Investigation of Microstructures and Fatigue Properties of Friction Stir Welded Al-Mg Alloy

Abstract

FS welds have a sound joint for the lack of voids, cracks and distortions. When compared to the base material, friction stir welding (FSW) joints exhibit a finer crystal grain in the weld nugget, and advancing side has a clearer boundary with the weld nugget than that of the retreating side. The fatigue life of FS welds is 6-14 times longer than that of MIG-pulse welds under the stress ratio R = 0.1 and the calculated fatigue characteristic values of each weld increase from 42.32 MPa for MIG to 68.47 MPa for FSW at 2 x 106 cycles. In the high-cycle regime, the fatigue strength of the FSW joint is almost equivalent to that of the base material. The fatigue fracture of FSW revealed regions of crack initiation, stable crack growth and overload.

Department(s)

Materials Science and Engineering

Keywords and Phrases

Al-Mg Alloy; Friction Stir Welding; MIG-Pulse Welding; Crack Propagation; Fatigue Of Materials; Fracture; Microstructure; Welding; Aluminum Alloys

International Standard Serial Number (ISSN)

0254-0584

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2006 Elsevier BV, All rights reserved.

Publication Date

01 Aug 2006

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