Investigation on interactions between topography, friction and wear in the tribological system tool-component in hot forging

• Applicant: Professor Dr.-Ing. Bernd-Arno Behrens
• Subject Area: Primary Shaping and Reshaping Technology, Additive Manufacturing
• Term: from 2014 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 250959581

Within the scope of this research project basic knowledge of the complex interactions between the microstructure of hot forging tools and friction between tools and forgings as well as the performance of the tools are to be investigated.At first, friction coefficients and forming forces in dependence of stochastic microstructures, tool- and part-temperatures as well as lubrication conditions will be investigated under conditions of hot forging. On that basis, suitable tools for serial forging test will be designed and investigated in terms of long life wear-performance under consideration of microstructure and the named process parameters. Acting on the assumption, that the investigation parameters are significantly influenced by the loading situation, two different kinds of forging dies with clearly varying load situations (thermal, mechanical, tribological) will be realized.Another focus of this project beside the topography-depending friction and forming force is the consistency of the microstructure against the working loads during the forming process. Based on other investigations, carried out at the IFUM, it is known that there are certain kinds of microstructures that are not directly destroyed by the forming operation in terms of flattening or roughening. Based on previous knowledge the necessary characteristics of these structures could not be defined exactly. The effect of an adequate and consistent microstructure on the wear behavior of forging dies is also not known.Furthermore, the characterization of microstructural changes of forging dies in the threedimensional case by appropriate specific values are to be investigated within this project. This will be based on the Abbott-Firestone-Graph which allows the analyses of different surface values like for example the values of DIN EN ISO 25178 (spk, sk, svk). A systematical investigation of these values for the characterization of microstructural surface changes especially in the case of increasing die wear is not existent so far. By achieving this knowledge new possibilities will be opened up to understand the interactions in the tribological system tool-forging and to apply this knowledge for different applications.

• DFG Programme: Research Grants