On the flow stress and activation energy for low-temperature deformation

Abstract

Seeger has interpreted the low-temperature flow stress of pure metals as the sum of a ‘long-range’ interna] stress and a component from local obstacles. Feltham has proposed a different empirical equation, which does not invoke internal stresses. It is shown here that Seeger's equation is more readily interpreted and that it can lead to a value of the intrinsic dislocation-obstacle interaction energy. Feltham's equation gives only the total internal energy of activation, which is the sum of this and an unknown ‘long-range’ component. The two energies were confused in his original paper.