Influence of anvil alignment on shearing patterns in high-pressure torsion

Authors: Huang, Y., Kawasaki, M. and Langdon, T.G.

Journal: Advanced Engineering Materials

Volume: 15

Issue: 8

Pages: 747-755

eISSN: 1527-2648

ISSN: 1438-1656

DOI: 10.1002/adem.201200363

Abstract:

A two-phase duplex stainless steel was used as a model material in order to investigate the development of flow patterns when processing using high-pressure torsion (HPT). The results show that double-swirls are visible on the disc surfaces when processing with controlled amounts of anvil misalignment but not when the anvils are in an essentially perfect alignment. There are also shear vortices visible on the disc surfaces when processing with controlled amounts of misalignment but not when using perfect alignment. These results demonstrate the need for exercising significant care when processing discs by HPT. Prior to introducing torsional straining, it is important to ensure that the upper and lower anvils are in good alignment to within ≈25 μm. High-pressure torsion is now a major processing method for the production of metals with ultrafine grain sizes. Experiments using a two-phase duplex stainless steel show that the flow patterns on the disk surfaces vary depending upon the amount of anvil misalignment. Specifically, shear vortices are visible when processing with a misalignment of x = 100 μm but not when the anvils are in perfect alignment. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Source: Scopus