Stress‐Assisted Diffusion to Dislocations and its Role in Strain Aging

The kinetics of Cottrell atmosphere formation around dislocations is studied numerically. The spirit of the calculation presented here follows closely that presented by Bullough and Newman, although our conclusions about strain aging are different. We have calculated solute distributions for a number of times using the standard dislocation‐solute atom interaction potentials, − A/r and − A cos(θ)/r, for screw and edge dislocations, respectively. It is shown that for suitably strong dislocation‐solute binding and appropriate dislocation densities, a Harper‐type strain aging can be predicted on the basis of stress‐assisted‐diffusion theory without ascribing any special properties to the dislocation core regions. The place of the Harper law and the Bullough and Newman calculations in the over‐all picture of strain aging is discussed.