Stress Generation in Tantalum During Oxidation

Abstract

Thin rectangular specimens of tantalum were oxidized on one side at 500°C and 1 atm oxygen pressure. From curvature measurements, the bending stresses arising as a consequence of the oxidation process were determined and correlated with known oxidation rate behavior and oxide morphology. The simplest stress model, that of a uniform film on a substrate, was shown to be an inadequate description of the stress source, thus reflecting the complexity of the tantalum‐oxygen reaction. A model relating the stress gradient to the oxygen concentration gradient was tested and shown to be reasonably consistent with the experimental data.