Equal channel angular extrusion of soft solids

The influence of rheological properties of processed materials on deformation heterogeneity has been studied for the viscous flow of plasticine during equal channel angular extrusion (ECAE) through a rectangular die 2θ = 90° without any external rounding φ = 0°. To perform the physical simulation of ECAE a hydraulic workbench and a plexiglass split die were fabricated. Application of an experimental circular grid technique for planar flow of plasticine billets allows us to investigate the formation of turbulence elements and a material dead zone. Theoretical material flow patterns, the characteristics of deformation non-uniformity, flow lines, the flow velocity fields, energy-power parameters and dead zone formation in the physical simulation of the ECAE in a rectangular die have been determined with a numerical finite-difference solution of the Navier-Stokes equation in the curl transfer form for the planar flow of viscous incompressible continua. Good agreement between theoretical and averaged experimental results was found. The legitimacy of an existing analogy between viscous liquid flow and polycrystalline plastic flow during ECAE has also been analyzed. This proposed technique may be useful when applied to the analysis of polymer flow with severe plastic deformation.