Grain Refinement and Mechanical Properties Enhancement in Cross Roll Rolled Pure Copper

Abstract

To evaluate the microstructures and mechanical properties in cross-roll rolled pure copper, comparing with conventionally rolled materials, this work was carried out. Pure copper (99.99 mass%) sheets with thickness of 5 mm were cold rolled to 90% thickness reduction by cross-roll rolling (CRR) and subsequently annealed at 400 °C for 30 min. Also, to analyze the grain boundary character distributions (GBCDs), electron back-scattered diffraction (EBSD) technique was employed. As a result, the cold rolled and annealed materials consisted of significantly refined grains than that of the initial material (100 μm). Especially, the CRR processed material showed more refined grain size (6.5 μm) in average than that (9.8 μm) of conventional rolling (CR). These grain refinements directly affected an increase in mechanical properties. Furthermore, the texture development in CRR processed material, in which <112> grains were densely distributed in the normal direction (ND), was more effective to enhance the yield strength.