Preform design for precision forging of an asymmetric rib-web type component

Rib-web type aerospace and aircraft components in general have small fillet and corner radii with zero draft angles. In precision forging of such a component, the preform should be designed with a great care in order to produce appropriate metal flows. An improper preform invokes defects of underfilling and folding in the component with excessive stresses and wears in the forging equipments and dies. In the present study, it was attempted to design the preform for precision forging of an asymmetric rib-web component by predicting metal flows with the rigid-plastic finite element analysis. It was found that the key to the preform design is a proper distribution of the material, which was successfully achieved by a thorough investigation of metal flow and volume change from the result of the finite element analysis.