报 告 人：Prof. Wolfgang Pantleon
工作单位：Department of Mechanical Engineering, Technical University of Denmark（丹麦技术大学 机械工程系）
Dr. Wolfgang Pantleon received Ph.D. degree in Physical Metallurgy (Dr.-Ing.) with distinction from TU Bergakademie Freiberg in 1996. After his graduation, he worked at Technical University of Denmark. His research interests include Materials for fusion reactors, Dislocations, deformation microstructure and work-hardening behaviour of metals, Electron backscatter diffraction, Nanostructured materials after severe plastic deformation. Dr. Wolfgang Pantleon has published 101 publications (63 in journals, 37 in books or proceedings, one book) and 72 oral presentations (37 invited) at international conferences. The h-factor is 16. Dr. Wolfgang Pantleon was also editor of seven conference proceedings, Deputy Editor of Scripta Materialia in 2001 to 2011, and Associate Editor of Texture, Stress and Microstructure in 2006 to 2010.
Commercially pure aluminium is cyclically deformed in symmetric tension and compression while monitoring the microstructure by high-resolution reciprocal space mapping. The synchrotron technique enables resolving subgrains, orientation spread and elastic stresses in individual grains. Following four grains through 10000 tension compression cycles, reciprocal space maps were gathered after different number of cycles and through five subsequent cycles. More pronounced changes occur within individual load cycles than during an increase in number of cycles. Radial profiles revealed a characteristic behavior: the integral width follows a butterfly pattern and the asymmetry changes sign corresponding to the applied stress, but increases markedly during unloading. Based on the observation of a larger asymmetry in the unloaded state than at maximum tension or compression and the behavior of individual subgrains tracked during the cycles, necessary modification of the composite model for cyclic deformation (even in its refined version) are outlined.