Improved mechanical anisotropy and texture optimization of a 3xx aluminum alloy by differential temperature rolling

The effects of roller temperature on the microstructure and mechanical properties of a 3xx serie aluminum alloy sheet were studied. Three temperature settings, namely, traditional rolling with low roller temperature (LTR), high roller temperature (HTR), and differential temperature rolling (DTR): different temperature of upper and lower rollers, were performed. The results reveal that among the three routes, the DTR introduces an internal shear strain, which significantly promotes the dynamic recrystallization and grain refinement. Moreover, a texture optimization from the rolling texture of {112} < 111 > to {001} < 120 > texture can be observed. The newly-formed {001} < 120 > texture has a high Schmid factor in both rolling and transverse direction (RD and TD), which contributes mostly to the improvement of the mechanical anisotropy. Compared to the LTR and HTR samples, the mechanical properties (tensile strength, yield strength and elongation) of the DTR samples in RD and TD are closer, which results in a significantly higher Erichsen value of 6.85 even without annealing. In addition, the combined experimental and calculation results indicate that the DTR sample also maintain a high yield strength due to a higher recrystallization degree and grain boundary strengthening effect. The mechanical anisotropy can be reduced by controlled grain refinement, dynamic recrystallization and texture optimization through DTR without sacrificing the strength.