With the popularization of friction stir welding (FSW), 5083-H321 and 6061-T6 aluminum alloy materials are widely used during the FSW process. In this study, the fatigue life of friction stir welding with two materials, i.e., 5083-H321 and 6061-T6 aluminum alloy, are studied. Fatigue tests were carried out on the base metal of these two materials as well as on the butt joints and overlapping FSW samples. The principle of the equivalent structural stress method is used to analyze the FSW test data of these two materials. The fatigue resistances of these two materials were compared and a unified principal S–N curve equation was fitted. Two key parameters of the unified principal S–N curve obtained by fitting, Cd is 4222.5, and h is 0.2693. A new method for an FSW fatigue life assessment was developed in this study and can be used to calculate the fatigue life of different welding forms with a single S–N curve. Two main fatigue tests of bending and tension were used to verify the unified principal S–N curve equation. The results show that the fatigue life calculated by the unified mean 50% master S–N curve parameters are the closest to the fatigue test results. The reliability, practicability, and generality of the master S–N curve fitting parameters were verified using the test data. The unified principal S–N curve acquired in this study can not only be used in aluminum alloy materials but can also be applied to other materials.
With the popularization of friction stir welding (FSW), 5083-H321 and 6061-T6 aluminum alloy materials are widely used during the FSW process. In this study, the fatigue life of friction stir welding with two materials, i.e., 5083-H321 and 6061-T6 aluminum alloy, are studied. Fatigue tests were carried out on the base metal of these two materials as well as on the butt joints and overlapping FSW samples. The principle of the equivalent structural stress method is used to analyze the FSW test data of these two materials. The fatigue resistances of these two materials were compared and a unified principal S–N curve equation was fitted. Two key parameters of the unified principal S–N curve obtained by fitting, Cd is 4222.5, and h is 0.2693. A new method for an FSW fatigue life assessment was developed in this study and can be used to calculate the fatigue life of different welding forms with a single S–N curve. Two main fatigue tests of bending and tension were used to verify the unified principal S–N curve equation. The results show that the fatigue life calculated by the unified mean 50% master S–N curve parameters are the closest to the fatigue test results. The reliability, practicability, and generality of the master S–N curve fitting parameters were verified using the test data. The unified principal S–N curve acquired in this study can not only be used in aluminum alloy materials but can also be applied to other materials.
[1] Ahmed B Mousa, Mousa Ahmed B, Abbass Muna K, et al. Fatigue behavior and fractography in friction stir welding zones of dissimilar aluminum alloys (AA5086-H32 with AA6061-T6). Materials Science and Engineering, 2020, 881(1): 1-15.
[2] A Chen, J Yang, X M Chen, et al. Fatigue property of friction stir welded butt joints for 6156-T6 aluminum alloy. Materials Science Forum, 2019, 960(1): 45-50.
[3] X Zhang, L X Wei, Y B Wang. Processing technology of aluminum alloy side wall of railway freight car. Metal Processing, 2016(31): 124-127.
[4] P M Kumar, K Balamurugan, S Gowthaman, et al. Fractography analysis and modeling studies on friction stir welded AA6061/SiC composite. Journal of Advanced Microscopy Research, 2018, 13(1): 72-78.
[5] Daria Zhemchuzhikova, Sergey Mironov, Rustam Kaibyshev. Fatigue performance of friction stir welded Al-Mg-Sc alloy. Metallurgical and Materials Transactions, 2019, 48(1): 150-158.
[6] E Salari, M Jahazi, A Khodabandeh, et al. Influence of tool geometry and rotational speed on mechanical properties and defect formation in friction stir lap welded 5456 aluminum alloy sheets. Mater and Design, 2014, 58(1): 381-389.
[7] M Ilangovan, S R Boopathy, Balasubramanian. Effect of tool pin profile on microstructure and tensile properties of friction stir welded dissimilar AA6061-AA5086 aluminium alloy joints. Defence Technology, 2015, 11(2): 174-184.
[8] R I Rodriguez, J B Jordon, P G Allison, et al. Microstructure and mechanical properties of dissimilar friction stir welding of 6061-to-7050 aluminum alloys. Mater and Design, 2015, 83(1): 60-65.
[9] L Giraud, H Robe, C Claudin, et al. Investigation into the dissimilar friction stir welding of AA7020-T651 and AA6060-T6. Journal of Materials Processing Technology, 2016, 235(1): 220-230.
[10] G Pouget, A P Reynolds. Residual stress and microstructure effects on fatigue crack growth in AA2050 friction stir welds. International Journal of Fatigue, 2008, 30(1): 463-472.
[11] Muna K Abbass, Sabah Kh Hussein, Ahmed A Khudair. Optimization of mechanical properties of friction stir spot welded joints for dissimilar aluminium alloys (AA2024-T3 and AA5754- H114). Arabian Journal for Science and Engineering, 2016, 41(11): 4563-4572.
