ISSN:
1573-4803
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract Electron microscopy has been used to characterize the stress effects which occur during the oxidation of iron in the temperature range 400–700° C. Spalling and de-cohesion of the outer hematite (α-Fe2O3) layer is often observed, and analysis of the resulting scrolled oxide indicates a strong compressive stress gradient. In contrast, tensile cracks are frequently seen in the magnetite (Fe3O4) layer, while the underlying wustite (Fe1−xO) and the iron substrate are apparently able to accommodate the stresses to some extent by plastic deformation. The Pilling-Bedworth model can adequately be applied at the α-Fe2O3-Fe3O4 interface since anion diffusion occurs in the hematite. However, since cation diffusion is dominant in the other oxides, it is suggested that the anion volume ratio can be applied to the Fe3O4-Fe1−xO interface where the anion sublattice remains unchanged, in order to predict the stress state.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00540812
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