Dresden 2011 – scientific programme
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MM: Fachverband Metall- und Materialphysik
MM 18: Mechanical Properties I
MM 18.3: Talk
Tuesday, March 15, 2011, 14:30–14:45, IFW B
Shear band formation in sub-microcrystalline Ni — •Benoit Beausir1, Lutz Hollang1, Suhash Ranjan Dey2, Ellen Hieckmann3, and Werner Skrotzki1 — 1Institut für Strukturphysik, Technische Universität Dresden, 01062 Dresden, Germany — 2Department of Materials Science and Engineering, Indian Institute of Technology Hyderabad, Ordnance Factory Estate, Yeddumailaram-502205, Andhra Pradesh, India — 3Institut für Angewandte Physik, Technische Universität Dresden, 01062 Dresden, Germany
The stability of sub-microcrystalline nickel produced by pulsed electrodeposition without any additives was investigated during cyclic deformation at very high plastic strain amplitude of 1% at room temperature. The initial microstructure having an average grain size of 160 nm in the growth plane and a weak <110> fibre texture along the growth direction undergoes considerable grain growth during cyclic loading without significant changes in texture. After a certain number of loading cycles the specimen suddenly developed a single macro shear band. The shear band appeared in the tensile half cycle under 45° to the loading axis and acts as crack starter. Investigations in the scanning electron microscope using electron backscatter diffraction revealed that the main macro shear band consists of relaxed grains elongated along the shear plane displaying a texture induced by shear. The texture in the shear band was reproduced with the viscoplastic self-consistent polycrystal model using {111}<110> slip systems. Detailed investigations of the surrounding of the macro shear band reveal the existence of a large number of regularly spaced micro shear bands.