Effects of Post-weld Aging Treatment on Friction Stir Welding Joint of 6082-T6 Aluminum Alloy
WANG Xijing, WEI Xueling, ZHANG Liangliang
State Key Laboratory of Gansu Advanced Nonferrous Metal Materials, School of Materials Science and Engineering, Lanzhou University of Technology, Lanzhou 730050
Abstract: Microstructure evolution and mechanical properties of friction stir welded 6082-T6 aluminum alloy during post-weld natural and artificial aging treatment were investigated by means of transmission electron microscope(TEM), scanning electron microscope (SEM), tensile test machine and Vickers hardness tester. The results show that microhardness of the joint after artificial aging treatment was about 10-25HV higher than welded and naturally aged alloy. Artificial aging was superior to natural aging on improving the microhardness of the nugget zone and heat affected zone. After post-weld natural aging or artificial aging treatment, the mechanical properties of welded joint was improved to certain extents.The tensile strength increased by 12% and elongation decreased by 9% after artificial aging, compared to natural aging. Artificial aging was more effective for tensile strength improvement. After artificial aging, the microstructure of the nugget had significant changes. NZ was mainly GP zone and the microhardness increased with the increase of the cluster size and the GP region after artificial aging treatment. HAZ was mainly coarse β′, but microhardness had little change after artificial aging treatment.It is found that the shape of precipitates can be determined by the interface energy and strain energy via microstructure analysis.
1 Miller W C, Zhuang L, Bottema J, et al. Recent development in aluminum alloys for the automotive industry[J]. Mater Sci Eng A,2000,280:37. 2 Li X L, Chen J X, Liu C H, et al. Effects of T6 and T78 tempers on the microstructures and properties of Al-Mg-Si-Cu alloys[J]. Acta Metall Sin,2013,49(2):243(in Chinese). 李祥亮, 陈江华, 刘春辉,等. T6和T78时效工艺对Al-Mg-Si-Cu合金显微结构和性能的影响[J]. 金属学报,2013,49(2):243. 3 Feng J N,Chen J H,Liu C H,et al. Effects of pre-aging treatments on the microstructures and properties before and after paint bake cycle for a 6016 aluminum alloy[J]. J Chin Elec Microsc Soc,2012,31(6):461(in Chinese). 冯佳妮, 陈江华, 刘春辉,等. 预时效对6016铝合金烤漆前后组织和性能的影响[J]. 电子显微学报,2012,31(6):461. 4 Mishra R S, Ma Z Y. Friction stir welding and processing[J]. Mater Sci Eng R,2005,50(1):1. 5 Liu W. Study on the production process of 6082 aluminium alloy profiles for ship[J]. Alum Fabr,2001,24(3):19(in Chinese). 刘炜. 6082铝合金船用铝型材的生产工艺研究[J].铝加工,2001,24(3):19. 6 Elangovan K, Balasubramanian V. Influences of post-weld heat treatment on tensile properties of friction stir-welded AA6061 aluminum alloy joints[J]. Mater Charact,2008,59(9):1168. 7 Wang Y R, Huang W R, et al. Effects of post weld heat treatment on microstructure and mechanical properties of 2A14 high strength aluminum alloy by electron beam welding[J]. Chin J Mech Eng,2011,47(20):141(in Chinese). 王亚荣, 黄文荣,等. 焊后热处理对 2A14 高强铝合金电子束焊接头组织及力学性能的影响[J]. 机械工程学报,2010,47(20):141. 8 Tsao C S, Chen C Y, Jeng U S, et al. Precipitation kinetics and transformation of metastable phases in Al-Mg-Si alloys[J]. Acta Mater,2006,54(17):4621 9 Zandbergen H W, Andersen S J, Jansen J. Structure determination of Mg5Si6 particles in Al by dynamic electron diffraction studies[J]. Science,1997,277(5330):1221. 10 Yang W C, Wang M P, Sheng X F, et al. Study of the aging precipitation and hardening behavior of 6005A alloy sheet for rail traffic vehicle[J]. Acta Metall Sin,2010,46(12):1481(in Chinese). 杨文超, 汪明朴, 盛晓菲,等.轨道交通车辆用6005A合金板材时效析出及硬化行为研究[J].金属学报,2010,46(12):1481. 11 Mrówka-Nowotnik G, Sieniawski J, Nowotnik A. Tensile properties and fracture toughness of heat treated 6082 alloy[J]. J Achi Mater Manuf Eng,2006,17(1):105. 12 Sang Y. The hardening behaviors and precipitation in the Al-Mg-Si alloys during multi-step aging[D]. Changsha:Hunan University,2006(in Chinese). 桑益.Al-Mg-Si合金的多级时效硬化特性和析出行为[D].长沙:湖南大学,2012. 13 Chen K H, Liu Y Z, Liu H W, et al. Microstructure and mechanical properties of enhanced solution treated 7075 and 2024 aluminum alloys[J]. Chin J Nonferrous Met,2000,10(6):819(in Chinese). 陈康华, 刘允中, 刘红卫.7075和2024铝和金的固溶组织与力学性能[J]. 中国有色金属学报,2000,10(6):819.
渝公网安备50019002502923号 版权所有：《材料导报》编辑部
2017, Vol. 31 
