Deformation-induced surface roughening of an Al-Mg alloy

Abstract

We analyze the deformation-induced surface roughening of an Al-Mg alloy. One aspect of our work is an effort to model the exact roughening behavior of a mesoscale-size specimen that contains a small number of grains. Such a specimen is obtained using prestrain, recrystallization annealing and subsequent machining. It contains one layer of grains through the thickness and is tested under uniaxial tension. A laser confocal microscope is then used in order to measure the surface profile of a deformed specimen. We apply crystal plasticity finite element method to a voxel model of a given specimen. The exact arrangement of grains in the voxel model is reconstructed from a pair of electron backscatter diffraction (EBSD) scans using a custom-developed shape interpolation procedure. The material properties of the Al-Mg alloy are found using an efficient black-box optimizer. The exact shape of the deformed specimen wasn't fully captured, however results on average surface roughness show good matching between model and experiment.