A study of the growth of [alpha]-Al[sub 2]O[sub 3] scales using high-resolution imaging secondary ion mass spectrometry

Journal Article · Sat Jan 01 04:00:00 EST 1994 · Corrosion (Houston); (United States)

DOI:https://doi.org/10.5006/1.3293495· OSTI ID:5439418

Prescott, R; Mitchell, D F ^[1]; Graham, M J ^[2]

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1. Sherritt Gordon, Ltd., Fort Sasketchewan, Alberta (Canada). Sherritt Technologies
2. Inst. for Microstructural Sciences, Ottawa, Ontario (Canada). National Research Council

The oxide morphology and transport processes occurring during the growth of [alpha]-aluminum oxide ([alpha]-Al[sub 2]O[sub 3]) at 1,200 C on an iron-aluminum (Fe-25 wt% Al) alloy and a nickel-aluminum (Ni-32 wt% Al) alloy ([beta]-NiAl) were investigated. Imaging secondary ion mass spectrometry (SIMS) was used to locate the different isotopic species following two-stage oxidations in [sup 16]O[sub 2] and [sup 18]O[sub 2]. These images (with 0.1 [mu]m lateral resolution) showed the growth of ridges of [alpha]-Al[sub 2]O[sub 3] occurred by outward transport of Al for NiAl. As the ridges grew taller and wider, inward diffusion of oxygen played a role in the growth process. Mature alumina scales thickened by outward transport of Al and inward diffusion of oxygen. [alpha]-Al[sub 2]O[sub 3] formed on Fe-25 wt% Al also grew through a combination of Al and oxygen diffusion, the latter appearing to take place along grain boundaries in the coarse-grained oxide.

• OSTI ID: 5439418
• Journal Information: Corrosion (Houston); (United States), Journal Name: Corrosion (Houston); (United States) Vol. 50:1; ISSN 0010-9312; ISSN CORRAK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360105* -- Metals & Alloys-- Corrosion & Erosion
ALLOYS
ALUMINIUM ALLOYS
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CORROSION
CRYSTAL GROWTH
IRON ALLOYS
IRON BASE ALLOYS
KINETICS
MASS TRANSFER
NICKEL ALLOYS
NICKEL BASE ALLOYS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS