Development of a macroscopic shear during sheet forming of an Al-Mg alloy

Conference · · TMS (The Metallurgical Society) Paper Selection; (USA)

OSTI ID:5311291

Newman, K E; Bird, J E ^[1]

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1. Purdue Univ., West Lafayette, IN (USA)

Strain localization during sheet forming leads to the formation of a trough of rapidly thinning material or local neck. Metal flow during the onset of necking is usually envisaged as nonuniform over the scale of the sheet, but microscopically homogeneous. Experimental observations made during flow of 5182-0 aluminum sheet do not support this assumption. Slip offsets seen during plane strain flow show that, prior to local necking, strain concentrates within a grain on a single crystallographic lane. As flow continues, the density of large slip offsets markedly increases. Offsets link along directions of zero extension to create bands of high macroscopic shear. This process was first reported by Hahn and Rosenfield in studies of stretch bending, but has been largely overlooked. In 5182-0 sheet much of the flow during local necking occurs in bands of macroscopic shear located at neck boundaries. Shear within these bands leads directly to sheet failure.

• OSTI ID: 5311291
• Report Number(s): CONF-840909-; CODEN: TMPSA
• Journal Information: TMS (The Metallurgical Society) Paper Selection; (USA), Vol. 56; Conference: TMS-AIME fall meeting, Detroit, MI (USA), 16-20 Sep 1984; ISSN 0197-1689
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
SHEAR PROPERTIES
MAGNESIUM ALLOYS
SHEETS
FABRICATION
CRYSTAL STRUCTURE
GRAIN BOUNDARIES
SHEAR
SLIP
SOLIDS FLOW
STRAINS
ALLOYS
FLUID FLOW
MECHANICAL PROPERTIES
MICROSTRUCTURE
360101* - Metals & Alloys- Preparation & Fabrication
360103 - Metals & Alloys- Mechanical Properties