Abstract
In forging operations, an appropriate die-shape determination is of vital importance. This paper presents a new system for automatic determination of the intermediate die surface in multi-step forging based on an optimization technique. In the first stage of the process, using a unique design parameter which generates the shape lying between the pre-form and the final product, a preliminary die surface, shich gives the lowest forging load within the design space, is determined. In the second stage, further detailed optimization by local search is performed around thus obtained solution at the first stage. Constraints for avoiding material defects such as folding and cracking during forging are considered. The validity of this method has been confirmed by applying it to the die design for an axisymmetric backward extrusion problem.