Numerical Simulation and Response Analysis of Residual Stress Induced by Micro-Scale Laser Shock Peening in TiN Film

2012 ◽  
Vol 452-453 ◽  
pp. 741-745
Author(s):  
Hong Yan Ruan ◽  
Xiao Jiang Xie ◽  
Shu Huang ◽  
Jian Zhong Zhou
Keyword(s):  
Residual Stress ◽  
Power Density ◽  
Process Parameters ◽  
Laser Power ◽  
Compressive Residual Stress ◽  
Laser Power Density ◽  
Laser Shock ◽  
Laser Process ◽  
Tin Film ◽  
Shock Peening

The ABAQUS software was used to analyze the residual stress of TiN film treated by the single point micro-scale laser shock peening (μLSP). In view of the multi-factor effect of μLSP, the response surface methodology (RSM) of Design-Expert software was utilized to analyze the influence of laser process parameters on the residual stress in TiN film, based on the Box-Behnken experimental design methods, as a result, optimal combination of the laser process parameters was obtained. The results showed that μLSP can transform the tensile residual stress in the TiN film into the compressive residual stress, the compressive residual stress was gradually increasing with the increased laser power density, when the laser power density was 8 GW/cm2, the maximum compressive residual stress of the film surface was up to -350.48 MPa. In addition, as the laser power density increased, the maximum compressive residual stress was moving away from the spot center. The optimal combination of the laser process parameters of μLSP was obtained by the RSM, the laser power density was 7.6 GW/cm2, laser spot diameter was 283 μm, and the number of shocking was 2 times. Simulation results of the average residual stress was -248.76 MPa, while the predicting result of regression model was -245.31 MPa, the error was just 1.38 %. The results showed that μLSP was feasible for improving the residual stress distribution of TiN film, and the RSM can effectively optimize the process parameters of μLSP.

scholarly journals Study on Residual Stress Distribution of 7050 Aluminum Sheet with Groove after Laser Shock Peening

2019 ◽  
Vol 37 (4) ◽  
pp. 643-649
Author(s):  
Yong Du ◽  
Yu'e Ma ◽  
Lei Gou ◽  
Chao Guo ◽  
Bo Li ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stress Distribution ◽  
Laser Power ◽  
Laser Power Density ◽  
Residual Stress Distribution ◽  
Laser Shock Peening ◽  
Aluminum Sheet ◽  
Bottom Surface ◽  
Laser Shock ◽  
Shock Peening

In order to study the residual stress profile of 7050-T7451 aluminum sheet with groove after laser shock peening (LSP), the residual stress distribution was measured. It is shown that the residual stress decreases gradually from the center to the edge of groove; and then there is the minimum value at the edge of the groove bottom surface. By using ABAQUS software to establish three-dimensional finite element model for 7050 aluminum sheet with groove, and the load was applied by VDLOAD subroutine. The finite element analysis was performed and the analysis results were compared with the experimental measurements, in which the both the results agree with each other very well. And then the residual stress distribution of the sheet was analyzed after laser shock peening under different laser processing parameters. It is shown that the residual stress decreases firstly and then increases with the rise of laser power density from 0.84 GW/cm2 to 5.29 GW/cm2. And the residual stress obtains the minimum value -230 MPa at the laser power density of 3.06 GW/cm2. With the increasing of spot diameter from 4 mm to 6 mm, the residual stress increased from -214 MPa to -30 MPa. With the increasing of laser pulse width from 10 ns to 40 ns, the residual stress decreased from -21 MPa to -288 MPa; and the depth of the compressive residual stress increased too. For all simulations under different LSP parameters, the minimum surface residual stress achieved at the bottom surface of the groove as well.

scholarly journals Effect of Laser Shock Peening on Fretting Fatigue Life of TC11 Titanium Alloy

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4711
Author(s):  
Xufeng Yang ◽  
Hongjian Zhang ◽  
Haitao Cui ◽  
Changlong Wen
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Power Density ◽  
Laser Power ◽  
Fretting Fatigue ◽  
Laser Power Density ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening ◽  
Tc11 Titanium Alloy

The purpose of this paper is to investigate the performance of laser shock peening (LSP) subjected to fretting fatigue with TC11 titanium alloy specimens and pads. Three laser power densities (3.2 GW/cm2, 4.8 GW/cm2 and 6.4 GW/cm2) of LSP were chosen and tested using manufactured fretting fatigue apparatus. The experimental results show that the LSP surface treatment significantly improves the fretting fatigue lives of the fretting specimens, and the fretting fatigue life increases most when the laser power density is 4.8 GW/cm2. It is also found that with the increase of the laser power density, the fatigue crack initiation location tends to move from the surface to the interior of the specimen.

