scholarly journals Improving Fatigue Performance of Laser-Welded 2024-T3 Aluminum Alloy Using Dry Laser Peening

Metals ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 1192 ◽  
Author(s):  
Sano ◽  
Eimura ◽  
Hirose ◽  
Kawahito ◽  
Katayama ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Weld Metal ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Fatigue Performance ◽  
Laser Peening ◽  
Residual Tensile Stress ◽  
Atmospheric Conditions ◽  
2024 Aluminum Alloy ◽  
Welding Defects

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.

Fatigue Performance of Laser Peened 7050-T7451 Aluminum Alloy

2006 ◽  
Author(s):  
Adrian T. DeWald ◽  
Harold Luong ◽  
John E. VanDalen ◽  
Michael R. Hill
Keyword(s):  
Residual Stress ◽  
Aluminum Alloy ◽  
Fatigue Testing ◽  
Fatigue Performance ◽  
Laser Peening ◽  
Metallic Materials ◽  
Stress Distributions ◽  
Life Data ◽  
Slitting Method ◽  
Life Improvement

Laser peening is an emerging technology for the surface treatment of metallic materials that is capable of enhancing resistance to fatigue failure. This paper presents results quantifying the effects of laser peening on residual stress and fatigue performance of samples machined from 7050-T7451 aluminum alloy. Residual stress distributions were measured for treatment with different laser peening parameter sets using the slitting method. For particular laser peening parameter sets, stress versus life data were generated over a range of applied loads and compared with as-machined and shot peened results. Two different sample types were used for fatigue testing: smooth bend bars and notched bend bars. In general, laser peening produced a fatigue life improvement of approximately 3 to 6 relative to as machined samples and 1.5 to 2 relative to shot peened samples over the range of stress levels tested.

Effect of Temperature on Surface Mechanical Property of 2024 Aluminum Alloy Treated by Laser Peening

2016 ◽  
Vol 43 (10) ◽  
pp. 1002003
Author(s):  
孟宪凯 Meng Xiankai ◽  
周建忠 Zhou Jianzhong ◽  
苏纯 Su Chun ◽  
黄舒 Huang Shu ◽  
盛杰 Sheng Jie ◽  
...  
Keyword(s):  
Mechanical Property ◽  
Aluminum Alloy ◽  
Effect Of Temperature ◽  
Laser Peening ◽  
2024 Aluminum Alloy

scholarly journals Effects of Laser Peening with a Pulse Energy of 1.7 mJ on the Residual Stress and Fatigue Properties of A7075 Aluminum Alloy

Metals ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 1716
Author(s):  
Yuji Sano ◽  
Kiyotaka Masaki ◽  
Yoshio Mizuta ◽  
Satoshi Tamaki ◽  
Tomonao Hosokai ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Pulse Energy ◽  
Laser Pulses ◽  
Microchip Laser ◽  
Fatigue Properties ◽  
Laser Peening ◽  
Robot Arm ◽  
X Ray Diffraction ◽  
Bending Fatigue ◽  
Laser Peening Without Coating

Laser peening without coating (LPwC) using a palmtop-sized microchip laser has improved the residual stresses (RSs) and fatigue properties of A7075 aluminum alloy. Laser pulses with a wavelength of 1.06 μm and duration of 1.3 ns from a Q-switched Nd:YAG microchip laser were focused onto A7075 aluminum alloy samples covered with water. X-ray diffraction revealed compressive RSs on the surface after irradiation using laser pulses with an energy of 1.7 mJ, spot diameter of 0.3 mm, and density of 100–1600 pulse/mm2. The effects were evident to depths of a few hundred micrometers and the maximum compressive RS was close to the yield strength. Rotation-bending fatigue experiments revealed that LPwC with a pulse energy of 1.7 mJ significantly prolonged the fatigue life and increased the fatigue strength by about 100 MPa with 107 fatigue cycles. The microchip laser used in this study is small enough to fit in the hand or be mounted on a robot arm. The results may lead to the development of tools that extend the service life of various metal parts and structures, especially outdoors where conventional lasers are difficult to apply.

scholarly journals Numerical Investigation on the Influence of Water Vapor Ionization on the Dynamic and Energy Deposition of Femtosecond Ultraviolet Laser Filamentation in Air

2019 ◽  
Vol 9 (20) ◽  
pp. 4201
Author(s):  
Qingwei Zeng ◽  
Lei Liu ◽  
Kejin Zhang ◽  
Shuai Hu ◽  
Taichang Gao ◽  
...  
Keyword(s):  
Water Vapor ◽  
Energy Deposition ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Nonlinear Propagation ◽  
High Humidity ◽  
Atmospheric Conditions ◽  
Energy Increase ◽  
Influence Of Water ◽  
Vapor Ionization

The effects of water vapor ionization on the nonlinear propagation of femtosecond laser pulses with a 248 nm wavelength are numerically investigated in this paper. It is found that ionization of H2O molecules plays a significant role in air ionization, which seriously affects the dynamic and energy deposition of filamentation. The propagation of femtosecond pulses in air with different humidity levels are compared. The total number of electrons and total deposited pulse energy increase with the humidity increases. However, they tend to be saturated in high humidity conditions. Results presented here are conducive to characterizing the long-range propagation of filaments under atmospheric conditions.

scholarly journals High energy femtosecond laser peening of 2024 aluminum alloy

Procedia CIRP ◽  
2018 ◽  
Vol 74 ◽  
pp. 357-361 ◽  
Author(s):  
Shuting Lei ◽  
Guang Yang ◽  
Xinya Wang ◽  
Shouyuan Chen ◽  
Amy Prieb ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Femtosecond Laser ◽  
High Energy ◽  
Laser Peening ◽  
2024 Aluminum Alloy

Inorganic-organic Hybrid Materials for Real 3-D Sub-νm Lithography

2003 ◽  
Vol 780 ◽  
Author(s):  
R. Houbertz ◽  
J. Schulz ◽  
L. Fröhlich ◽  
G. Domann ◽  
M. Popall ◽  
...  
Keyword(s):  
Femtosecond Laser ◽  
Sol Gel ◽  
Laser Pulses ◽  
Femtosecond Laser Pulses ◽  
Hybrid Polymer ◽  
Organic Hybrid ◽  
Two Photon ◽  
Applied Technology ◽  
Scale Structures ◽  
Sol Gel Synthesis

AbstractReal 3-D sub-νm lithography was performed with two-photon polymerization (2PP) using inorganic-organic hybrid polymer (ORMOCER®) resins. The hybrid polymers were synthesized by hydrolysis/polycondensation reactions (modified sol-gel synthesis) which allows one to tailor their material properties towards the respective applications, i.e., dielectrics, optics or passivation. Due to their photosensitive organic functionalities, ORMOCER®s can be patterned by conventional photo-lithography as well as by femtosecond laser pulses at 780 nm. This results in polymerized (solid) structures where the non-polymerized parts can be removed by conventional developers.ORMOCER® structures as small as 200 nm or even below were generated by 2PP of the resins using femtosecond laser pulses. It is demonstrated that ORMOCER®s have the potential to be used in components or devices built up by nm-scale structures such as, e.g., photonic crystals. Aspects of the materials in conjunction to the applied technology are discussed.

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