A study has been made of microstructure refinement in copper-based solid solutions arising from large strain deformation. Plane strain machining is used to introduce different levels of strain and temperature in the solid solution chips, while the solute type and concentration is varied to change the stacking fault energy (SFE) of the solid solutions. The microstructure, hardness and annealing characteristics of the chips are characterized as a function of the deformation parameters (strain, temperature) and SFE.