Strenghening of Nickel deformed by high Pressure Torsion

Autor(en)

H.W. Zhang, Xiaoxu Huang, Niels Hansen, Reinhard Pippan, Michael Zehetbauer

Abstrakt

The strength of a deformed metal depends on the content of high angle boundaries, low angle dislocation boundaries and the dislocations between the boundaries. High angle boundaries contribute by Hall-Petch strengthening, whereas for the low angle dislocation boundaries and dislocations between boundaries the strengthening is proportional to the square root of the dislocation density. Based on an assumption of additivity of these contributions, the flow stresses of metals deformed by cold rolling have been calculated successfully. In the present investigation pure Ni (99.9%) has been deformed by high pressure torsion (HPT) to von Mises strains of 0.9, 1.7, 8.7 and 12. The strength of the HPT Ni has been determined by Vickers microhardness (HV) measurements and the microstructural parameters have been determined by transmission electron microscope (TEM) in the longitudinal section. HPT has been compared with deformation by cold rolling and torsion based on the structural evolution with strain and the stress-structure relationship. Based on an assumption of a linear additivity of boundary strengthening and dislocation strengthening, good agreement has been found between the calculated and the experimental flow stress.

Organisation(en)

Physik Nanostrukturierter Materialien

Externe Organisation(en)

Technical University of Denmark (DTU), Riso National Laboratory, Österreichische Akademie der Wissenschaften (ÖAW)

Journal

Materials Science Forum

Band

584-586

Seiten

417-421

Anzahl der Seiten

5

ISSN

0255-5476

DOI

https://doi.org/10.4028/www.scientific.net/MSF.584-586.417

Publikationsdatum

2008

Peer-reviewed

Ja

ÖFOS 2012

103023 Polymerphysik, 210006 Nanotechnologie, 103018 Materialphysik

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/805a189f-3250-4470-96b4-bd11b14ac7d9