TP2: Thermomechanical characterization and microstructural analysis of the interaction of shear bands with elements of the microstructure

点击翻译按钮获取中文摘要

Adiabatic shear band formation occurs as a deformation process in metallic materials particularly at high deformation rates. Shear band formation is characterized by energy dissipation during plastic deformation, which is associated with a local temperature increase that leads to local softening and, finally, to an increasingly pronounced localization of the subsequent deformation. A detailed understanding of shear band formation is interesting from the point of view of materials science, experimentally challenging and also highly relevant from a technological point of view, especially in the context of high-speed blanking. A key objective of this research project is to investigate the influence of different initial microstructures on the formation and growth of different types of shear bands in unalloyed and low-alloyed steels, respectively, as well as in a non age-hardenable aluminum alloy. The project furthermore aims at developing criteria for the evaluation of the shear tendency of the investigated materials during high-speed blanking, with a special focus on strain rate sensitivity, strength and thermal conductivity of the materials. In particular, the aim is to understand the relationships between the initial microstructures and the resulting shear band properties. The focus is not only on the macroscopic investigation of the mechanical behavior but also on the microstructural and micromechanical characterization of shear bands, with additional consideration of the influence of different stress states. Moreover, the cutting surfaces produced by high-speed blanking will be systematically characterized, and conditions for tailoring well-defined surface properties will be identified. Consequently, a significant contribution will be made to the central research goals of the Research Unit by the development of a clear understanding of the relevant microstructural mechanisms – from the initiation of an adiabatic shear band, via its growth and interaction with microstructural features, to the functional surface generated during high-speed blanking.