Equal‐channel multiple angular extrusion of polyethylene

The effect of accumulated deformation and deformation routes in the course of equal‐channel multiple angular extrusion (ECMAE) on physical and mechanical properties of polyethylene (PE) differed in molecular mass (MM) has been studied. As deformation routes, route C (shear planes are parallel, and the simple shear direction of every deformation zone is changed through 180°) and route E (shear planes are turned through ±45° around the extrusion axis and the normal to the axis, and simple shear direction is changed through 180° or ±90° with respect to the deformation zone) were selected. It has been shown that ECMAE provides the increase of microhardness H , modulus of elasticity E , and tensile strength σ T up to 4.5 times with strain at break ε b staying practically at the level of ε b of the initial material. The value of the effects achieved depends on MM, accumulated deformation and the selected deformation route. The best set of physical and mechanical characteristics was observed in the case of route E. The observed effects are related to the formation of a special orientation order and increased degree of crystallinity of extrudates. According to SEM data, route C results in mostly uniaxial orientation of macrofibrils at an angle of 35° to the direction of extrusion, and formation of a part of tie fibrils and macrofibrils oriented perpendicularly to the main orientation. The route E produces biaxial orientation of macrofibrils. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013