Microstructural observations and tensile fracture behavior of FSW twin roll cast AZ31 Mg sheets

A. Dorbane, G. Ayoub, B. Mansoor, R. F. Hamade, G. Kridli, R. Shabadi, A. Imad

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

Defect-free joints were friction stir welded (FSW) from AZ31 Mg alloy sheets by employing optimum welding parameters for the tool geometry used. Microstructure, texture and mechanical response of the welded joints were studied to identify susceptibility of crack initiation in the different weld zones and to understand the overall fracture behavior of these welds. Uniaxial tensile testing conducted orthogonal to the welding direction at temperatures of 25, 100, 200, and 300. °C revealed that cracks initiated mainly on the tool's advancing side (AS) of the weld between thermo-mechanically affected zone (TMAZ) and stir zone (SZ). Such cracks were found to propagate preferentially along this interfacial region leading to complete fracture. This finding may be linked to the inhomogeneous plastic deformation in the weld resulting in strong texture and microhardness gradients at the interface region between the TMAZ (AS) and the SZ. On the other hand, in tensile samples machined along the welding direction and containing stir zone microstructure, second phase particles were identified as the preferred sites for cracks initiation.

Original languageEnglish
Pages (from-to)190-200
Number of pages11
JournalMaterials Science and Engineering A
Volume649
DOIs
Publication statusPublished - 1 Jan 2016

Keywords

  • Failure
  • Friction stir welding
  • Mechanical response
  • Micro-hardness
  • Microstructure characterization
  • Texture

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

Fingerprint Dive into the research topics of 'Microstructural observations and tensile fracture behavior of FSW twin roll cast AZ31 Mg sheets'. Together they form a unique fingerprint.

  • Cite this