Characterization of macroscopic local deformation behavior of thermo-mechanically graded high strength aluminum and steel alloys

Characterization of macroscopic local deformation behavior of thermo-mechanically graded high strength aluminum and steel alloys

Emad Scharifi, Sebastian Hirte, Steffen Lotz, Michael Mlynek, Ursula Weidig, Agim Ademaj, Kurt Steinhoff

Abstract. In this study, the local deformation behavior of the transition zone of thermo-mechanically graded boron steel 22MnB5 and high strength aluminum alloy AA7075 is investigated using an in-situ approach. For this aim, forming tool segments are differentially heated in order to obtain locally tailored microstructures and dissimilar mechanical properties based on the process-induced microstructural phenomena. Material strength distribution is examined by Vickers hardness measurements after thermo-mechanical processing. Tracking of the material- and geometry-dependent local deformation behavior of the resulted transition zone is performed by tensile tests coupled with digital image correlation technique. The experimental results reveal within the transition zone a characteristic reversed S-shape hardness distribution, similar to a sigmoidal curve. The local deformation characterization indicates the occurrence of plastic deformation mainly in the soft zones at the heated forming tools segments, while the harder zones at the cooled tool segments exhibit only an elastic deformation and remain undeformed. By comparing the macroscopic local deformation evolution shortly before failure, absolute strain values up to von Mises = 0.62 and von Mises = 0.28 and a distinct reduction in the area are obtained for 22MnB5 and AA7075, respectively. The occurred plastic strain pattern show the formation of shear bands after a homogenous localization at the necking point.

Keywords
Steel, Aluminium, Functional Gradation

Published online 3/17/2023, 8 pages
Copyright © 2023 by the author(s)
Published under license by Materials Research Forum LLC., Millersville PA, USA

Citation: Emad Scharifi, Sebastian Hirte, Steffen Lotz, Michael Mlynek, Ursula Weidig, Agim Ademaj, Kurt Steinhoff, Characterization of macroscopic local deformation behavior of thermo-mechanically graded high strength aluminum and steel alloys, Materials Research Proceedings, Vol. 25, pp 245-252, 2023

DOI: https://doi.org/10.21741/9781644902417-31

The article was published as article 31 of the book Sheet Metal 2023

Content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.

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