Experimental and finite element investigation of semi-constrained groove pressing process

In this research the semi-constrained groove pressing (SCGP) process as a severe plastic deformation (SPD) method was applied on commercially pure aluminum plates. According to the principle of SCGP, a material is subjected to repetitive shear deformation by utilizing asymmetrically grooved dies and flat dies which are constrained by a channel rather than a container used in the CGP process. Each complete groove pressing pass consists of four pressing operation steps. Considering the geometry of the die, in each complete pass, a large amount of strain is induced into the specimen. In the present research the effects of the deformation passes on the mechanical properties of the specimens were tested by microhardness tests and tensile tests. In addition, in order to investigate the material flow along the grooves in the SCGP process, the finite element simulations were carried out in three different conditions (3D, 2D plane strain and 2D plane stress) for the first time. Results show that the flow stress of the material and its hardness are affected by the number of passes. Analysis of force diagrams showed that the real state of the SCGP process is a combination of plane stress and plane strain conditions.