Microstructure, texture and mechanical characteristics of asymmetrically rolled polycrystalline copper

• Grain refinement and intragranular fragmentation result after asymmetric rolling
• Microhardness and stored energy are increased after asymmetric rolling.
• Texture rotation around transverse direction is observed and predicted by modeling.
• Sample bending was correctly predicted by finite element method.
• More small angle and less high angle boundaries occur after asymmetric rolling.

The process of asymmetric rolling, as an alternative to the symmetric rolling, attracts attention of many researchers and technologists. Asymmetric rolling can modify rolling process parameters like normal forces and torques, sample shape (by bending) or power requirements. It can also change material properties. The enhanced shear deformation, characteristic for this process, leads to microstructure refinement, increase of material strength and texture rotation. Asymmetric rolling can be realized by a modification of existing rolling mills, therefore its industrial application is possible at a relatively low cost. In this aspect, the case of a moderate rolling asymmetry and moderate deformation in one rolling pass was examined; these parameters can be attained on typical industrial rolling mills.The aim of the present study is to characterize this process and resulting material modifications in the case of the polycrystalline technically pure copper. The EBSD, XRD, calorimetry and microhardness measurements were performed. Texture and mechanical characteristics were studied using a crystal deformation model and the finite element method. The latter calculations enable to optimize some parameters of asymmetric rolling process.