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A thermal oxide scale has been grown on a high-chromium iron-nickel alloy under very low oxygen partial pressure (1050 °C, 10 −10 Pa). In this paper, a special attention has been paid to morphological and chemical characterizations of the scale by scanning transmission electron microscopy and energy dispersive X-ray analysis at high resolution on a cross-section thin lamella beforehand prepared by using a combined focused ion beam/scanning electron microscope instrument. The complexity of the oxide layer is highlighted, and the correlation between the present results and the ones of a photoelectrochemical study is discussed. [ABSTRACT FROM AUTHOR]

The present work is focused on the oxidation at 1050 °C of a model chromia-forming alloy, paying special attention to the control of the oxygen partial pressure. Taking benefit of a recently developed approach to describe and fit photocurrent energy spectra, photoelectrochemical characterizations allowed to reveal the presence, in the scale formed at low P(O2) (10-15 atm), of an unexpected high number of oxide phases. This result underlines the complexity of the scale in term of chemical composition as well as of the semiconducting types of the individual phases. [ABSTRACT FROM AUTHOR]

Abstract: Important compressive stress developed in TiO2 films thermally grown on pure titanium in oxygen is known to induce scale decohesion at the metal–oxide interface. If such a phenomenon is identified in the literature to play a key role on life time of many materials used at high temperatures, no data at the microscopic level can be found at this time. In the present work using photoelectrochemical microscopy, new information in the form of two specific images ICI (interface cohesion image) and SQI (structural quality image) could be obtained. Such images revealed the level of scale decohesion induced by growth stress as well as the structural quality of the oxide layer. [Copyright &y& Elsevier]