Laser shock processing with two different laser sources on 2050‐T8 aluminum alloy

Peyre, P.; Hfaiedh, Neïla; Song, Hongbin; Ji, Vincent; Vignal, V.; Seiler, Wilfrid; Branly, S.

doi:10.1108/17579861111108644

Cited by 16 publications

(13 citation statements)

References 7 publications

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“…Differences between the magnitude of the residual stress after LSP in the x-direction (s x ) and in the y-direction (s y ) in the surface region are found in multitude of Refs. [12][13][14][15], but until now the explanation for this residual stress anisotropy has been an open question [8]. Trdan et al [16] (in which residual stress evaluation also confirmed beneficial compressive residual stresses after LSPwC, with higher compressive residual stress in the advancing LSPwC) studied the LSPwC effects on the dislocation generation, dislocation transition and grain refinement through-depth distribution, which could be related to the residual stress anisotropy.…”

Section: Introductionmentioning

confidence: 94%

“…[13]) as a quasi-Gaussian function: P(x,y,t)¼P(t)exp[À 0.85(x 2 þy 2 )/R 2 ], where x and y are the surface coordinates and R is the pulse radius. In addition, when simulating a large number of LSPwC pulses applied at different locations and times, a minimum time interval between successive impacts had to be selected to ensure a quasi-residual stress field (shock and relaxation).…”

Section: Shock Wave Modeling: Evolution and Spatial Distributionmentioning

confidence: 99%

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Random-type scanning patterns in laser shock peening without absorbing coating in 2024-T351 Al alloy: A solution to reduce residual stress anisotropy

Correa

Peral

Porro

et al. 2015

Optics & Laser Technology

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Section: Introductionmentioning

confidence: 94%

Section: Shock Wave Modeling: Evolution and Spatial Distributionmentioning

confidence: 99%

Random-type scanning patterns in laser shock peening without absorbing coating in 2024-T351 Al alloy: A solution to reduce residual stress anisotropy

Correa

Peral

Porro

et al. 2015

Optics & Laser Technology

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“…Considering Eqs (7), (9) and (11) in Eq. (12), the residual fatigue life for damaged specimen can be calculated by…”

Section: Dissipated Energy Enhancement Mechanismmentioning

confidence: 99%

“…found that the increase in hardness is slightly because of hardening effects and can be mainly attributed to the presence of compressive residual stresses. Peyre et al . treated a 2050‐T8 aluminium alloy by two different lasers (3 and 1.5 J output energies) and found that similar surface deformations and work‐hardening levels were observed.…”

Section: Introductionmentioning

confidence: 96%

“…Cellard et al 10 found that the increase in hardness is slightly because of hardening effects and can be mainly attributed to the presence of compressive residual stresses. Peyre et al 11 treated a 2050-T8 aluminium alloy by two different lasers (3 and 1.5 J output energies) and found that similar surface deformations and work-hardening levels were observed. Rodopoulos et al 12 investigated that LSP, controlled shot peening and dual treatments were expected to increase the fatigue life of poorly machined components and thus to reduce the production cost, and LSP was found to cause negligible strain hardening in the case of controlled shot peening and dual treatment.…”

mentioning

confidence: 96%

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Residual life prediction for healing fatigue damaged copper film by laser shock peening

