scholarly journals Investigation of Corrosion Behaviour of Aluminium Alloy Subjected to Laser Shock Peening without a Protective Coating

2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
U. Trdan ◽  
J. Grum
Keyword(s):  
Shock Waves ◽  
Protective Coating ◽  
Corrosion Behaviour ◽  
Laser Shock Peening ◽  
Anodic Current Density ◽  
Strain Rates ◽  
Laser Shock ◽  
Near Surface ◽  
Shock Peening ◽  
Chloride Environment

The effect of shock waves and strain hardening of laser shock peening without protective coating (LSPwC) on alloy AA 6082-T651 was investigated. Analysis of residual stresses confirmed high compression in the near surface layer due to the ultrahigh plastic strains and strain rates induced by multiple laser shock waves. Corrosion tests in a chloride environment were carried out to determine resistance to localised attack, which was also verified on SEM/EDS. OCP transients confirmed an improved condition, that is, a more positive and stable potential after LSPwC treatment. Moreover, polarisation resistance of the LSPwC treated specimen was by a factor of 25 higher compared to the untreated specimen. Analysis of voltammograms confirmed an improved enhanced region of passivity and significantly smaller anodic current density of the LSPwC specimen compared to the untreated one. Through SEM, reduction of pitting attack at the LSPwC specimen surface was confirmed, despite its increased roughness.

Numerical Investigation of Opposing Dual Sided Micro Scale Laser Shock Peening

2006 ◽  
Author(s):  
Yajun Fan ◽  
Youneng Wang ◽  
Sinisa Vukelic ◽  
Y. Lawrence Yao
Keyword(s):  
Residual Stress ◽  
Shock Waves ◽  
Laser Shock Peening ◽  
Time Lags ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Strain Rate Effects ◽  
Micro Scale ◽  
Stress Profiles ◽  
Shock Peening

Laser shock peening (LSP) is an innovative process which imparts compressive residual stresses in the processed surface of metallic parts to significantly improve fatigue life and fatigue strength of this part. In opposing dual sided LSP, the workpiece can be simultaneously irradiated or irradiated with different time lags to create different surface residual stress patterns by virtue of the interaction between the opposing shock waves. In this work, a finite element model, in which the hydrodynamic behavior of the material and the deviatoric behavior including work hardening and strain rate effects were considered was applied to predict residual stress distributions in the processed surface induced under various conditions of the opposing dual sided micro scale laser shock peening. Thus the shock waves from each surface will interact in different ways through the thickness resulting in more complex residual stress profiles. Additionally, when treating a thin section, opposing dual sided peening is expected to avoid harmful effects such as spalling and fracture because the pressures on the opposite surfaces of the target balance one another and prohibit excessive deformation of the target. In order to better understand the wave-wave interactions under different conditions, the residual stress profiles corresponding to various workpiece thicknesses and various irradiation times were evaluated.

Numerical Investigation of Opposing Dual Sided Microscale Laser Shock Peening

2006 ◽  
Vol 129 (2) ◽  
pp. 256-264 ◽  
Author(s):  
Yajun Fan ◽  
Youneng Wang ◽  
Sinisa Vukelic ◽  
Y. Lawrence Yao
Keyword(s):  
Residual Stress ◽  
Shock Waves ◽  
Element Model ◽  
Laser Shock Peening ◽  
Time Lags ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Strain Rate Effects ◽  
Stress Profiles ◽  
Shock Peening

Laser shock peening (LSP) is an innovative process which imparts compressive residual stresses in the processed surface of metallic parts to significantly improve fatigue life and fatigue strength of this part. In opposing dual sided LSP, the workpiece can be simultaneously irradiated or irradiated with different time lags to create different surface residual stress patterns by virtue of the interaction between the opposing shock waves. In this work, a finite element model, in which the hydrodynamic behavior of the material and the deviatoric behavior including work hardening and strain rate effects were considered, was applied to predict residual stress distributions in the processed surface induced under various conditions of the opposing dual sided microscale laser shock peening. Thus the shock waves from each surface will interact in different ways through the thickness resulting in more complex residual stress profiles. Additionally, when treating a thin section, opposing dual sided peening is expected to avoid harmful effects such as spalling and fracture because the pressures on the opposite surfaces of the target balance one another and prohibit excessive deformation of the target. In order to better understand the wave–wave interactions under different conditions, the residual stress profiles corresponding to various workpiece thicknesses and various irradiation times were evaluated.

scholarly journals The Effect of Laser Shock Peening with and without Protective Coating on Intergranular Corrosion of Sensitized AA5083

2021 ◽  
pp. 109925
Author(s):  
Jan Kaufman ◽  
Jan Racek ◽  
Miroslav Cieslar ◽  
Peter Minarík ◽  
Matthew A. Steiner ◽  
...  
Keyword(s):  
Protective Coating ◽  
Intergranular Corrosion ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

Study of the Parameters of Laser-Induced Shock Waves for Laser Shock Peening of Silicon

JETP Letters ◽  
2020 ◽  
Vol 112 (11) ◽  
pp. 739-744
Author(s):  
E. I. Mareev ◽  
B. V. Rumiantsev ◽  
F. V. Potemkin
Keyword(s):  
Shock Waves ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

Residual Stress State and Fatigue Behaviour of Laser Shock Peened Titanium Alloys

2006 ◽  
Vol 524-525 ◽  
pp. 129-134 ◽  
Author(s):  
I. Altenberger ◽  
Yuji Sano ◽  
M.A. Cherif ◽  
Ivan Nikitin ◽  
Berthold Scholtes
Keyword(s):  
Residual Stress ◽  
Titanium Alloys ◽  
Cold Work ◽  
Fatigue Behaviour ◽  
Laser Shock Peening ◽  
Fatigue Properties ◽  
Stress Profile ◽  
Laser Shock ◽  
Near Surface ◽  
Shock Peening

Laser shock peening is a very effective mechanical surface treatment to enhance the fatigue behaviour of highly stressed components. In this work the effect of different laser shock peening conditions on the residual stress depth profile and fatigue behaviour without any sacrificial coating layer is investigated for two high strength titanium alloys, Ti-6Al-4V and Timetal LCB. The results show that the optimization of peening conditions is crucial to obtain excellent fatigue properties. Especially, power density, spot size and coverage severely influence the residual stress profile of laser shock peened Ti-6Al-4V and Timetal LCB specimens. For both alloys, subsurface as well as surface compressive residual stress peaks can be obtained by varying the peening conditions. In general, Timetal LCB exhibits steeper stress gradients than Ti-6Al-4V for identical peening conditions. The main parameters affecting the fatigue life are near-surface cold work and compressive residual stresses.

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