Experimental Study on Testing Ni-Containing Stainless Steel Protective Coatings by Pulsed Laser Scratching

2010 ◽  
Vol 43 ◽  
pp. 651-656
Author(s):  
Ai Xin Feng ◽  
Yu Peng Cao ◽  
Chuan Chao Xu ◽  
Huai Yang Sun ◽  
Gui Fen Ni ◽  
...  
Keyword(s):  
Residual Stress ◽  
Stainless Steel ◽  
Power Density ◽  
Laser Power ◽  
Protective Coatings ◽  
Three Dimensional ◽  
Pulsed Laser ◽  
Laser Power Density ◽  
The Matrix ◽  
The Impact

In the experiment, we use pulsed laser to conduct discrete scratching on Ni-containing stainless steel protective coatings to test residual stress situation after the matrix is scratched; then to analyze the the impact of the impact stress wave on coating - substrate bonding strength according to the test results, finally to infer the laser power density range within which it occurs coating failure. The study shows that: after laser discrete scratching, the residual stress of the center of the laser-loaded point on matrix surface gradually reduces when the pulsed laser power density increases. The matrix produces a corresponding residual compressive stress under the laser power density reaches a certain value. The actual failure threshold values are 12.006 GW/cm2, 11.829GW/cm2 and 12.193GW/cm2 measured by the three-dimensional topography instrument testing the discrete scratch point of three groups of samples and verified by using a microscope

Massive Parallel Laser Shock Peening: Simulation, Verification, and Analysis

2005 ◽  
Author(s):  
A. W. Warren ◽  
Y. B. Guo ◽  
S. C. Chen
Keyword(s):  
Residual Stress ◽  
Surface Integrity ◽  
Compressive Residual Stress ◽  
Laser Intensity ◽  
Shock Pressure ◽  
Laser Shock Peening ◽  
Massively Parallel ◽  
Laser Shock ◽  
Laser Material ◽  
Shock Peening

Laser shock peening (LSP) is a surface treatment process to improve the surface integrity of metallic components. The nearly pure mechanical process of LSP results in favorable surface integrity such as compressive residual stress and improved surface material properties. Since LSP is a transient process with laser pulse duration time on the order of 40 ns, real time in-situ measurement of laser/material interaction is very challenging, if not impossible. A fundamental understanding of laser/material interactions is essential for LSP planning. Previous finite element simulations of LSP have been limited to a single laser shock location for both two and three dimensional modeling. However, actual LSP are performed in a massively parallel mode which involves almost simultaneous multi-laser/material interactions in order to induce uniform compressive residual stress across the entire surface of the workpiece. The massively parallel laser/material interactions have a significant compound/interfering effect on the resulting surface integrity of the workpiece. The numerical simulation of shock pressure as a function of time and space during LSP is another critical problem. The purpose of this paper is to investigate the effects of parallel multiple laser/material interactions on the stress/strain distributions in the workpiece during LSP of AISI 52100 steel. FEA simulations of LSP in single and multiple passes were performed with the developed spatial and temporal shock pressure model via a subroutine. The simulated residual stresses agree with the measured data in nature and trend, while magnitude can be influenced by the interactions between neighboring peening zones and the locations of residual stress measurement. Design-of-experiment (DOE) based simulations of massive parallel LSP were also performed to determine the effects of laser intensity, laser spot size, and peening spacing on stresses and strains. Increasing the laser intensity increases both the stress magnitude and affected depth. The use of smaller laser spot sizes decreases the largest magnitude of residual stress and also decreases the depth affected by LSP. Larger spot sizes have less energy attenuation and cause more plastic deformation. Spacing between peening zones is critical for the uniformity of mechanical properties across the surface. The greatest uniformity and largest stress magnitudes are achieved by overlapping of the laser spots.

scholarly journals Investigation on Residual Stress Loss during Laser Peen Texturing of 316L Stainless Steel

2019 ◽  
Vol 9 (17) ◽  
pp. 3511 ◽  
Author(s):  
Kangmei Li ◽  
Yifei Wang ◽  
Yu Cai ◽  
Jun Hu
Keyword(s):  
Residual Stress ◽  
Compressive Stress ◽  
Power Density ◽  
Laser Power ◽  
Surface Deformation ◽  
Laser Power Density ◽  
Residual Compressive Stress ◽  
Laser Spot ◽  
Residual Tensile Stress ◽  
Spot Radius