[12] Muna K Abbass, Kareem M Raheef. Evaluation of the mechanical properties of friction stir. lap welded joints for dissimilar aluminum alloys(AA1100 To AA6061). 2018 1st International Scientific Conference of Engineering Sciences - 3rd Scientific Conference of Engineering Science (ISCES), IEEE, 2018: 192-197.
[13] Aghabeigi, Mahya, Hassanifard, et al. Evaluation of different strain-based damage criteria for predicting the fatigue life of friction stir spot-welded joints under multi-axial loading conditions. Journal of Materials Design and Application, 2020, 234(1): 156-166.
[14] L Sandnes, Y Grong, T Welo, et al. Fatigue properties of AA6060‐T6 butt welds made by hybrid metal extrusion & bonding. Fatigue & Fracture of Engineering Materials & Structures, 2020, 43(1): 1-9.
[15] M R M Aliha, Seyed Mohammad, Navid Ghoreishi, et al. Mechanical and fracture properties of aluminium cylinders manufactured by orbital friction stir welding. Fatigue & Fracture of Engineering Materials & Structures, 2020, 43(1): 9-12.
[16] S Suresh, K Venkatesan, E Natarajan, et al. Evaluating weld properties of conventional and swept friction stir spot welded 6061-T6 aluminium alloy. Materials Express, 2019, 9(8): 851-860.
[17] E T Abioye, H Zuhailawati, S A Anasyida, et al. Investigation of the microstructure mechanical and wear properties of AA6061-T6 friction stir weldments with different particulate reinforcements addition - ScienceDirect. Journal of Materials Research and Technology, 2019, 8(5): 3917-3928.
[18] AMBS Antunes, CARP Baptista, MJR Barboza, et al. Effect of the interrupted aging heat treatment T6I4 on the tensile properties and fatigue resistance of AA7050 alloy. Journal of the Brazilian Society of Mechanical Sciences and Engineering, 2019, 41(8): 1-8.
[19] T S Kumar, A Nagesha, R Kannan. Thermal cycling effects on the creep-fatigue interaction in type 316LN austenitic stainless steel weld joint. International Journal of Pressure Vessels and Piping, 2019, 178: 104-109.
[20] Niu Kun. Microstructure and properties of friction stir welded joints of aluminum alloy and magnesium alloy heterogeneous materials. Changchun: Jilin University, 2012.
[21] R Pan. Effect of material properties on weld formation and mechanical properties of friction stir welding of aluminum alloy. Nanchang: Nanchang Aeronautical University, 2015.
[22] H Y Wang, W J Qi, D Nong. Microstructure and properties of friction stir weldindg 6061 aluminium alloy joint. Chinese Journal of Rare Metals, 2015, 35(5): 638-642.
[23] P Dong, J K Hong, D A Osage, et al. Master S-N curve method for fatigue evaluation of welded components. Welding Research Council Bulletin, 2002(474): 1-44.
[24] P Dong. Length scale of secondary stresses in fracture and fatigue. International Journal of Pressure Vessels and Piping, 2007, 85(3): 128-143.
[25] Z J Lv, H Zhang, Y Guo. Processes and properties of friction stir welding joint of 6061 Al-alloy with zero title angle. Journal of Netshape Forming Engineering, 2018, 10(4): 108-113.
[26] H S Qin, X Q Yang. Performances of fatigue crack growth for aluminum friction stir welds and base materials. Journal of Aeronautical Materials, 2017, 37(5): 41-47.
[27] The International Organization for Standardization. Metallic materials fatigue testing axial force control method. Switzerland: Technical Committee ISO/TC, 2006.
[28] ASME. Ⅷ DIV 2-2007 ASME boiler and pressure vessel code. New York: The American Society of Mechanical Engineers, 2007.
[29] W Z Zhao, H L Wei, J Fang. The theory and application of the virtual fatigue test of welded structures based on the master S-N curve method. Transactions of the China Welding Institution, 2014, 35(5): 75-78.
[30] Peng Mi, Ruijie Wang, Qinghe Yang. Study on kissing bond depth on the fatigue strength of AA5083 FSW butt joints. Mechanical Science Technology for Acrospace Engineering, 2020, 4: 1-7.
[31] Baohai Zhang. Study on the microstructure and mechanical properties of bobbin tool friction stir welding of 6082-T6 aluminum alloy. Jinan: Shandong University, 2017. (in Chinese)
[32] Rongkang Chen, Chunfang Sun, Ying Dai. Fatigue property of friction stir welded extruded aluminium alloy 6005A. Chinese Quarterly Mechanics, 2012. (in Chinese)
[33] Qingfeng Wang. Friction stir welding of 6005A-T6 aluminum alloy for the metro vehicles car body. Hangzhou: Zhejiang University of Technology, 2015. (in Chinese)
