Upper-bound analysis for the combined simple shear extrusion-forward extrusion (CSSE-FE) process using a linear profile

Abstract

The combined SSE-FE PROCESS was recently known as a new severe plastic deformation (SPD) method. In this process, the die wall's unique shape can create large strains without repeating the cycle. The samples are extruded gradually using direct punch pressure and are produced with a regular cross-sectional area. In this study, the upper bound (UB) theory method is proposed for the first time to estimate the forming force consumed in the CSSE-FE technique. The UB theory analysis is investigated for the deformation of 1050 aluminum alloy with a square cross-section. Also, the CSSE-FE process was studied experimentally and numerically using ABAQUS/Explicit 6.14 software to validate the results. In addition, the effect of the friction factor ($m$), the maximum deflection angle (${\alpha }_{\max }$), and the thickness of the die outlet channel on the force consumed was investigated. The numerical results and the upper bound theory showed that by increasing the friction factor from 0 to 0.4, the force increased by about 82.24 %. In this research, the upper bound method in force prediction caused a difference of about 10.2 % greater than the experimental results. The accuracy in calculating the force using theoretical, numerical, and experimental methods can be seen from an excellent correlation between their results.