scholarly journals Microcracks, spall and fracture in glass: A study using short pulsed laser shock waves

1998 ◽  
Vol 83 (7) ◽  
pp. 3583-3594 ◽  
Author(s):  
Xin-Zen Li ◽  
M. Nakano ◽  
Y. Yamauchi ◽  
K. Kishida ◽  
K. A. Tanaka
Keyword(s):  
Shock Waves ◽  
Pulsed Laser ◽  
Laser Shock

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.

Laser shock waves as a tool of changing the strains in materials

2000 ◽  
Vol 288 (2) ◽  
pp. 173-176 ◽  
Author(s):  
Y. Nikiforov ◽  
V. Yakovyna ◽  
N. Berchenko
Keyword(s):  
Shock Waves ◽  
Laser Shock

Optical brake induced by laser shock waves

2021 ◽  
pp. 2050010
Author(s):  
Qiao Kang ◽  
Dongyi Shen ◽  
Jie Sun ◽  
Xin Luo ◽  
Wei Liu ◽  
...  
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Optical Method ◽  
Close Contact ◽  
Surface Friction ◽  
Laser Shock ◽  
Free Standing ◽  
Friction Forces ◽  
Optical Levitation ◽  
Contact Surfaces

We demonstrate an optical method to modify friction forces between two close-contact surfaces through laser-induced shock waves, which can strongly enhance surface friction forces in a sandwiched confinement with/without lubricant, due to the increase of pressure arising from excited shock waves. Such enhanced friction can even lead to a rotating rotor’s braking effect. Meanwhile, this shock wave-modified friction force is found to decrease under a free-standing configuration. This technique of optically controllable friction may pave the way for applications in optical levitation, transportation, and microfluidics.

Evaluation of Adhesive Strength of Oxide Layer on Carbon Steel at Elevated Temperatures

2009 ◽  
Vol 1215 ◽  
Author(s):  
Manabu Satou
Keyword(s):  
Carbon Steel ◽  
Oxide Layer ◽  
Adhesive Strength ◽  
Elevated Temperatures ◽  
Pulsed Laser ◽  
Laser Shock ◽  
Protective Layers ◽  
Base Materials ◽  
Essential Parameter ◽  
Oxidation Layers

AbstractAdhesive strength of the oxidation layers on carbon steel was evaluated by means of a laser shock method, which uses a pulsed laser to generate shock wave. Oxidation for 200 hours in air created 10-micron-thick magnetite on carbon steel. Typical strength of the layer was evaluated to be about 50MPa at ambient temperature. The adhesive strength was varied from around one-tenth of yield stress to the ultimate tensile strength of the base materials. The adhesive strength of the oxide layer depended on test temperature. It is possible that the adhesive strength becomes an essential parameter for the evaluation of the protective layers.

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.

Characteristics of High Power Laser Shock Waves and Their Cleaning Performance

2019 ◽  
Vol 11 (2) ◽  
pp. 41-46 ◽  
Author(s):  
Tae-Gon Kim ◽  
Young-Sam Yoo ◽  
Il-Ryong Son ◽  
Deoksuk Jang ◽  
Dongsik Kim ◽  
...  
Keyword(s):  
Shock Waves ◽  
High Power ◽  
Laser Shock ◽  
High Power Laser ◽  
Power Laser ◽  
Cleaning Performance

Discussion on plasma shock waves generated by high-power pulsed laser

2003 ◽  
Vol 793 ◽  
Author(s):  
ZhiHua Li ◽  
DuanMing Zhang ◽  
Li Guan
Keyword(s):  
Shock Wave ◽  
Shock Waves ◽  
Pulsed Laser ◽  
Point Explosion ◽  
Propagation Characteristics ◽  
The Difference ◽  
Plasma Shock Wave ◽  
First Time ◽  
Plasma Shock ◽  
The Ideal

ABSTRACTSedov-Taylor theory is modified to describe plasma shock waves generated in a pulsed laser ablating process. Under the reasonable asymptotic behavior and boundary conditions, the propagating rules in the global free space (including close areas and mid-far areas) of pulsed-laser-induced shock waves are established for the first time. In particular, the temporal behavior of energy causing the difference of the propagation characteristics between the practical plasma shock wave and the ideal shock wave in point explosion model is discussed in detail.

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