Inhomogeneous plastic flow investigated by X-ray absorption microtomography of an aluminium alloy containing marker particles.

By combining a synchrotron X-ray source and the microtomography technique, the displacement gradient tensor components can be measured directly throughout the volume of a metal sample containing highly absorbing marker particles to detect material flow. The present article describes application of these techniques to compression of a rectangular Al-W specimen with a central hole. The results show that the externally imposed axial displacement gradient is accommodated mainly in two 45 degrees shear bands passing through the hole. A simple deformation analysis provides insight into shear band formation.