Effect of orientation on self-organization of shear bands in 7075 aluminum alloy

The spatial distribution of shear bands was investigated in the rolled 7075 aluminum alloy through the thick-walled cylinder (TWC) technique with 0°, 90° and 45° angles between the aluminum alloy cylinder axial direction and the rolling direction. Self-organization of multiple adiabatic shear bands was observed in different orientation specimens and investigated by using Schmid factor theories. The experimental results indicated obvious differences in the morphology and self-organization of shear bands for the specimens. At the initial stage, the spacing of the shear bands in the 0° specimen is smaller than in the other specimens. The nucleation of the shear bands in the 90° specimen is early. Due to the shielding effect, fast-developed shear bands block the development of the neighboring smaller shear bands in the 90° specimen. The spacing of the shear bands in the 45° specimen is much larger than in the other specimens under the similar effective strain. At the late stage, a large number of shear bands nucleate in the 0° specimen, and the spacing of the shear bands is small. The shear bands in the 90° specimen are well-developed with obvious shielding effect and the largest spacing. The 45° specimen has the maximum average nucleation rate of the shear bands. Owing to the close Schmid factors of the slip systems of the 45° specimen, the spacing of the shear bands in the 45° specimen is still larger than in the 0° specimen.