THE MECHANICAL FAILURE OF OXIDE SCALES UNDER TENSILE OR COMPRESSIVE LOAD

Simple mechanical models which could be used to calculate the stresses in an oxide scale on a flat metal substrate are presented. The sources for these stresses and the experimental techniques for measuring stresses and oxide failure are also briefly summarized. The options for stress relief in oxide scales are listed. The importance of lateral oxide growth and oxide plasticity is emphasized. Both processes result in stress relief without scale failure. This is followed by a detailed survey of the proposed mechanisms and models for oxide scale failure under tensile or compressive forces. Experimental evidence in support of these mechanisms is examined and the critical factors for predicting oxide failure are given.