Diffusion near dislocations, dislocation arrays and tensile cracks

Abstract

Equations are developed for approximating the flow rate of mobile solutes and other point imperfections across a cylindrical surface of arbitrary radius r surrounding stationary defects such as straight edge dislocations, sharp tensile cracks and edge-dislocation pileups embedded in an infinite solid. The starting point for the calculations is Fick's generalized law which takes into account the interaction potential between the stress field of the stationary defect and the diffusing solute as well as the solute-concentration gradient. It is assumed that the initial solute concentration, c(time = 0), is uniform everywhere and that c (r = 0) = 0 for time > 0. The degree of accuracy of the approximations used in this analysis is discussed in detail. Comparisons of the calculated results with experimental data are very satisfactory.