Oxidation behavior of FeAl+Hf, Zr, B

Journal Article · Mon Oct 01 04:00:00 EDT 1990 · Oxidation of Metals; (USA)

DOI:https://doi.org/10.1007/BF00665018· OSTI ID:6118609

Smialek, J L; Gaydosh, D J ^[1]; Doychak, J ^[2]

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1. National Aeronautics and Space Administration, Cleveland, OH (USA)
2. Sverdrup Technology, Inc., Cleveland, OH (USA)

The oxidation behavior of Fe-40Al-1Hf, Fe-40Al-1Hf-0.4B, and Fe-40Al-0.1Zr-0.4B (at.%) alloys was characterized after 900, 1,000, and 1,100C exposures. Isothermal tests revealed parabolic kinetics after a period of transitional {theta}-alumina scale growth. The parabolic growth rates for the subsequent {alpha}-alumina scales were about five times higher than those for NiAl+0.1Zr alloys. The isothermally grown scales showed a propensity toward massive scale spallation due to both extensive rumpling from growth stresses and to an inner layer of HfO{sub 2}. Cyclic oxidation for 200 1-hr cycles produced little degradation at 900 or 1,000C, but caused significant spallation at 1,100C in the form of small segments of the outer scale. The major difference in the cyclic oxidation of the three FeAl alloys was increased initial spallation for FeAl+Zr, B. Although these FeAl alloys showed many similarities to NiAl alloys, they were generally less oxidation-resistant. It is believed that this resulted from nonoptimal levels of dopants and larger thermal-expansion mismatch stresses.

• OSTI ID: 6118609
• Journal Information: Oxidation of Metals; (USA), Journal Name: Oxidation of Metals; (USA) Vol. 34:3-4; ISSN 0030-770X; ISSN OXMEA
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
BORON ADDITIONS
BORON ALLOYS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
DATA
ELECTRON MICROSCOPY
EXPERIMENTAL DATA
HAFNIUM ADDITIONS
HAFNIUM ALLOYS
INFORMATION
INTERMETALLIC COMPOUNDS
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
MEASURING METHODS
MICROSCOPY
NUMERICAL DATA
OXIDATION
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SCANNING ELECTRON MICROSCOPY
VERY HIGH TEMPERATURE
ZIRCONIUM ADDITIONS
ZIRCONIUM ALLOYS