An exploration of microstructural in-homogeneity in the 6082 Al alloy processed through room temperature multi-axial forging

Abstract

In the current work, open die multi-axial forging (MAF) of 6082 Al alloy was performed at room temperature. The resulting microstructure and mechanical properties were found to have a gradient from the periphery towards the center. The resulting inhomogeneity was quantified with the help of electron backscattered diffraction, X-ray diffraction analysis, hardness and tensile strength measurement. The recrystallized grains were found after the partition of inverse pole figure (IPF) maps by using the criteria (Grain orientation spread<1°& boundary misorientation angle>15°). The sub-grains were found by partition of the IPF-maps by using the criteria (Grain orientation spread>2° & 2° < Grain rotation angle<15°). The high driving force (dislocation density) available at center of the MAF sample was responsible for the increase in sub-grains size up-to micrometer regime as well as increase in the volume fraction of recrystallized grains. The presence of a strong deformation texture (Goss ({110} 〈001〉)) and the recrystallized texture (Rotated Cube texture ({001} 〈110〉)) were observed, as we proceed towards the center of the MAF sample.