Laser peen texturing (LPT) is a novelty way of surface texturing based on laser shock processing. One of the most important benefits of LPT is that it can not only fabricate surface textures but also induce residual compressive stress for the target material. However, the residual stress loss leads to partial loss of residual compressive stress and even causes residual tensile stress at the laser spot center. This phenomenon is not conducive to improving the mechanical properties of materials. In this study, a numerical simulation model of LPT was developed and validated by comparison of surface deformation with experiments. In order to investigate the phenomenon of residual stress loss quantitatively, an evaluation method of residual stress field was proposed. The effects of laser power density and laser spot radius on the residual stress, especially the residual stress loss, were systematically investigated. It is found that with the increase of laser power density or laser spot radius, the thickness of residual compressive layer in depth direction becomes larger. However, both the magnitude and the affecting zone size of residual stress loss will be increased, which implies a more severe residual stress loss phenomenon.

Effects of laser power density and initial grain size in laser shock punching of pure copper foil

2018 ◽  
Vol 105 ◽  
pp. 35-42 ◽  
Author(s):  
Chao Zheng ◽  
Xiu Zhang ◽  
Yiliang Zhang ◽  
Zhong Ji ◽  
Yiguo Luan ◽  
...  
Keyword(s):  
Grain Size ◽  
Power Density ◽  
Laser Power ◽  
Copper Foil ◽  
Pure Copper ◽  
Laser Power Density ◽  
Laser Shock

Study on Strengthening Mechanism of Microscale Laser Shock Peening

2010 ◽  
Vol 431-432 ◽  
pp. 221-224
Author(s):  
Yu Jie Fan ◽  
Jian Zhong Zhou ◽  
Shu Huang ◽  
Min Wang ◽  
Yin Bo Zhu ◽  
...  
Keyword(s):  
Residual Stress ◽  
Surface Energy ◽  
Grain Boundary ◽  
Compressive Residual Stress ◽  
Influence Factors ◽  
Strengthening Mechanism ◽  
Point Of View ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Shock Peening

Microscale laser shock peening (μLSP) is a novel surface treating technology which oriented to microscale metal components in MEMS. Beneficial compressive residual stress is induced at the shocked region to improve the performance of microstructure based on wave-solid interactions. In this paper, the basic principle of μLSP and mechanism of wave-solid coupling were introduced, the influence factors on strengthening effects, such as micro-size effect, anisotropy, dislocation, stacking fault, grain boundary and surface energy were discussed from the microscopic point of view, the results provide theoretical guidance for further study.

scholarly journals A parametric neutron Bragg edge imaging study of additively manufactured samples treated by laser shock peening

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Matteo Busi ◽  
Nikola Kalentics ◽  
Manuel Morgano ◽  
Seth Griffiths ◽  
Anton S. Tremsin ◽  
...  
Keyword(s):  
Residual Stress ◽  
Additive Manufacturing ◽  
Residual Stresses ◽  
Compressive Residual Stress ◽  
Laser Shock Peening ◽  
Powder Bed Fusion ◽  
Laser Shock ◽  
Laser Powder Bed Fusion ◽  
Powder Bed ◽  
Shock Peening

AbstractLaser powder bed fusion is an additive manufacturing technique extensively used for the production of metallic components. Despite this process has reached a status at which parts are produced with mechanical properties comparable to those from conventional production, it is still prone to introduce detrimental tensile residual stresses towards the surfaces along the building direction, implying negative consequences on fatigue life and resistance to crack formations. Laser shock peening (LSP) is a promising method adopted to compensate tensile residual stresses and to introduce beneficial compressive residual stress on the treated surfaces. Using neutron Bragg edge imaging, we perform a parametric study of LSP applied to 316L steel samples produced by laser powder bed fusion additive manufacturing. We include in the study the novel 3D-LSP technique, where samples are LSP treated also during the building process, at intermediate build layers. The LSP energy and spot overlap were set to either 1.0 or 1.5 J and 40$$\%$$ % or 80$$\%$$ % respectively. The results support the use of 3D-LSP treatment with the higher LSP laser energy and overlap applied, which showed a relative increase of surface compressive residual stress (CRS) and CRS depth by 54$$\%$$ % and 104$$\%$$ % respectively, compared to the conventional LSP treatment.

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