Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7171684 | International Journal of Fatigue | 2016 | 10 Pages |
Abstract
The fatigue behavior of laser hybrid welded 7000 series aluminum alloys with high Zn was investigated by electron backscattered diffraction, transmission electron microscopy, energy-dispersive spectroscopy, basic mechanical tests, fatigue cracking rate, synchrotron radiation X-ray computed micro-tomography, high-cycle fatigue and residual stress-based fatigue crack growth simulation. The results show that hybrid laser welding process leads to essential changes of microstructure and micro-hardness. It has also been found that the fatigue performance of grinded laser shock treated joints is significantly improved compared with that of as-received welded joints. Besides, hybrid laser welded joints present slightly higher fatigue crack propagation rate than base metal under load ratios of RÂ =Â 0.1 and 0.3, which can be intrinsically attributed to the higher crackability of weld and inner porosity in terms of grain disorientation and three-dimensional gas pores. Based on finite element modeling, a new fatigue crack propagation life model is established by incorporating weld residual stress, and the predictions are in good agreement with experimental results under different welding parameters.
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Authors
S.C. Wu, Y.N. Hu, H. Duan, C. Yu, H.S. Jiao,