Solid-Solution Hardening

Abstract

The temperature and concentration dependences of the yield-stress are determined in the Cu/Zn system with polycrystalline brasses (0.03 to 1.0 at % Zn) and high-purity copper of the same grain size between 15 and 300 K. The data, as well as similar ones on other dilute copper alloys, given in the literature, are found to be well accounted for by the ‘kink-pair-formation’ model of solid-solution hardening, originally developed for concentrated solid solutions. At temperatures at which diffusional forms of recovery are absent, the model is shown to be applicable at all concentrations, with possible exceptions at levels below about 10−2%, and allows for the influence of work-hardening due to dislocation, present in the metal also in its solute-free ‘ground state’, on the process of solid-solution hardening. The kink-pair nucleation process is examined in detail.