Berlin 2015 – wissenschaftliches Programm
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MM: Fachverband Metall- und Materialphysik
MM 14: Transport I: Diffusion
MM 14.3: Vortrag
Montag, 16. März 2015, 16:15–16:30, H 0107
Investigating the effect of severe plastic deformation on nickel using radiotracer diffusion and microstructural analysis — •Simon Trubel1, Sergiy Divinski1, Martin Peterlechner1, Gerrit Reglitz1, Matthias Wegner1, Christian Simon1, Ehud Almog2, and Gerhard Wilde1 — 1Institut für Materialphysik der WWU, Münster, Deutschland — 2Technion, Haifa, Israel
Ultrafine grained and nanocrystalline materials produced by methods of severe plastic deformation (SPD) have roused a growing interest in science and technology. Previous experiments on Nickel of 99.6% purity revealed ultra-fast diffusion rates in ultrafine grained material severely deformed via equal channel angular pressing (ECAP) [1] and high pressure torsion (HPT). This study reports the effect of pre-annealing of ECAP-processed Ni on the grain boundary characteristics and the thermal stability of microstructure. Grain boundary self-diffusion has been analysed using the 63Ni radioisotope in combination with high-precision parallel grinding. The results of the diffusion measurements and of measurements by electron backscattered diffraction (EBSD) and transmission electron microscopy (TEM) are discussed with respect to modifications of grain boundary structures under different routes of SPD processing. Additionally, cold rolled Nickel is investigated as another variant of severely deformed material that has been processed along a different deformation pathway in order to gain insight into the formation conditions of the grain boundaries that act as ultra-fast diffusion paths after SPD treatment. [1] S. V. Divinski, G. Reglitz, H. Rösner, Y. Estrin, G. Wilde. Acta Materialia, 59, 1974 (2011).