Phase-field modeling of scale roughening induced by outward growing oxide

A phase-field modeling of oxide roughening induced by outward growing oxide is proposed, which involves a reaction rate formula derived based on the detailed balance of a chemical system. The Allen–Cahn equation, in cooperation with the reaction-diffusion and mechanical equilibrium equations, are then established for describing the phase transformation, oxidation kinetics, elemental diffusion and mechanical deformation. The numerical simulations reveal that the oxide roughness is not only affected by chemical and mechanical properties but also the geometric features. By changing the initial surface morphology, the oxide roughness is significantly reduced, which would be a very effective and simple method in related industrial application.