Browse > Article
http://dx.doi.org/10.5762/KAIS.2017.18.5.278

Evaluation of Mechanical Properties of AZ61 Magnesium Alloy Joints at various Welding Speeds  

Sun, Seung-Ju (Advanced Materials Research Team, Korea Railroad Research Institute)
Kim, Jung-Seok (Advanced Materials Research Team, Korea Railroad Research Institute)
Lee, Woo-Geun (Advanced Materials Research Team, Korea Railroad Research Institute)
Lim, Jae-Yong (School of Mechanical Engineering, Daegu University)
Publication Information
Journal of the Korea Academia-Industrial cooperation Society / v.18, no.5, 2017 , pp. 278-284 More about this Journal
Abstract
In this study, the heat input conditions suitable for the AZ61 magnesium alloy were derived by controlling the welding speed at a constant rotational speed. In addition, from an economic point of view, industry demands higher welding speeds. Therefore,the effects of the welding speed were studied. The rotational speed applied was 800rpm, and the welding speed was varied from 100 to 500mm/min to evaluate the behavior of the welded regions. Tensile and hardness tests were conducted to examine the mechanical properties. Optical microscopy was used to observe the microstructure and soundness of the welded regions. Defects were observed at the welded region when the welding speed was more than400mm/min. As the welding speed increased, the grain size of the stir zone decreased and the hardness tended to increase proportionally. When the rotational speed was 800 rpm and the welding speed was 200mm/min and 300mm/min, there wereno defects in the welded region and excellent mechanical properties were recorded. In addition, the joint efficiencies were 100.5% and 101.2%, respectively, and the ultimate tensile strength was similar to that of the base metal. Fracture of the tensile specimen occurred between the advancing side and stir zone, and the fracture location coincided with the region where the hardness decreased temporarily.
Keywords
Friction Stir Welding; Hardness; Magnesium Alloys; Microstructure; Tensile test;
Citations & Related Records
Times Cited By KSCI : 1  (Citation Analysis)
연도 인용수 순위
1 D. H. Jang, 'Process Development for Automotive Hybrid Hood using Magnesium Alloy AZ31B Sheet', Transactions of Materials Processing, vol. 20, no. 2, pp. 160-166, 2011. DOI: https://doi.org/10.5228/KSTP.2011.20.2.160   DOI
2 H. B. Chen, K. Yan, T. Lin, S. B. Chen, C. Y. Jiang, Y. Zhao, "The investigation of typical welding defects for 5456 aluminum alloy friction stir welds", Materials Science and Engineering: A, vol. 433, no. 1, pp. 64-69, 2006. DOI: https://doi.org/10.1016/j.msea.2006.06.056   DOI
3 R. S. Mishra, Z. Y. Ma, "Friction stir welding and processing", Materials Science and Engineering: R: Reports, vol. 50, no. 1, pp. 1-78, 2005. DOI: https://doi.org/10.1016/j.mser.2005.07.001   DOI
4 O. Frigaard, O. Grong, B. Bjorneklett, OT. Midling, In Proceedings of the 1st international symposium on friction stir welding, Thousand Oaks, CA, USA; 14-16 June, 1999.
