Effect of thermal cycling process parameters on recrystallization kinetics for processing of fine-grained pure copper

The present work developed a two-step thermal cycling technique for processing of fine-grained pure copper for improved properties. This included initial annealing of specimens followed by heavy cold rolling and a series of heating and cooling cycles. The study investigated the important microstructural changes occurring in the cold deformed grains in the absence of phase transformations. A major interest of the present research was to closely describe the effect of thermal cycling parameters on the recrystallization and grain growth kinetics for processing of fine-grained structure. The study determined the optimum values of process parameters for the developed thermal cycling route including the extent of cold deformation, annealing temperatures, holding periods, and the number of thermal cycles. The thermal cycling process produced closely distributed fine grains with bi-modal microstructure leading to increased hardness and strength without any significant loss in electrical conductivity.