Effects of roller path and geometry on the flow forming of solid cylindrical components

Flow forming is used mainly to produce thin walled high precision tubular components. Due to the flexibility and low tool load requirement, the process is capable of being extended to the manufacture of shapes from bulk raw material, such as solid bar ingot, cast and forged preforms. In the work reported in this paper, a simple flow forming facility was established to enable the effects of roller path and geometry, on the flow of metal, to be examined. An FE model has been developed to simulate the process, based on experimental conditions. The results show that, for a cylindrical roller moving axially along a work-piece, metal moves predominantly in a radial direction, forming a flange. When a roller with a rounded contact region, 'nosed', is used, the metal flow is predominantly axial. Radial roller movement results in the formation of a 'cup' or a 'boss' on the end of the work-piece. The dimensions of the feature depend on the roller geometry, feed rate and amount of deformation. The results illustrate the ability of flow forming to be used for production of shapes of thin section, which would be difficult and expensive to be made by press forming.