深冷激光喷丸对TC6钛合金阻尼特性及振动疲劳寿命的影响

Effects of Cryogenic Laser Peening on Damping Characteristics and Vibration Fatigue Life of TC6 Titanium Alloy

为了研究深冷激光喷丸(CLP)对TC6钛合金阻尼特性及振动疲劳寿命的影响,分别在室温(25℃)和深冷温度(-130℃)条件下进行激光喷丸实验,然后采用透射电子显微镜(TEM)对激光喷丸处理前后试样的微观组织进行观察,采用频率响应法对试样的阻尼比进行测试,并采用液压振动疲劳测试系统对强化后的试样进行振动疲劳测试,分析CLP处理对试样阻尼特性的影响机制及其与疲劳寿命的关系,最后采用扫描电子显微镜(SEM)对试样的振动疲劳断口进行观察。结果表明:CLP处理在试样表层产生了大量的位错和形变孪晶,可以有效提高TC6钛合金试样的阻尼比及振动疲劳寿命。

To study the effects of cryogenic laser peening(CLP)on the damping characteristics and vibration fatigue life of TC6 titanium alloy,laser peening experiments at room temperature(25℃)and cryogenic temperature(-130℃)are performed in this study.Then,the microstructures of the samples prior and subsequent to laser peening are observed using transmission electron microscopy(TEM).The damping ratios of the samples prior and subsequent to the experiment are tested using the frequency response method.The vibration fatigue test of laser-peened samples is performed using the hydraulic vibration fatigue test system.The influence mechanism of CLP treatment on damping characteristics of the samples and its relationship with fatigue life are analyzed.Finally,the vibration fatigue fractures of the samples are observed using scanning electron microscopy(SEM).Results show that the CLP treatment can produce a large number of dislocations and deformation twins on the surface of the samples,effectively improving the damping ratio and vibration fatigue life of TC6 titanium alloy.