Deformation behavior of pure aluminum specimen composed of a few grains during simple compression

In this study, the grain-by-grain deformation of aluminum specimens with a few grains during simple compression is investigated experimentally. This experiment is conducted to verify the simulation technique based on the crystal plasticity model with which grain-by-grain deformation behavior can be anticipated. 99.99% polycrystalline aluminum cubes with dimensions of 3 mm × 3 mm × 3 mm is tested. By applying consecutive heat treatments, the grain size of the aluminum specimens is grown to a size with a diameter of 1–3 mm. The specimens used in this study can be classified into two types: the specimens predominated by a single grain (type1) and the specimens composed of several grains (type2). The individual surface grain orientations of the initial specimens are measured by electron backscattered diffraction (EBSD) system, and then the specimens are compressed to 70% of the initial height. The resultant deformations of the type1 specimens are then compared with the calculations based on the crystal plasticity. For the type2 specimens, finite element method (FEM) using the crystal plasticity material model is adopted to predict the complicated grain-by-grain deformations. However, as the inner grain distribution cannot be measured by EBSD in the present investigation, the experimentally observed deformations of the type2 specimens are not directly compared with the corresponding FEM predictions. Instead, the similarity between the experimental observations and the FEM predictions is compared in a qualitative manner.