Title: Material formability at cold upsetting of cylinder by different plates as a base for metal forming technology design

Authors: Miroslav Plancak, Dragisa Vilotic, Dejan Movrin

Addresses: Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia. ' Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia. ' Faculty of Technical Sciences, University of Novi Sad, Trg Dositeja Obradovica 6, 21000 Novi Sad, Serbia

Abstract: Upsetting of cylinder by flat dies is one of the elementary bulk metal forming operation. But, upsetting of cylinder can also be performed by the dies different than flat, which influences the stress-strain state and material formability. This paper describes the formability analysis at cold upsetting of cylinder and hollow cylinder by different plates (flat plates, hollow plates and hollow plates whit concentric channels). The aim of this investigation is determination of influences of die and workpiece geometry on stress-strain state and material formability. The obtained results are integrated in formability limit diagram, which represents relationship between limit strain (φ_e1) and stress indicator (ß). Experimental investigations have been performed on steel specimens C4146 (EN: 100Cr6). The determined diagram is a base for metal forming technology design, as it enables to predict damages of material structure during plastic deformation.

Keywords: material formability; forming limit curve; bulk metal forming; cold upsetting; cylinders; stress; strain; plastic deformation; damage.

DOI: 10.1504/IJMMP.2009.031596

International Journal of Microstructure and Materials Properties, 2009 Vol.4 No.5/6, pp.626 - 639

Published online: 12 Feb 2010 *

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