A new approach for the optimisation of the shrink-fitting of cold-forging dies

Nett-shape manufacturing of engineering components is a major objective of modern material-conversion industries: relevant technologies depend on tools in which error-compensation can be effected. A novel die-design approach, known as the least squares approach, to minimise the component errors is presented. Shrink-fitting compensating die structure is employed. The errors caused by die-elasticity, secondary yielding, springback and temperature are considered in the process of minimisation. The main factors that may influence the accuracy of the optimisation procedure are analysed. The final component errors can be controlled to within a few micrometers. The approach is illustrated using axisymmetric closed-die forging.