Liu

Shang

Zhang

et al. 2013

Fatigue Fract Eng Mat Struct

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A B S T R A C T A healing method for fatigue damage was studied by laser shock peening (LSP) with excimer laser for polycrystalline copper film. It is found that work hardening due to LSP could be responsible for the improvement of residual fatigue lives for the damaged and undamaged specimens by LSP, and the hardening degree for the damaged specimen by LSP is obviously higher than that for the undamaged specimen by LSP. In this paper, two basic mechanisms were identified. One is the dissipated energy enhancement mechanism, which improves the fatigue life caused by laser shock stress, and the other is the healing mechanism, which leads to a further improvement. Based on the two mechanisms, a residual fatigue life prediction method is proposed by the view of energy consumption before and after LSP. The predicted lives by the proposed method agree well with the experimental results.Keywords laser shock peening; work hardening; dissipated energy enhancement mechanism; healing mechanism; life prediction.coefficient for the original specimen by LSP k D ¼ hardening coefficient for the damaged specimen by LSP m ¼ modified exponent of hardening degree N 0 ¼ fatigue life for original specimen N D ¼ consumed life of the damaged specimen N DEEM ¼ improved fatigue life caused by the extra plastic strain energy for the original specimen by LSP N D DEEM ¼ improved fatigue life caused by the extra plastic strain energy for the damaged specimen by LSP N LSP D¼0 ¼ fatigue life for the original specimen by LSP N HM ¼ pure healing life caused by HM N r ¼ residual life of the damaged specimen by LSP n′ ¼ cyclic hardening exponent of the material ΔW p0 ¼ plastic strain energy for the original specimen without LSP ΔW LSP;D p ¼ plastic strain energy for the damaged specimen with LSP ΔW LSP;D¼0 p ¼ plastic strain energy for the original specimen with LSP Δσ ¼ stress range Δε p ¼ plastic strain range Δε p0 ¼ plastic strain range of specimen without LSP Δε LSP p ¼ plastic strain range of specimen with LSP Δε LSP;D¼0 p ¼ plastic strain range of the original specimen with LSP Δε LSP;D p ¼ plastic strain range for the damaged specimen by LSP

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Improvement of Laser Shock Peening Depth Through Regulation of Surface Optical Absorption

Yan

Zhu

et al. 2021

Adv Materials Inter

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Higher depths at the millimeter scale (1-2 mm), along with greater magnitudes, have been reported after the NLSP of Ti6Al4V titanium alloy, [2,10] 2024, [11] 6061, [12] and 7075 [13] aluminum alloys. Elaborated laser systems with large power densities are currently required to increase the peak pressure to enable a high input of energy (slightly over 10 GW cm -2 ) during the interaction between the incident laser and metals. [14] The critical power density threshold for the confinement layer breakdown is validated to limit the possible peak pressure. [15][16][17] Changing the wavelength of the incident laser from 1064 to 532 nm decreases the breakdown threshold of the confining water layers from 10 to 6 GW cm -2 , and the maximum peak pressure from ≈5.5 to 4.5 GPa. [18,19] Compressive residual stresses can also be generated deep below the peened surface by multiple or overlapping laser pulses. [20,21] The reduced attenuation of the shock wave indicates an increased depth for the plastic-deformed layer during subsequent peening, while the affected depths usually reach saturated border values within three to five impacts. [22,23] Additionally, femtosecond laser shock peening is applied to induce a shallower affected depth and a limited compressive layer owing to the high instantaneous power density. [24] It is necessary to increase the surface optical absorption and associated energy conversion at higher affected depths in NLSP. The surface optical absorption property determines the thermal energy fraction, [25,26] with a value of ≈0.2 utilized in investigations. [27,28] In this case, optical absorption is defined by the surface morphology of the metal rather than its intrinsic absorptance. [29] Various absorption mechanisms with different optical behaviors are found in the structures induced using lithographic and chemical techniques. [30,31] These essentially originate from selective absorption responses such as the surface plasmon resonance, magnetic-polariton, geometric optical response, and metamaterial resonances. [29,[32][33][34] A nanoscale structure and laser-induced periodic surface structure can enhance the absorption of laser energy by the reconstruction of surface electromagnetic distributions. [35] The absorption of light is enhanced on structured surfaces by multiple reflections based on the angular dependence of Fresnel absorption. [35] The absorption spectrum of femtosecond laser treated surfaces increased sharply over a wide range of wavelengths of incident Laser shock peening is conducted to enhance the mechanical properties of metals. Efficient optical absorption of metal surface is desirable to increase the laser shock peening depth. In this work, a method is proposed to regulate the absorption behavior by surface colorizing to increase the affected depth and magnitude of nanosecond laser shock peening (NLSP). Colorized samples are fabricated with high absorption of 400-1500 nm, which is 89% higher than that of un-colorized samples. This regulated optical response is attributed to the multi-ref...

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Laser shock processing with two different laser sources on 2050‐T8 aluminum alloy

Cited by 16 publications

References 7 publications

Random-type scanning patterns in laser shock peening without absorbing coating in 2024-T351 Al alloy: A solution to reduce residual stress anisotropy

Random-type scanning patterns in laser shock peening without absorbing coating in 2024-T351 Al alloy: A solution to reduce residual stress anisotropy

Residual life prediction for healing fatigue damaged copper film by laser shock peening

Improvement of Laser Shock Peening Depth Through Regulation of Surface Optical Absorption

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