Improvement of Damping Property and Its Effects on the Vibration Fatigue in Ti6Al4V Titanium Alloy Treated by Warm Laser Shock Peening

In order to increase the vibration life of Ti6Al4V titanium alloy, warm laser shock peening (WLSP) is used to improve the damping properties and thus decrease the vibration stress in this study. Firstly, the Ti6Al4V specimens are treated by WLSP at different treatment temperatures from 200 °C to 350 °C. Then the damping ratios of untreated and WLSPed samples are obtained by impact modal tests, and the improvement of damping properties generated byWLSP is analyzed by the microstructures in Ti6Al4V titanium alloy. Moreover, the finite element simulations are utilized to study the vibration amplitude and stress during the frequency response process. Finally, the vibration fatigue tests are carried out and the fatigue fracture morphology is observed by the scanning electron microscope. The results indicate that the damping ratios of WLSPed specimens increase with the increasing treatment temperatures. This is because elevated temperatures during WLSP can effectively increase the α phase colonies and the interphase boundaries, which can significantly increase the internal friction of materials. Moreover, due to the increasing material damping ratio, the displacement and stresses during vibration were both reduced greatly by 350 °C-WLSP, which can significantly decrease the fatigue crack growth rate and thus improve the vibration fatigue life of Ti6Al4V titanium alloy.

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Effect of process temperature on mechanical properties of Ti6Al4V titanium alloy with warm laser shock peening

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/770/1/012080 ◽

2020 ◽

Vol 770 ◽

pp. 012080

Author(s):

X L Pan ◽

L C Zhou ◽

W F He ◽

X S Shi ◽

R K Li ◽

...

Keyword(s):

Mechanical Properties ◽

Titanium Alloy ◽

Laser Shock Peening ◽

Process Temperature ◽

Laser Shock ◽

Ti6al4v Titanium Alloy ◽

Shock Peening

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Effect of dynamic recrystallization on texture orientation and grain refinement of Ti6Al4V titanium alloy subjected to laser shock peening

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2020.156672 ◽

2021 ◽

Vol 850 ◽

pp. 156672 ◽

Cited By ~ 3

Author(s):

Xinlei Pan ◽

Xuede Wang ◽

Zeng Tian ◽

Weifeng He ◽

Xiaosong Shi ◽

...

Keyword(s):

Titanium Alloy ◽

Dynamic Recrystallization ◽

Grain Refinement ◽

Laser Shock Peening ◽

Laser Shock ◽

Ti6al4v Titanium Alloy ◽

Texture Orientation ◽

Shock Peening

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Improving High Cycle Fatigue Performance of Gas Tungsten Arc Welded Ti6Al4V Titanium Alloy by Warm Laser Shock Peening

International Journal of Fatigue ◽

10.1016/j.ijfatigue.2021.106270 ◽

2021 ◽

pp. 106270

Author(s):

Xiaotai Feng ◽

Xinlei Pan ◽

Weifeng He ◽

Ping Liu ◽

Zhibin An ◽

...

Keyword(s):

Titanium Alloy ◽

High Cycle Fatigue ◽

Laser Shock Peening ◽

Fatigue Performance ◽

Cycle Fatigue ◽

Laser Shock ◽

Ti6al4v Titanium Alloy ◽

Gas Tungsten Arc ◽

Gas Tungsten ◽

Shock Peening

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Effect of Residual Stress on S–N Curves and Fracture Morphology of Ti6Al4V Titanium Alloy after Laser Shock Peening without Protective Coating

Materials ◽

10.3390/ma12223799 ◽

2019 ◽

Vol 12 (22) ◽

pp. 3799 ◽

Cited By ~ 1

Author(s):

Xinlei Pan ◽

Xiang Li ◽

Liucheng Zhou ◽

Xiaotai Feng ◽

Sihai Luo ◽

...

Keyword(s):

Residual Stress ◽

Titanium Alloy ◽

Fatigue Life ◽

Compressive Residual Stress ◽

Fracture Morphology ◽

High Amplitude ◽

Laser Shock ◽

Ti6al4v Titanium Alloy ◽

Before And After ◽

Shock Peening

In this paper, the effect of residual stress on the stress–life (S–N) curve and fracture morphology characteristics of Ti6Al4V titanium alloy after laser shock peening (LSP) without protective coating was experimentally investigated. The fatigue test and residual stress measurement were conducted on specimens before and after the LSP process. It was shown that LSP produced a high-amplitude compressive residual stress field on the surface of the specimen. After the LSP process, the fatigue life limit was increased by 16%, and the S–N curve shifted upward. Then, based on the theory of mean stress, the mechanism whereby the compressive residual stress improves the fatigue life of Ti6Al4V titanium alloy was analyzed. It indicated the improvement in fatigue life was because of the high-amplitude compressive residual stress on the surface and in depth induced by LSP to reduce the tensile stress produced by external loading. In addition, the scanning electron microscope (SEM) pattern of fatigue fracture demonstrated distinct differences in the fracture morphology before and after LSP. After LSP, the crack initiation sites of the samples moved to the subsurface where it was difficult for fatigue cracks initiating here. Moreover, after the LSP process, there were high density of fatigue striations and many secondary cracks on the fracture of the treated specimen.

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