An attempt to estimate the degree of precipitation hardening, with a simple model
The process of diffusion being assumed to result simply in an interchange of atoms, an estimate is made of the internal strains produced by precipitation. According to the dislocation theory these strains are responsible for the hardness of the material, and so the degree of hardening can be predicted.
Proceedings of the Physical Society, Vo. 52, 1940, p. 86-89