Relaxation in dispersion-hardened alloys by volume diffusion

Since elastic inhomogeneities are included in dispersion-hardened alloys, uniform applied stresses are disturbed in the materials. When the applied stresses have non-zero hydrostatic components, relaxation by long-range volume diffusion occurs in the dispersion-hardened alloys at high temperatures. The relaxation by the volume diffusion is discussed by taking into account the change in the Gibbs free energy of the material. The stress state inside a dispersed particle after the complete relaxation and the relaxation time to reach the equilibrium state are derived in a physically clear manner. The relaxation time obtained is compared with previous calculations by other investigators and the origins of the differences are discussed.