Investigation of flashless forging of aluminum hollow parts with large undercuts

Theme Forming technology
Project title Investigation of flashless forging of aluminum hollow parts with large undercuts (SmW)
Project duration 01.08.2009 – 31.12.2011
The aim of the project is to develop the basis for forging flashless and hollow lightweight aluminum components with large undercuts. The results will contribute to extend the use of forging parts from bulk metal parts to thick walled hollow parts. The method is based on the principle of flashless precision forging, instead of bulk material hollow parts are used. The cavity is filled with a medium under pressure which supports the forming process on the principle of hydroforming.

Publications about the project

Hydroforming is often used to conduct forming of thin-walled hollow parts made of tubes. In order to form thick-walled hollow parts made of Aluminum a process has been developed, to form such parts. These parts are in a heated state. The forming has been made by help of an active fluid medium on a hydraulic deep-drawing press. For investigation purpose an example process has been designed for a trial part. This process has been analyzed by FEA and verified by laboratory tests.

hydroforming, forging, tubes, aluminium, FEA

Lightweight design of cars is one way to reduce fuel consumption and increase the range of cars. This is an important factor to attain the EU limit values for CO2 emissions for vehicles and thus to avoid penalties for exceeding these limits as of the year 2012. The growing number of uses for high-strength steels or lightweight structures are adequate means to reduce weight. At IPH - Institut für Integrierte Produktion Hannover gGmbH a method to produce hollow profiles made of aluminum was developed. This method, called hydroforging, combines flashless forging and tube hydroforming. It allows the production of thick-walled hollow aluminum profiles with undercuts without the need for complex tool kinematics. The forging is supported by an active medium. A tool concept has been developed using the drives of a hydraulic press with die cushion. With this tool, various part geometries shall be produced and analyzed. To produce the tools' interior pressure and the forming pressure, liquid tin as an incompressible active medium is used. The forming is initiated by upsetting the aluminum profiles and supported by the active medium, so that the profile is pushed against the cavity of the dies. The process was designed based on simulations and will be verified by practical experiments. This paper describes the development of the forging process with an active medium.

hydroforming, forging, tubes, aluminium, FEA


The project no. 137625033 received funding from the German Research Foundation (DFG).

Your contact person

Mareile Kriwall

Manager process technology