Prevention of thin flash formation in the flashless forging of aluminium under consideration of industrial process parameters and variation of tool-integrated sealing concepts

• Applicant: Dr.-Ing. Malte Stonis
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2020 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 446183957

The use of flashless forging in the aluminium forging industry is significantly complicated by the formation of thin flash. Due to its good flow properties, aluminium tends to flow into flow gaps, such as those that exist between punch and die in flashless forging. The formation of thin flash reduces the advantages of flashless forging and prolongs the process chain due to machining post-processing. The challenge is to develop methods to predict and prevent thin flash formation. From the preceding project, on which this transfer project is based, new questions and challenges arise for the prognosis of thin flash formation in industrial processes and the avoidance of thin flash at different tool gap orientations. In the preliminary project, the results were generated that a prediction of thin flash formation is possible and that a tool-integrated sealing concept is suitable for avoiding thin flash. However, these results are not sufficient for industry-related processes because industry-related parameters such as input material tolerances, inconstant temperature control or different tool gap orientations were not taken into account. The results generated from the preliminary project on thin flash prognosis and seal development are to be transferred to industrial processes within this transfer project. The aim of the proposed transfer project is therefore to avoid thin flash formation by varying tool-integrated sealing concepts and to predict thin flash formation taking into account industrial process parameters for flashless forging of aluminium. In order to achieve this goal, we are cooperating with our application partner Otto Fuchs KG. For this purpose, a systematic investigation of the thermal loads, the stress states and the material flow vectors at the tool gap will be carried out in a test tool with four universal tool gap orientations, which will be considered locally. Global process parameters which influence the local influences at the tool gap, are varied. Only on this basis a sealing concept can be meaningfully developed. In order to avoid thin flash, different sealing concepts are developed according to the industrially used tool variants and their sealing effect is investigated. After analysis of the results and selection of a suitable sealing concept, the feasibility of two industry-related investigation tools for the application partner is to be investigated. Finally a new prognosis model can be developed, which is based on material flow vectors and enables predictions for industrial processes. In addition, application-oriented design model for the design of sealings to avoid thin flash will be developed.

• DFG Programme: Research Grants (Transfer Project)
• Application Partner: OTTO FUCHS KG
• Co-Investigator: Professor Dr.-Ing. Bernd-Arno Behrens