Numerical calculation of the thermal load during the thixoforming of steel and of the tool life.

• Applicant: Professor Dr.-Ing. Bernd-Arno Behrens, since 10/2017
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2016 to 2021
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 299534929

The forming of metals in the semi-solid state is due to the complex load profile high demands on the tools used. In addition to the mechanical stress the shaping tools are exposed to extreme temperature change stresses that result from the initial temperature (between the solidus and liquidus) of the alloys and in the maximum preheat temperature of the tool frame. In the case thixoforming of steels the processing temperature is about 1300-1500 °C while the mold preheat temperatures are limited to about 300-500 °C, since the machine environment consists mostly of steel. There are also loads of corrosive mold surface, in particular through the melting phase of the semi-solid alloys. Furthermore, there is a tribological attack by the solid-phase fraction during forming or by the solidified component during removal from the mold.The tools and tool costs have a significant share of the thixoforming the total cost of the part to be manufactured. One approach to cost reduction is increasing the tool life. An important contribution to this is taking the tool wear into account by using the finite element simulation during the process design and the tool design. The prediction of tool failure allows the increase of tool life through a customized process and tool design.The emphasis in the proposed funding period is the prediction of tool failure due to thermal-mechanical Thixoforming the fatigue. A realistic depiction of material behavior is necessary. Therefore, a two-phase model for the numerical simulation of material behavior has to be implemented in a commercial FE software.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Privatdozent Dr.-Ing. Anas Bouguecha, until 10/2017