Strain inhomogeneity and grain refinement in AA6063 aluminum alloy subjected to repetitive corrugation and straightening: comparison of experimental and finite element analysis

The strain distributions in aluminum alloy AA6063 resulting from Repetitive Corrugation and Straightening (RCS) at room temperature were examined experimentally and also through finite element simulation. The hardness and tensile strength of the material after every passes are reported. The local strain in the samples were determined using circle grid analysis method. EBSD images confirmed the presence of sub-grains inside the coarse grains. Hardness measurements showed non-uniform values along the length of the specimen, revealed the presence of non-uniform strain as well as grain refinement. After 8 passes, the hardness was above twice that of the starting materiali, i.e. (49 Hv in the starting material to 98Hv after 8 passes). The tensile strength increased up to 6 passes from 115 MPa to 204 MPa, and decreased beyond that due to the formation of surface cracks. Finite element analysis (FEA) was carried out under identical experimental conditions using ABAQUS 6.10 to estimate the stress strain distributions up to 10 passes. The RCS die of width ~ 3 mm and groove angle 30˚ and the flat die was designed as the discrete rigid, since the deformation on the die is of no interst. The FEA reveals that the strain increases after each passes displays consistency with the experimental results, and a lack of homogeneity in deformation.