Effects of Temperature Gradients and Heat Fluxes on High-Temperature Oxidation

Abstract

The effects of a temperature gradient and heat flux on point defect diffusion in protective oxide scales were examined. Irreversible thermodynamics were used to expand Fick's first law of diffusion to include a heat flux term-a Soret effect. Oxidation kinetics were developed for the oxidation of cobalt and of nickel doped with chromium. Research is described to verify the effects of a heat flux by oxidizing pure cobalt in a temperature gradient at 900ºC, and comparing the kinetics to isothermal oxidation. No evidence of a heat flux effect was found.