Laser shock peening on vibration fatigue behavior of compressor blade

According to the mechanical performance of the 1Cr11Ni2W2MoV stainless steel, the technical parameters of laser shock peening(LSP) were determined. The standard coupons with/without LSP were tested for examining the fatigue performance. It proves that LSP, with the selected parameters, can improve the stainless steel's vibration fatigue life remarkably. From the experiment results of coupons, the vibration fatigue experiment for the compressor blade in one certain aero-engine was designed according to the structure and loads of the blade. The treated zone was designed on the surface where the vibration stress is the most severe. In order to avoid macroscopical deformation, the blades were treated on both sides simultaneously. This confirms that different section parameters after LSP on the blade are within the range of design requests. The vibration fatigue results indicate that the S-N (stress-number of cycles) curve with LSP moves up as compared with that one without LSP. When the max vibratory stress was about 660MPa, the blade fatigue life with LSP was prolonged for 70%. Finally, the reasons were analyzed from the residual compressive stress and micro structure after LSP.