A coupled model of stress, creep, and diffusion in the film/substrate system

Abstract

A film/substrate system is a common structural form. In its fabrication and/or operation process, diffusion is a basic and key procedure. However, there still exist unclear points in the diffusion process, i.e., the effects of stress, creep, and interface properties. To clarify these unclear points, in this paper, a coupled diffusion model including stress, creep, and interface property is established. The obtained results indicate that compressive stress retards the diffusion of guest atoms. Meanwhile, creep reduces the retardation of diffusion through releasing the induced compressive stress, and then the concentration of the guest atoms can reach the prescribed value, which overcomes the much lower concentration predicted by the previous models without creep. In addition, interfacial diffusivity affects diffusion and the maximum stress in the film.