Wrinkling of {alpha}-alumina films grown by thermal oxidation. 1: Quantitative studies on single crystals of Fe-Cr-Al alloy

Journal Article · Tue Sep 01 04:00:00 EDT 1998 · Acta Materialia

DOI:https://doi.org/10.1016/S1359-6454(98)00133-5· OSTI ID:669805

Tolpygo, V K; Clarke, D R ^[1]

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1. Univ. of California, Santa Barbara, CA (United States)

Quantitative measurements of the wrinkling morphology of the alpha-alumina scales formed by thermal oxidation at 1000 C and its evolution with oxidation time have been made using atomic force microscopy. The wrinkling wavelength and amplitude, and from these the surface area of the scale, for (110), (100) and (111) oriented single crystals of Fe-Cr-Al alloy as a function of oxidation time are presented. The residual stress in the scales is determined using piezospectroscopy. Together these results provide the basis for determining the lateral strains associated with the growth of the oxide. Crystallographic orientation of the alloy surface has a pronounced effect on both the wrinkling morphology and stress in the scale during the first 20--30 h of oxidation. The presence of the reactive element, yttrium, suppresses wrinkling and restricts lateral growth but it does not decrease the stress in the oxide.

• OSTI ID: 669805
• Journal Information: Acta Materialia, Journal Name: Acta Materialia Journal Issue: 14 Vol. 46; ISSN 1359-6454; ISSN ACMAFD
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
ALUMINIUM OXIDES
CHROMIUM ALLOYS
IRON ALLOYS
MICROSCOPY
MORPHOLOGY
OXIDATION
RESIDUAL STRESSES
SCALING