Berlin 2008 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
MM: Fachverband Metall- und Materialphysik
MM 29: Mechanical Properties I
MM 29.5: Vortrag
Mittwoch, 27. Februar 2008, 15:00–15:15, H 0111
New approach to design the strain hardening ability in nanostructured materials. (exchanged with MM 30.1) — •Lilia Kurmanaeva1, Yulia Ivanisenko1, Jürgen Markmann2, Jörg Weissmüller1, 2, Ruslan Z. Valiev3, and Hans-Jörg Fecht4 — 1Institute für Nanotechnology, Forschungszentrum Karlsruhe, Karlsruhe, Germany — 2Universität des Saarlandes, Saarbrücken, Germany — 3Institute of Phisycs of Advanced Materials, Ufa, Russia — 4Institute of Micro and Nanomaterials, University of Ulm, Ulm, Germany
The recent past has seen an increasing interest in studies of mechanical properties of nanostructured materials(NSM), since new methods of continuous processing of bulk NSM using severe plastic deformation were developed. NSM demonstrate superior hardness and strength, but often a limited ductility due to poor strain hardening(SH) ability. In present paper we suggest a simple method to increase the SH ability of NSM by decreasing the stacking fault energy(SFE). The microstructure and mechanical properties of nanocrystalline Pd and Pd-x%Ag(x=5,10,20,40) alloys were investigated. Additions of Ag strongly decrease the SFE of Pd. The initially coarse grained samples were processed by high pressure torsion, which resulted in formation of homogeneous ultrafine-grained structure. The increase of Ag contents led to the decrease of the resulted grain size. Consequently, the samples with larger Ag contents demonstrated the higher values of strength properties. The uniform elongation had also increased, and tensile curves exhibited larger SH. Thus we have obtained a combination of high strength and good ductility in nanostructured Pd-Ag alloy.