Novel Experimental Set-Up to Test Tubes Formability at Elevated Temperatures

In the last ten years, the automotive sector presents large interest for light alloys tubes for structural and body car parts to reduce CO2 emissions. Tubes hydroforming is one of the most popular processes to obtain complex parts by using liquids as active part of the dies (i.e. water-or oil-based emulsions) with reduced costs of equipment and machines. However, when elevated temperatures should be used to increase the material formability, hydroforming processes are strongly limited due to the boiling point of liquids. The use of gas at elevated temperature in the so-called Hot Metal Gas Forming process (HMGF) has shown promising capabilities thanks to the increased formability and the possibility to form parts with lower pressures. The paper focuses on a novel experimental set-up to evaluate the tubes formability at high temperatures. Tubes are heated by electric current and air in pressure is used to form the material. Aluminium alloy AA6060 tubes specimens were used to test the experimental equipment and evaluate temperature and pressure ranges able to shape the material.