THEORETICAL-STUDY OF THE NONLINEAR ANELASTIC INTERNAL-FRICTION PEAKS ASSOCIATED WITH DIFFUSION OF SOLUTE ATOMS IN DISLOCATION CORE

Based on the dislocation kink atmosphere model, the longitudinal and t ransverse core diffusion equation of solute atoms was formulated. The relaxation time and the relaxation strength associated with the diffus ion processes under quasi-static stress were computed by solving the d iffusion equation analytically, and were found to be nonlinear with re spect to the applied stress. The theoretical internal friction curves versus temperature and strain amplitude were calculated by solving the diffusion equations with numerical method and manifestation of these curves conform to the experimental results previously obtained.