Mechanical properties, microstructure, and texture evolution of copper sheets subjected to differential speed rolling process

Abstract

Copper sheets were subjected to differential speed rolling (DSR) at roll speed ratios (RSRs) from 1 to 3. The effects of the RSR on the yield strength, uniform strain, microstructure, and texture evolution in the copper sheets were investigated. The grain refinement and uniformity were obviously enhanced, the yield strength and uniform strains increased slightly, and the shear texture components were further widely distributed when the RSR was increased up to 2. At RSR=3, the yield strength decreased, with a distinct increase in the uniform strains due to dynamic recovery and recrystallization as a result of the steep reduction in the geometrically necessary dislocation (GND) density and the grain orientation spread (GOS), thereby increasing the work hardening coefficient (n) and decreasing the work hardening rate (θ).

The Cold Angular Rolling Process of Copper Sheets: Unraveling Plastic Deformation Behavior and Unveiling Microstructural Transformations

“…The evaluated n values are similar to the reported values of n = 0.085 for a pure Cu during testing in tension at 2.8 × 10 −4 s −1 after cold swaging for 10.1–13.5% [ 83 ] and n = 0.07–0.08 for a commercial purity Cu under tension at 1.0 × 10 −3 s −1 after asymmetrical rolling for a strain of <1.0. [ 84 ] Low strain hardening exponent after cold rolling indicates decreased formability of the sheet metal, thereby leading to stress localizations and necking. [ 85 ] The full‐width Cu sheet showed lower n values than the half‐width ones, and the lower formability of the full‐width sheets supports the maximum possible CARP of 2 passes under the present processing conditions, while there is no tendency to further decrease n with increasing CARP passes.…”