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.

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.

Effect of Laser Shock Peening on Surface Residual Stress and Plastically Affected Depth of TC11 Titanium Alloy

2019 ◽  
Vol 943 ◽  
pp. 20-25
Author(s):  
Ran Zhu ◽  
Yong Kang Zhang ◽  
Gui Fang Sun ◽  
Pu Li
Keyword(s):  
Residual Stress ◽  
Finite Element ◽  
Titanium Alloy ◽  
Finite Element Model ◽  
Element Model ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
Surface Residual Stress ◽  
Shock Peening ◽  
Tc11 Titanium Alloy

The confined laser shock peening (LSP) is an innovative surface treatment technique designed to improve the fatigue performance of materials by imparting compressive residual stresses into materials. A 3D finite element model was developed to predict the surface residual stress and plastically affected depth of the TC11 titanium alloy after LSP. The modeling procedure consists of two successive explicit analysis steps. The performance of finite element model was verified by comparing simulated results with the experimental data. With the validated finite element model, the influence of the process parameters (LSP path, thickness of the sample, number of impacts) was investigated on the surface residual stress and plastically affected depth of the TC11 titanium alloy after LSP. Some simulated results can be used to mentor the optimization of the process parameters of LSP.

Characterization of TC17 Titanium Alloy Treated by Square-Spot Laser Shock Peening

2013 ◽  
Vol 652-654 ◽  
pp. 2378-2383 ◽  
Author(s):  
Zi Wen Cao ◽  
Shui Li Gong ◽  
Yu Gao
Keyword(s):  
Titanium Alloy ◽  
Fatigue Life ◽  
Residual Stresses ◽  
Stress Gradient ◽  
Laser Shock Peening ◽  
Fatigue Performance ◽  
Specimen Thickness ◽  
Laser Shock ◽  
Shock Peening ◽  
Square Spot

Laser shock peening (LSP) is widely known as a cold-worked surface treatment, and this technology has been to greatly improve the fatigue life of many metallic components. Our works focused on laser shock peening with Nd: glass laser system (pulse duration 30ns) and square laser spot size of 4mm×4mm for TC17 titanium alloy. Surface morphology, residual stresses and fatigue performance had been studied for TC17 alloy specimens and blades processed by LSP treatment. The results show that plastic strains in shocked dents become more homogeneous than ones produced by original circle spot with gaussian energy distribution. Surface residual stresses which measured using x-ray diffraction method showed different characteristic as varying specimen thickness, and LSP with overlapping ratio of 8% provided uniform residual stresses on peened surface. Low fluence peening which was implemented at borderline of peened surface was effective to diminish the stress gradient. Compared with mechanical shot peening, LSP attained smoother surface, lower microhardness and better fatigue performance. In a word, Square-spot LSP is an excellent way to improve fatigue life of titanium blade.

Experimental Study on Improving High-Cycle Fatigue Performance of TC11 Titanium alloy by Laser Shock Peening

2013 ◽  
Vol 40 (8) ◽  
pp. 0803006 ◽  
Author(s):  
聂祥樊 Nie Xiangfan ◽  
何卫锋 He Weifeng ◽  
臧顺来 Zang Shunlai ◽  
王学德 Wang Xuede ◽  
李玉琴 Li Yuqin
Keyword(s):  
Experimental Study ◽  
Titanium Alloy ◽  
High Cycle Fatigue ◽  
Laser Shock Peening ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Laser Shock ◽  
Shock Peening ◽  
Tc11 Titanium Alloy

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.

Effects of Laser Shock Peening on TC11 Titanium Alloy with Different Impacts

2013 ◽  
Vol 681 ◽  
pp. 266-270 ◽  
Author(s):  
Xiang Fan Nie ◽  
Wei Feng He ◽  
Liu Cheng Zhou ◽  
Yu Qin Li ◽  
Yan Chai
Keyword(s):  
Residual Stress ◽  
Titanium Alloy ◽  
Laser Shock Peening ◽  
Laser Shock ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Shock Peening ◽  
Tc11 Titanium Alloy ◽  
The Impact ◽  
Test Result

The blade, made of TC11 titanium alloy, is prone to result in fatigue failure in the formidable environment in aero-engine. So a higher performance request of the material is brought forward. In this paper, laser shock peening(LSP) as a solution is applied to TC11 titanium alloy and microstructure, residual stress and microhardness with and without LSP were examined and compared via transmission electron microscope(TEM), X ray diffraction(XRD)and microhardness tester. The TEM results indicate that a great high density of dislocations are generated and evolve into the dislocation wall, sub-boundary and grain boundary. The nanocrystallites are formed and become smaller and more uniform with greater impacts. A high compressive residual stress above -540MPa is introduced with an increasing plastically affected layer with different impacts. The microhardness test result shows that LSP can obviously increase the hardness by 20 percent or so, and the affected depth increases with the impact from 600μm to 1200μm.

Fatigue Life Recovery via Laser Shock Peening in Mechanically Damaged Aluminium Sheet; Experiments and Prediction Models

2014 ◽  
Vol 891-892 ◽  
pp. 980-985 ◽  
Author(s):  
Niall Smyth ◽  
Philip E. Irving
Keyword(s):  
Residual Stress ◽  
Fatigue Life ◽  
Prediction Models ◽  
Load Cycle ◽  
Laser Shock Peening ◽  
Stress Fields ◽  
Hole Drilling ◽  
Laser Shock ◽  
Aluminium Sheet ◽  
Shock Peening

This paper reports the effectiveness of residual stress fields induced by laser shock peening (LSP) to recover pristine fatigue life. Scratches 50 and 150 μm deep with 5 μm root radii were introduced into samples of 2024-T351 aluminium sheet 2 mm thick using a diamond tipped tool. LSP was applied along the scratch in a band 5 mm wide. Residual stress fields induced were measured using incremental hole drilling. Compressive residual stress at the surface was-78 MPa increasing to-204 MPa at a depth of 220 μm. Fatigue tests were performed on peened, unpeened, pristine and scribed samples. Scratches reduced fatigue lives by factors up to 22 and LSP restored 74% of pristine life. Unpeened samples fractured at the scratches however peened samples did not fracture at the scratches but instead on the untreated rear face of the samples. Crack initiation still occurred at the root of the scribes on or close to the first load cycle in both peened and unpeened samples. In peened samples the crack at the root of the scribe did not progress to failure, suggesting that residual stress did not affect initiation behaviour but instead FCGR. A residual stress model is presented to predict crack behaviour in peened samples.

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