Fatigue behaviour of dissimilar friction stir spot welds between A6061‐T6 and low carbon steel sheets welded by a scroll grooved tool without probe |
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| Authors: | Y UEMATSU K TOKAJI Y TOZAKI Y NAKASHIMA T SHIMIZU |
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| Affiliation: | 1. Department of Mechanical and Systems Engineering, Gifu University, 1‐1 Yanagido, Gifu 501‐1193, Japan;2. Gifu Prefectural Research Institute for Machinery and Material, 1288 Oze, Seki 501‐3265, Japan;3. ADVICS Co. Ltd., 2‐1 Showa‐cho, Kariya, Aichi 448‐8688, Japan;4. Department of Mechanical Engineering, Toyota National College of Technology, 2‐1 Eisei‐cho, Toyota 471‐8525, Japan |
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| Abstract: | A6061 and low carbon steel sheets, whose thicknesses were 2 mm, were welded by a friction stir spot welding (FSSW) technique using a scroll grooved tool without probe (scroll tool). Tensile‐shear fatigue tests were performed using lap‐shear specimens at a stress ratio R = 0.1, and the fatigue behaviour of dissimilar welds was discussed. Tensile‐shear force of the dissimilar welds was higher than that of the A6061 similar ones. Furthermore, the dissimilar welds exhibited nearly the same fatigue strengths as the A6061 similar ones, indicating FSSW by a scroll tool was effective technique for joining aluminium to steel sheet. Fatigue fracture modes of the dissimilar welds were dependent on load levels, where shear fracture through the interface between A6061 and steel occurred at high load levels, while crack grew through A6061 sheet at low load level. |
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| Keywords: | crack growth dissimilar weld fatigue strength fracture mechanism friction stir spot welding |
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