An integrated approach to cost-effective process planning and equipment selection in cold, warm and hot forming

In response to customer request for forged parts, the supplier needs to determine the cost-effective process and the equipment to meet required quantity, shape and properties ensuring the production of defect-free parts. Experts layout a sequence of forming operations to transform a simple billet to a finished forging. These forming operations can be performed in different temperature regimes such as cold, warm or hot of a given material and on several equipment. The choice and design of the individual forming operations influences the need for intermediate operations such as heat treatment, coating, heating, etc. and the selection of forming equipment. It is extremely difficult and nearly impossible to evaluate all possible combinations of processes and equipment to produce a cost-effective forging, manually.; In this dissertation, a cost-effectiveness evaluation model and a solution method has been developed to address the above problem. A discriminating cost model (DCM) has been developed to measure cost-effectiveness, and a modified form of 'generate and evaluate' search methodology applied to find cost-effective solutions to produce formed parts.; A prototype computer system 'CEPESS' (Cost-Effective Process and Equipment Selection System) has been developed incorporating the developed evaluation model and solution method. The research focussed on steels for materials, presses and headers for forming equipment and processes which are cold, warm and hot combinations of the forming operations: open forward extrusion, closed forward extrusion, backward extrusion, upset and dimple. The capabilities of the CEPESS was verified by running different example scenarios. The validation of the system was accomplished by application of CEPESS to the current process of making 'outer races'. Forming trials and experiments were conducted to verify the feasibility and cost-effectiveness of the process and equipment changes recommended by the system. The system has been built using 'ICAD' and 'Lisp' with features to enable sensitivity evaluation.; The methodology developed in this research is an element of concurrent engineering where forming process planning and equipment selection have been considered concurrently with costs. The developed methodologies and system can be extended to include machining operations utilized subsequent to forming operations.