MICROSTRUCTURAL STUDY AND RECRYSTALLIZATION KINETICS OF DEFORMED COMMERCIAL COPPER WIRES

Abstract

This work aims to investigate the microstructure after the cold-wiredrawing process of commercial copper and its recrystallization kinetics under isochronal annealing. In this paper, the samples of commercial copper wires were analysed after six different reductions by a wiredrawing at room temperature. Optical microscopy, Scanning Electron Microscopy (SEM), and DSC was used as characterization techniques. The samples were annealed under Argon atmosphere with four different heating rates by using DSC. The Kissinger, Ozawa, Boswell, and Starink methods were used to determine the recrystallization kinetics. The results showed that the cold-wiredrawing had caused the elongation of grains along the main axis of the wires also showed the existence of slip bands. It has been found, on the one side, that the recrystallization temperature increased and shifted to higher temperatures as the heating rate increased, which means that this reaction is thermally activated; on the other side recrystallization temperature clearly shifted to lower temperatures as the deformation increased, which indicated that recrystallization is profoundly enhanced by high deforming. We noted a decrease in the activation energy values when the reduction increases, the activation energy for the most reduced materials were lower than that in the less reduced wires.

Keywords

• commercial copper
• recrystallization
• activation energy
• isochronal annealing
• optical microscopy
• DSC