Differential heating forming of solid and bi-metallic hollow parts

A non-traditional material deformation method is introduced as an alternative approach to the production of parts of complex geometries. The deformation mechanism, which relies on selectively increased metal flow in locally heated regions, gives advantages to part strength and fatigue properties. Compared to closed-die forging, the reduction of heating and loading requirements has a positive effect on tool life, tool design and loading requirements. Furthermore, the method can be applied to near-net-shape production in an open-die forging environment, thus reducing the cost of the production forming dies. The work presented in this paper examines the effects of heating duration, compressed profile, and the number of forming steps on the mode of deformation. A simulation model of the differential heating forming process has been characterised, and a finite element analysis was performed using various operational parameters. Additionally, the modes of metal flow in bi-metallic hollow parts were examined both experimentally and by numerical simulations.