激光冲击、喷丸及其复合强化对TB6钛合金表面完整性及轴向疲劳性能的影响

 为了提升TB6钛合金旋翼的疲劳性能，研究了喷丸、激光冲击及两者的复合工艺等3种表面强化方法对钛合金表面完整性及高周疲劳性能的影响规律。采用白光干涉仪、X射线残余应力测试仪和扫描电子显微镜分别对加工前后试样的表面形貌、表面残余应力分布和微观组织等表面完整性特征参数进行了表征，并采用疲劳试验机分别测试了轴向应力疲劳寿命和疲劳极限。结果表明，在相同加载条件下，相比磨削试样，采用单一的激光冲击试样的轴向应力疲劳寿命提高了32.2倍，而单一的喷丸和激光冲击+喷丸复合强化的试样疲劳寿命均提高了至少126.4倍。激光冲击+喷丸复合强化表现出比单一的喷丸强化更优的疲劳极限增益效果。

Effect of laser shock peeing,shot peeing and their combination treatment on surface integrity and axial fatigue property of TB6 titanium alloy

To improve the fatigue performance of aircraft rotor of TB6 titanium alloy, the effects of laser shock peening (LSP), shot peening (SP) and their combination processing methods on surface integrity and axial fatigue property of the titanium alloy are investigated. The surface topography, residual stress distribution and microstructure are characterized by white light interferometer, X-ray diffraction stress tester and scanning electron microscope. The axial fatigue life and limit are investigated by fatigue tester. Results show that compared with the grinding (GD) specimen under the same test conditions, the fatigue life of LSP specimens is improved by 32.2 times, while the fatigue lifes of SP and the combination processing specimens are both increased by at least 126.4 times. The combination processing method exhibits better improvement for fatigue limit than the SP method.