Plastic deformation of oxide scales at elevated temperatures

Journal Article · Sat Mar 01 04:00:00 EST 1997 · Journal of Materials Research

DOI:https://doi.org/10.1557/JMR.1997.0104· OSTI ID:534463

Zhang, Y; Gerberich, W W; Shores, D A ^[1]

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1. Corrosion Research Center, Department of Chemical Engineering and Materials Science, University of Minnesota, Minneapolis, Minnesota 55455 (United States)

The atomic force microscope (AFM) has been used to observe and characterize for the first time surface steps and grooves on faces of Cr{sub 2}O{sub 3} grains formed as an oxide scale on Ni-30Cr and Ni-30Cr-0.5Y alloys during high temperature oxidation. The very high spatial resolution of the AFM is required to characterize these features. We propose that these surface features, whose dimensions are in the range of nanometers and tens of nanometers, may be interpreted as evidence of highly localized plastic deformation of the oxide scale. The size and spacing of the steps and grooves are consistent with models of plastic deformation based on slip bands derived from dislocation climb or dislocation glide. Mechanical twinning and the models for stress-driven surface instability are also possibly responsible for some surface features. The addition of yttrium to the alloy seemed to enable enhanced plastic deformation of the scale. The strain corresponding to the observed features, estimated by simple models, could relax a significant part of oxide growth and thermal stresses. {copyright} {ital 1997 Materials Research Society.}

• DOE Contract Number: FG02-88ER45337
• OSTI ID: 534463
• Journal Information: Journal of Materials Research, Journal Name: Journal of Materials Research Journal Issue: 3 Vol. 12; ISSN JMREEE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CHROMIUM BASE ALLOYS
CHROMIUM OXIDES
CORROSION PROTECTION
DISLOCATIONS
MORPHOLOGY
NICKEL ALLOYS
OXIDATION
PLASTICITY
PROTECTIVE COATINGS
STRAINS
THERMAL CYCLING
THERMAL STRESSES
TWINNING
YTTRIUM ALLOYS