Oxidation of {gamma}{prime}-Ni{sub 3}Al and {gamma}{prime}-Ni{sub 3}Al(Si) intermetallic compounds at low-oxygen pressures

Journal Article · Mon Apr 01 04:00:00 EST 1996 · Oxidation of Metals

DOI:https://doi.org/10.1007/BF01046986· OSTI ID:245142

Yi, H C ^[1]; Smeltzer, W W; Petric, A ^[2]

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1. Guigne International, Newfoundland (Canada)
2. McMaster Univ., Hamilton, Ontario (Canada)

The oxidation behavior of {gamma}{prime}-Ni{sub 3}Al and {gamma}{prime}-Ni{sub 3}Al(Si) (Ni{sub 75}Al{sub 20}Si{sub 5}) intermetallic compounds was studied at 1073 K and oxygen partial pressures of 5 {approximately} 9 x 10{sup {minus}6} atm, 1.2 x 10{sup {minus}14} atm, and 1.2 x 10{sup {minus}19} atm by means of a manometric apparatus, and Rhines packs of NiO/Ni and FeO/Fe, respectively. Oxidation kinetics were determined either by recording weight gains or by measuring the internal-oxidation-zone depths. The structures and morphologies of oxides were also studied. Relatively low oxidation rates occurred for both compounds when oxidized in the manometric apparatus, while fast internal oxidation was observed for both compounds in the NiO/Ni pack. The fastest oxidation occurred in the {gamma}{prime}-Ni{sub 3}Al compound in the FeO/Fe pack. A healing Al{sub 2}O{sub 3} layer was formed on the surface of {gamma}{prime}-Ni{sub 3}Al(Si) compound in the FeO/Fe pack, indicating a synergistic effect between the solute elements in the compound at the oxygen pressures corresponding to the dissociation of FeO. The oxidation rate was found to depend on the volume expansion associated with solute-atom oxidation.

• Sponsoring Organization: USDOE
• OSTI ID: 245142
• Journal Information: Oxidation of Metals, Journal Name: Oxidation of Metals Journal Issue: 3-4 Vol. 45; ISSN OXMEAF; ISSN 0030-770X
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
INTERMETALLIC COMPOUNDS
NICKEL BASE ALLOYS
OXIDATION
SILICON ALLOYS
TEMPERATURE RANGE 1000-4000 K