Tool life and tool quality in bulk metal forming

Due to their intermediate position between machine and workpiece, tools represent the interface of the manufacturing system to the process. Near net shape production, new materials and techniques are the new challenges in metal forming and above all in tooling. A significant economical effect can be achieved through an increase in the service time of tool elements, as well as through proper tool management strategies. The greatest problem connected with the preliminary estimation of tool life is the large dispersion of tool lives for the same construction of tool. The uncertainty in estimating the expected service time of tools and thus the tooling costs/piece is caused by the enormous variety and confluence of damaging factors, the factory-specific character of tool life and the stochastic phenomenon of tool failures. From the confluence of aspects influencing tool life it is clear that there is no general recipe for increasing tool life and tool quality. Each of the influencing aspects contains some possibilities for increasing the service time of tools. This paper provides some examples of tool design and tool manufacturing and points out that a knowledge-based approach imitating the activity and knowledge acquisition of human experts can be the bridge between CA-techniques and human experience in the prediction of expected tool life.