Theoretical analysis of the deflection test used in single-surface oxidation of metallic samples

Abstract

On the basis of the experimental results on deflection obtained by Delaunay during single-surface oxidation of metallic samples, a theoretical analysis of this deflection test was carried out. Two important problems were established concerning the physical signification of the oxide stress calculated from the measured deflection and the relation between the oxide adherence and the oxide stress. In particular, it appears that the oxide stress level determined by the deflection test is only representative of the stresses relieved by the sample curvature. Secondly, spalling of the oxide layer is directly related to the product of the residual stress value by the curvature of the sample. Some experimental results, recently obtained, confirm this theoretical analysis.