytical electron microscopy, scanning electron microscopy, and X-ray diffraction were used to characterize the morphology, structure, and composition of the oxide scale. Overall oxidation of the alloy was found to follow parabolic kinetics. Under steady-state conditions, the oxidation reaction appeared to be controlled by diffusional transport in an adherent Y-modified a-Al{sub 2}O{sub 3} scale with an activation energy of about 400KJ/mol. Yttrium was found to preferentially segregate to grain boundaries of a-Al{sub 2}O{sub 3} which maintained a fine columnar grain structure about 0.05-0.2 {mu}m in size. Based upon the results obtained, it was suggested that the role of Y was to promote the formation of a thin layer of a-Al{sub 2}O{sub 3} with improved mechanical strength.

• OSTI ID: 7068786
• Journal Information: Oxidation of Metals; (United States), Journal Name: Oxidation of Metals; (United States) Vol. 37:3-4; ISSN 0030-770X; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ACTIVATION ENERGY
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CARBON ADDITIONS
CHALCOGENIDES
CHEMICAL COMPOSITION
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHROMIUM ALLOYS
COBALT ALLOYS
COBALT BASE ALLOYS
COHERENT SCATTERING
CRYSTAL STRUCTURE
DATA
DIFFRACTION
DIFFUSION
ELECTRON MICROSCOPY
ELEMENTS
ENERGY
EXPERIMENTAL DATA
GRAIN BOUNDARIES
GRAIN SIZE
HAYNES ALLOYS
HEAT TREATMENTS
INFORMATION
IRON ALLOYS
KINETICS
MASS TRANSFER
METALLURGICAL EFFECTS
METALS
MICROSCOPY
MICROSTRUCTURE
MORPHOLOGY
NICKEL ALLOYS
NICKEL BASE ALLOYS
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SCANNING ELECTRON MICROSCOPY
SCATTERING
SIZE
SPECTROSCOPY
SULFUR ADDITIONS
TEMPERATURE RANGE
TEMPERATURE RANGE 1000-4000 K
TRANSITION ELEMENTS
TRANSMISSION ELECTRON MICROSCOPY
WEIGHT
X-RAY DIFFRACTION
X-RAY SPECTROSCOPY
YTTRIUM
YTTRIUM ADDITIONS
YTTRIUM ALLOYS