Computer aided design and manufacture of streamlined extrusion dies

摘要

Extrusion is one of the widely used metal forming processes. The extrusion process is carried out conventionally using a shear faced die, but shear faced dies have many practical problems such as a dead metal zone, more redundant work, breaking of whiskers and above all the design of a shear die is done based on experience. To eliminate the above problems, a new approach of designing the die known as a streamlined die is tried here. The streamlined extrusion die is designed based on the principle of constant area reduction over the length of the die. In this, a uniform flow of metal is ensured from the surface to the core and this can be a more scientific approach of die design. Many methods ace available in the literature to design the streamlined extrusion die such as cubic polynomial curves, the area mapping technique, the line, mapping technique and the use of a genetic algorithm. For solving the problem of die design Stokes' theorem is suggested, but a new approach of transforming the peripheral point on the surface of a cylinder to the corresponding point on the extruded square is obtained by an analytical method. An attempt is made to identify an analytical solution for designing a streamlined extrusion die for a square cross-section.