The longitudinal and transverse core-diffusion equation for solute atoms was formulated on the basis of the dislocation kink atmosphere model. The relaxation time and the relaxation strength which were associated with these diffusion processes under a quasi-static stress were calculated by solving the diffusion equation analytically. They were found to be non-linear with respect to the applied stress. Theoretical internal friction curves, as a function of temperature and strain amplitude, were calculated by solving the diffusion equations using numerical methods. These predictions agreed with experimental observations.

Theoretical Study of the Non-Linear Anelastic Internal Friction Peaks Associated with the Diffusion of Solute Atoms in Dislocation Cores. Q.F.Fang, T.S.Ke: Journal de Physique IV, 1996, 6[8], 273-6. See also: Physica Status Solidi A, 1996, 158[2], 405-17