Regensburg 2019 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 25: Transport (Diffusion, conductivity, heat)
MM 25.1: Talk
Wednesday, April 3, 2019, 10:15–10:30, H46
Strain induced atomic transport in ultra-fine grained Nickel — •Shraddha Sevlikar1, Mayur Vaidya1, Jonathan Zimmermann2, Lishai Shoham2, Eugen Rabkin2, Gerhard Wilde1, and Sergiy Divinski1 — 1Institute of Materials Physics, University of Muenster, Wilhelm-Klemm-Str. 10, 48149 Münster, Germany — 2Department of Materials Science and Engineering, Israel Institute of Technology, Technion City, Haifa 3200003, Israel
Strain-induced atomic transport was investigated in coarse and ultra-fine grained (UFG) Nickel using the radiotracer analysis. UFG Ni was produced by high-pressure torsion (HPT) of high purity coarse-grained Ni samples using 10 rotations and 4 GPa pressure. X-ray analysis revealed a grain size of 100 nm for the HPT sample. The radioactive isotope 57Co was deposited on the sample surface with mirror-finish obtained by mechanical polishing. The HPT sample was then carefully sandwiched between tantalum foils and subjected to cold rolling to 5/20 % deformation. The tracer penetration achieved during rolling was measured by serial sectioning. A strain-induced tracer penetration was quantified and compared to thermally activated diffusion in coarse-grained and UFG Ni. Reducing the sample roughness during rolling and limiting the extent of deformation-induced porosity are identified as major challenges in developing this experimental setup. The impact of sample microstructure on deformation-induced atomic transport is discussed.