Research of the influence of profile factor on material flow and extrusion force in extrusion

The literature provides little information about effect of geometry of cross-section extrudate on mechanics of metal flow and extrusion force. In many studies, several formulas for calculating the extrusion force have been presented. But there is a lack of relationship in literature for calculation of the extrusion load for non-symmetrical sections. In the case of extrusion of non-circular sections, the theoretical evaluations of force, different formulas are considerably different from values assigned experimentally. Indeed, the size and shape of cross-section extrudate are the most important factor influencing on extrusion load.Shape complexity significantly influences on the extrusion load. The extrusion load is the lowest for the circular cross-section, however it increases for the square, triangle and rectangle cross-sections respectively. In this study, profile factor?s several definitions in literature are explained, a relationship between profile factor, material flow and extrusion pressure is tried to carry out. The attribute which determines the shape of the extruded cross-section (number of corners, acute and obtuse angles in extruded shape, number of axes and planes of symmetry, thickness of profiles cross-sections) influence the material flow and extrusion force.The effects of extrusion pressure variation and material flow on the tool complexity and ram speed were investigated using theoretical and experimental studies. At constant ram speed, pressure curves for more complex profiles were generally higher than those of less complex ones. Deviations from this behavior emphasize the need for an improved definition of die shape complexity. For fixed shape complexity, pressure curves are generally higher for higher speeds.