Upper-bound analysis for the automation of open-die forging

The automation of open-die forging systems can be attractive for small batch manufacture of medium-size parts where they can compete against a number of machining processes. The introduction of new manufacturing systems and the associated work-in-progress minimization technique prompts a consideration of the use of open-die forging for incremental profiling and shaping processes. In order to develop an automated open-die forging process it is essential to be able to predict the shape changes occurring at each step. Therefore a general computerized methodology is proposed for small batch manufacture via a theoretical model, producing rapid predictions of metal flow for continuing incremental deformation. This paper reviews the open-die forging process in this context as a part of a computer-controlled robotics flexible forging system for the economic production of small-batch quantities. The metal flow in open-die forging is analyzed through a number of upper-bound solutions and the basis of an on-line analytical modeling system, together with experimental correlation and a planning system, is presented to produce bar profile features.