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MM: Fachverband Metall- und Materialphysik

MM 18: Mechanical Properties I

MM 18.3: Vortrag

Dienstag, 15. März 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.