Die angle effect on the generated residual stresses in the inclined and final region during the aluminum extrusion

Abstract

X-ray diffraction (XRD) and the finite element technique (FET) to measure the residual stresses (RS) inside Al1060 rods produced by forming operation at three different half extrusion angles (HEA = 20°, 40°, and 60°) were applied. The results of the experimental work and FET illustrate a good convergence in terms of the relationship between extrusion force and displacement with an error ratio reaching 15 %. The effect of HEA = 20° on extrusion force is the lowest compared to others. Moreover, the behavior of the obtained residual stresses from XRD and FET is in good agreement with the existence of some variation in their values. The profile of these stresses is in a tensile state near the rod surface and a compressive state near the axis at HEA = 20° and 40°. In contrast, compressive residual stresses are obtained close to the surface and center of the extruded rod at HEA = 60°.