Numerical investigation of strain distribution during cyclic expansion extrusion (CEE)

Strain distribution of Al 1100 was numerically investigated during cyclic expansion extrusion (CEE) process using finite element method (FEM). Die angle, corner fillet radius and die chamber diameter were considered as die parameters and friction factor and number of passes as process parameters. The effects of these parameters were investigated on the effective strain and strain homogeneity in CEE process. Results showed that the decrease of friction factor along with the increase of die angle, corner fillet radius and number of passes lead to more homogeneous strain distribution while chamber diameter has an optimal effect on the homogeneity. Material flow diagram of the deformation zone demonstrated that shear strains have a significant contribution to accumulated effective strain especially adjacent to the outer region of the sample. In comparison, in the central region of the CEE processed sample, normal strains exist as a dominant deformation route. Also, the results revealed that all the parameters except corner fillet radius (r) influence on the equivalent strain value.