FEM Study and Characterization on Laser Shock Peening of TC4 Titanium Alloy Structure

2014 ◽  
Vol 651-653 ◽  
pp. 34-37 ◽  
Author(s):  
Chen Hu ◽  
Hou Jun Qi ◽  
Xing Hui Zhang ◽  
Zhi Gang Che ◽  
Shu Ying Zhang

This paper, using the finite element software ABAQUS, establishes the model of laser shock peening (LSP) of TC4 titanium alloy, and analyzes the influence of different parameters on the residual stress of TC4 titanium alloy and plastic deformation. The results show that LSP can make the surface of TC4 titanium alloy have large compressive stress and plastic deformation, hardness and prolong the fatigue life of materials. Laser energy and the impact frequency are the main factor of surface residual stress effects. The multi-point LSP can perform processing enhanced in surface area, and form residual compressive stress on the surface of the material and in a certain depth.

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 1878
Author(s):  
Xiangfan Nie ◽  
Yuyuan Tang ◽  
Feifan Zhao ◽  
Li Yan ◽  
Haonian Wu ◽  
...  

In the laser shock peening process of titanium alloy thin blades, a shock wave will be repeatedly reflected and coupled in the blades, resulting in the failure of the formation of a gradient residual compressive stress layer, which is the key to improve fatigue performance and resist foreign object impact. This paper takes TC17 titanium alloy sheet as the research object to reveal the influence mechanism on residual stress-strain profile of shock wave reflection-coupling by shock wave propagation and key position dynamic response. Based on the result of influence mechanism, two wave transmission methods are proposed to regulate shock wave in order to reduce the intensity of shock wave reflection. The analysis shows that the high strength stress be formed when the shock wave is reflected and coupled in the sheet, which causes the re-plastic deformation and the decrease of transverse plastic strain. This eventually leads to residual tensile stress up to 410 MPa being formed within a 0.5 mm radial direction and 0.3 mm deep of the spot range. The use of "soft" and "hard" wave-transmitting layers greatly reduces the shock wave reflection intensity, and under the condition of the "hard" wave-transmitting layer, a better impedance matching is achieved, resulting in a residual compressive stress of about 400 MPa.


2013 ◽  
Vol 681 ◽  
pp. 266-270 ◽  
Author(s):  
Xiang Fan Nie ◽  
Wei Feng He ◽  
Liu Cheng Zhou ◽  
Yu Qin Li ◽  
Yan Chai

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.


Applied laser ◽  
2013 ◽  
Vol 33 (2) ◽  
pp. 131-138
Author(s):  
杨晶 Yang Jing ◽  
周建忠 Zhou Jianzhong ◽  
黄舒 Huang Shu ◽  
左立党 Zuo Lidang ◽  
季杏露 Ji Xinglu ◽  
...  

2020 ◽  
Vol 47 (5) ◽  
pp. 0502006
Author(s):  
刘亚鹏 Liu Yapeng ◽  
史志俊 Shi Zhijun ◽  
赵一昭 Zhao Yizhao ◽  
朱亮 Zhu Liang ◽  
刘马宝 Liu Mabao

2011 ◽  
Vol 84-85 ◽  
pp. 471-475 ◽  
Author(s):  
Wei Feng He ◽  
Yu Qin Li ◽  
Xiang Fan Nie ◽  
Rui Jun Liu ◽  
Qi Peng Li

In this paper, the microstructure and hardness of Ti-5Al-2Sn-2Zr-4Mo-4Cr titanium alloy with and without laser shock peening (LSP) were examined and compared. The titanium alloy samples were laser shock peened with different layers at the same power density. The microscopic structure after LSP are tested and analyzed by SEM and TEM. The results indicated that LSP changed the microstructure evidently. After 3 layers laser shock peening, there are nanocrystallization in the LSP zone. The shock wave provided high strain rate deformation and generated high-density dislocations in the material. Multiple severe plastic deformation caused by 3 to 5 LSP layers helped to rearrange the resultant dislocation, to form dislocation networks, leading to the formation of nanocrystallites. On the other hand, the microhardness across the polished surfaces of the titanium materials with and without LSP was measured. It is obvious that the laser shock peening improved the microhardness of the Ti-5Al-2Sn-2Zr-4Mo-4Cr for about 16% at the surface, and the affected depth is about 300 microns from the surface.


Metals ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 107
Author(s):  
Vasily Pozdnyakov ◽  
Sören Keller ◽  
Nikolai Kashaev ◽  
Benjamin Klusemann ◽  
Jens Oberrath

Laser shock peening (LSP) is a surface modification technique to improve the mechanical properties of metals and alloys, where physical phenomena are difficult to investigate, due to short time scales and extreme physical values. In this regard, simulations can significantly contribute to understand the underlying physics. In this paper, a coupled simulation approach for LSP is presented. A global model of laser–matter–plasma interaction is applied to determine the plasma pressure, which is used as surface loading in finite element (FE) simulations in order to predict residual stress (RS) profiles in the target material. The coupled model is applied to the LSP of AA2198-T3 with water confinement, 3×3mm2 square focus and 20 ns laser pulse duration. This investigation considers the variation in laser pulse energy (3 J and 5 J) and different protective coatings (none, aluminum and steel foil). A sensitivity analysis is conducted to evaluate the impact of parameter inaccuracies of the global model on the resulting RS. Adjustment of the global model to different laser pulse energies and coating materials allows us to compute the temporal pressure distributions to predict RS with FE simulations, which are in good agreement with the measurements.


2016 ◽  
Vol 43 (7) ◽  
pp. 0702006
Author(s):  
李东霖 Li Donglin ◽  
何卫锋 He Weifeng ◽  
游熙 You Xi ◽  
张金 Zhang Jin ◽  
罗思海 Luo Sihai ◽  
...  

2019 ◽  
Vol 943 ◽  
pp. 20-25
Author(s):  
Ran Zhu ◽  
Yong Kang Zhang ◽  
Gui Fang Sun ◽  
Pu Li

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.


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