Development of a new variant of incremental sheet metal forming using heated air

A new method of temperature-assisted incremental sheet metal forming (ISF) of lightweight materials was developed at Fraunhofer IWU. The new process enlarges the area of application of ISF. Sheets of Magnesium and high-strength Aluminum can be formed to complex geometries now. The basic idea of the new ISF process is a combination of conventional single-point incremental forming (SPIF) with an evenly distributed heated air flow under the sheet. As a result of the heated air, the whole sheet (except for the clamping area) receives approximately the same temperature. This guarantees an optimal process window for several lightweight materials. In the cases of Aluminum and Magnesium, the applicability of the new method has been verified at 250 °C. Here, the part quality was significantly better than conventional ISF results. The comparison with Aluminum parts formed at room temperature corroborated this advantage. This paper describes the development of the test rig. Due to the setup of the specifically designed test rig, the process allows an application of dies and two-point incremental forming (TPIF) as well. Afterwards the SPIF tests and their results are shown and discussed in detail. A comparison with other conventional and new forming processes shows the advantages of the new technology and its potential area of application.