Improving Fatigue Performance of Laser-Welded 2024-T3 Aluminum Alloy Using Dry Laser Peening
by
Tomokazu Sano 1,*, Takayuki Eimura 1, Akio Hirose 1, Yosuke Kawahito 2, Seiji Katayama 2, Kazuto Arakawa 3, Kiyotaka Masaki 4, Ayumi Shiro 5, Takahisa Shobu 6 and Yuji Sano 7,8
Tomokazu Sano 1,*, Takayuki Eimura 1, Akio Hirose 1, Yosuke Kawahito 2, Seiji Katayama 2, Kazuto Arakawa 3, Kiyotaka Masaki 4, Ayumi Shiro 5, Takahisa Shobu 6 and Yuji Sano 7,8
1
Division of Materials and Manufacturing Science, Graduate School of Engineering, Osaka University, 2-1 Yamada-oka, Suita 565-0871, Japan
2
Joining and Welding Research Institute, Osaka University, 11-1 Mihogaoka, Ibaraki 567-0047, Japan
3
Interdisciplinary Faculty of Science and Engineering, Shimane University, 1060 Nishikawatsu-cho, Matsue 690-8504, Japan
4
National Institute of Technology, Okinawa College, 905 Henoko, Nago 905-2192, Japan
5
Quantum Beam Science Research Directorate, National Institute for Quantum and Radiological Science and Technology, Kouto, Sayo 679-5148, Japan
6
Materials Sciences Research Center, Japan Atomic Energy Agency, Kouto, Sayo 679-5148, Japan
7
Division of Research Innovation and Collaboration, Institute for Molecular Science, National Institutes of Natural Sciences, 38 Nishigo-Naka, Myodaiji, Okazaki 444-8585, Japan
8
Department of Quantum Beam Physics, Institute of Scientific and Industrial Research, Osaka University, 8-1 Mihogaoka 567-0047, Japan
*
Author to whom correspondence should be addressed.
Metals 2019, 9(11), 1192; https://doi.org/10.3390/met9111192
Received: 23 September 2019 / Revised: 30 October 2019 / Accepted: 4 November 2019 / Published: 6 November 2019
(This article belongs to the Special Issue Laser Shock Processing and Related Phenomena)
The purpose of the present study was to verify the effectiveness of dry laser peening (DryLP), which is the peening technique without a sacrificial overlay under atmospheric conditions using femtosecond laser pulses on the mechanical properties such as hardness, residual stress, and fatigue performance of laser-welded 2024 aluminum alloy containing welding defects such as undercuts and blowholes. After DryLP treatment of the laser-welded 2024 aluminum alloy, the softened weld metal recovered to the original hardness of base metal, while residual tensile stress in the weld metal and heat-affected zone changed to compressive stresses. As a result, DryLP treatment improved the fatigue performances of welded specimens with and without the weld reinforcement almost equally. The fatigue life almost doubled at a stress amplitude of 180 MPa and increased by a factor of more than 50 at 120 MPa. DryLP was found to be more effective for improving the fatigue performance of laser-welded aluminum specimens with welding defects at lower stress amplitudes, as stress concentration at the defects did not significantly influence the fatigue performance.
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited
MDPI and ACS Style
Sano, T.; Eimura, T.; Hirose, A.; Kawahito, Y.; Katayama, S.; Arakawa, K.; Masaki, K.; Shiro, A.; Shobu, T.; Sano, Y. Improving Fatigue Performance of Laser-Welded 2024-T3 Aluminum Alloy Using Dry Laser Peening. Metals 2019, 9, 1192.
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