5 M. S. Moghaddam,, R. Parvizi, M. Haddad- Sabzevar, A. Davoodi, "Microstructural and mechanical properties of friction stir welded Cu-30Zn brass alloy at various feed speeds: Influence of stir bands", Materials & Design, vol. 32, no. 5, pp. 2749-2755, 2011. DOI: https://doi.org/10.1016/j.matdes.2011.01.015   DOI
6 Z. W. Chen, T. Pasang, Y. Qi, "Shear flow and formation of Nugget zone during friction stir welding of aluminium alloy 5083-O", Materials Science and Engineering: A, vol. 474, no. 1, pp. 312-316, 2008. DOI: https://doi.org/10.1016/j.msea.2007.05.074   DOI
7 N. Afrin, D. L. Chen, X. Cao, M. Jahazi, "Microstructure and tensile properties of friction stir welded AZ31B magnesium alloy", Materials Science and Engineering: A, 472(1), 179-186, 2008. DOI: https://doi.org/10.1016/j.msea.2007.03.018   DOI
8 Y. G. Kim, H. Fujii, T. Tsumura, T. Komazaki, K. Nakata, "Three defect types in friction stir welding of aluminum die casting alloy", Materials Science and Engineering: A, vol. 415, no. 1, pp. 250-254, 2006. DOI: https://doi.org/10.1016/j.msea.2005.09.072   DOI
9 G. M. Xie, Z. Y. Ma, L. Geng, "Development of a fine-grained microstructure and the properties of a nugget zone in friction stir welded pure copper", Scripta Materialia, vol. 57, no. 2, pp. 73-76, 2007. DOI: https://doi.org/10.1016/j.scriptamat.2007.03.048   DOI
10 Y. B. Tan, X. M. Wang, M. Ma, J. X. Zhang, W. C. Liu, R. D. Fu S. Xiang, "A study on microstructure and mechanical properties of AA 3003 aluminum alloy joints by underwater friction stir welding", Materials Characterization, vol. 127, pp. 41-52, 2017. DOI: https://doi.org/10.1016/j.matchar.2017.01.039   DOI
11 G. M. Xie, Z. Y. Ma, L. Geng, "Development of a fine-grained microstructure and the properties of a nugget zone in friction stir welded pure copper", Scripta Materialia, vol. 57, no. 2, pp. 73-76, 2007. DOI: https://doi.org/10.1016/j.scriptamat.2007.03.048   DOI
12 T. Hirata, T. Oguri, H. Hagino, T. Tanaka, S. W. Chung, Y. Takigawa, K. Higashi, "Influence of friction stir welding parameters on grain size and formability in 5083 aluminum alloy," Materials Science and Engineering: A, vol. 456, no. 1, pp.344-349, 2007. DOI: https://doi.org/10.1016/j.msea.2006.12.079   DOI
13 J. Yang, D. Wang, B. L. Xiao, D. R. Ni, Z. Y. Ma, "Effects of rotation rates on microstructure, mechanical properties, and fracture behavior of friction stir-welded (FSW) AZ31 magnesium alloy", Metallurgical and Materials Transactions A, vol. 44, no. 1, pp. 517-530, 2013. DOI: https://doi.org/10.1007/s11661-012-1373-4   DOI
14 S. H. C. Park, Y. S. Sato, H. Kokawa, "Microstructural evolution and its effect on Hall-Petch relationship in friction stir welding of thixomolded Mg alloy AZ91D," Journal of materials science, vol. 38, no. 21, pp. 4379-4383, 2003. DOI: https://doi.org/10.1023/A:1026351619636   DOI
15 S. H. C. Park, Y. S. Sato, H. Kokawa, "Effect of micro-texture on fracture location in friction stir weld of Mg alloy AZ61 during tensile test", Scripta Materialia, vol. 49, no. 2, pp. 161-166, 2003. DOI: https://doi.org/10.1016/S1359-6462(03)00210-0   DOI
16 E. O. Hall, "The deformation and ageing of mild steel: III discussion of results", Proceedings of the Physical Society Section B, vol. 64, no. 9, pp. 747, 1951. DOI: https://doi.org/10.1088/0370-1301/64/9/303   DOI
17 N. J. Petch, "The cleavage strength of polycrystals", The Journal of the Iron and Steel Institute, vol. 174, pp. 25-28, 1953.
18 H. J. Liu, H. Fujii, M. Maeda, K. Nogi, "Tensile properties and fracture locations of friction-stir- welded joints of 2017-T351 aluminum alloy", Journal of Materials Processing Technology, vol. 142, no. 3, pp. 692-696, 2003. DOI: https://doi.org/10.1016/S0924-0136(03)00806-9   DOI
19 W. Woo, H. Choo, D. W. Brown, P. K. Liaw, Z. Feng, "Texture variation and its influence on the tensile behavior of a friction-stir processed magnesium alloy", Scripta materialia, vol. 54, no. 11, pp. 1859-1864, 2006. DOI: https://doi.org/10.1016/j.scriptamat.2006.02.019   DOI