Equal channel angular pressing of single crystal aluminum: a molecular dynamics simulation

Abstract

The equal channel angular pressing (ECAP) of single-crystal aluminum was investigated using molecular dynamics to provide insights into the deformation behavior and polycrystal formation. Three samples with different initial crystallographic orientations were processed by an ECAP die with a curvature angle (Ψ) of 20° and a channel angle (Φ) of 90° at 300 K. The samples were oriented, such that [100], [110], and [111] directions were parallel to the extrusion direction (ED). The shear strain was the predominant mode of deformation during ECAP with the presence of normal strain before entering the deformation zone due to the high compression force. The sample with [100] direction oriented along the ED showed significant grain fragmentation, the highest lattice rotation but the lowest dislocation density and shear strain, whereas the sample with [111] orientation showed the opposite results. A correlation between the number of active slip systems, the magnitude of shear strain, and grain rotation angle was observed with most of the lattice rotation occurring around the transverse direction. Furthermore, the deformation and grain fragmentation processes occurring in the deformation zone were also investigated. Finally, the model could produce results similar to the results obtained experimentally in the literature.