Oxidation induced stresses and some effects on the behavior of oxide films

Abstract

The elastic and viscoelastic stresses created during the oxidation of curved surfaces are calculated. The stress state and amplitude are shown to depend sensitively upon the oxidation site (interface or surface) and the oxidation strain (uniaxial or dilational). The viscoelastic stresses depend, in addition, on the rate of oxidation, vis-a-vis the viscosity of the oxide. In most cases, the stresses increase rapidly as the radius of curvature of the surface decreases. The influence of the stresses on several important oxidation phenomena are discussed. Specifically, corner effects on the oxidation rate, cracking and spalling of the oxide, and plastic deformation of the substrates are briefly addressed.