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 00:00:00 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), Vol. 50:1; ISSN 0010-9312
• Country of Publication: United States
• Language: English

Related Subjects

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