Impact Metal Forming

Author:  Helmut Reccius, IHR, Gummersbach, Germany
Source:  Conf Proc: ICSP-8 Sept. 16-20, 2002 Garmisch-Partenkirchen, Germany
Doc ID:  2002032
Year of Publication:  2002
Abstract:  
Introduction IMF is a new forming method, working on the well known local forming principle: An impact body impinges the surface of a component. The impact energy produces a local elongation of the material. Dependent of mass, form and velocity of the impact body as well as the conditions of the component, e.g. material, part thickness, the local elongation causes a shape change. That principle follows different techniques, for example forging or peen forming [1]. In general these techniques can be distinguished whether a holder-up, e.g. an anvil for forging, is necessary or not. The anvil is not necessary, if the mass of the impact body in comparison to the component is very low and the speed of the impact body is very high. This principle is used for peen forming, when balls or similar elements are shot on the surface of the component. To reach a forming effect, the conditions of the peening process (type of grain, velocity, size, material) have to be optimised. The same idea is realized in IMF: An impact body with low mass (> 0.2 g) is accelerated by a motor driven spring on a closed guideway and impinges with high velocity (> 10 m/sec) on the component surface. Figure 1. shows some principle spring designs.