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 degrees, 90 degrees and 45 degrees 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 degrees specimen is smaller than in the other specimens. The nucleation of the shear bands in the 90 degrees specimen is early. Due to the shielding effect, fast-developed shear bands block the development of the neighboring smaller shear bands in the 90 degrees specimen. The spacing of the shear bands in the 45 degrees 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 degrees specimen, and the spacing of the shear bands is small. The shear bands in the 90 degrees specimen are well-developed with obvious shielding effect and the largest spacing. The 45 degrees specimen has the maximum average nucleation rate of the shear bands. Owing to the close Schmid factors of the slip systems of the 45 degrees specimen, the spacing of the shear bands in the 45 degrees specimen is still larger than in the 0 degrees specimen. (C) 2010 Elsevier B.V. All rights reserved.