Microstructure and Mechanical Properties of Dissimilar Friction Stir Welding between Ultrafine Grained 1050 and 6061-T6 Aluminum Alloys
1
Joining and Welding Research Institute, Osaka University, Ibaraki 5670047, Japan
2
Department of Materials Science and Engineering, Kyoto University, Kyoto 6068501, Japan
*
Author to whom correspondence should be addressed.
Academic Editor: Giuseppe Casalino
Metals 2016, 6(10), 249; https://doi.org/10.3390/met6100249
Received: 25 August 2016 / Revised: 12 October 2016 / Accepted: 15 October 2016 / Published: 21 October 2016
(This article belongs to the Special Issue Advances in Welding Metal Alloys, Dissimilar Metals and Additively Manufactured Parts)
Abstract
The ultrafine grained (UFGed) 1050 Al plates with a thickness of 2 mm, which were produced by the accumulative roll bonding technique after five cycles, were friction stir butt welded to 2 mm thick 6061-T6 Al alloy plates at a different revolutionary pitch that varied from 0.5 to 1.25 mm/rev. In the stir zone, the initial nano-sized lamellar structure of the UFGed 1050 Al alloy plate transformed into an equiaxial grain structure with a larger average grain size due to the dynamic recrystallization and subsequent grain growth. However, an equiaxial grain structure with a much smaller grain size was simultaneously formed in the 6061 Al alloy plates, together with coarsening of the precipitates. Tensile tests of the welds obtained at different welding speeds revealed that two kinds of fracture modes occurred for the specimens depending on their revolutionary pitches. The maximum tensile strength was about 110 MPa and the fractures were all located in the stir zone close to the 1050 Al side. View Full-TextKeywords:
ultrafine grained structure; dissimilar friction stir welding; dynamic recrystallization; aluminum alloy
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MDPI and ACS Style
Sun, Y.; Tsuji, N.; Fujii, H. Microstructure and Mechanical Properties of Dissimilar Friction Stir Welding between Ultrafine Grained 1050 and 6061-T6 Aluminum Alloys. Metals 2016, 6, 249.
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