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利用新型聚偏1,1-二氟乙烯(PVDF)压电传感器,实现了对激光引发的冲击波压力的实时测量,得到激光引发的冲击波峰压在铝中成指数型的衰减规律;观测了不同约束层材料在铝靶表面产生的激光冲击波,研究了不同约束层对冲击效果的影响;最后用激光冲击强化装置对7050-T7451航空铝合金结构材料进行了冲击强化处理,对试件激光冲击区存在的残余压应力及位错密度进行了测量。结果显示经激光冲击处理的试件表面具有极高的残余压应力,可达-200 MPa以上。激光冲击处理后铝合金的位错密度得到显著的提高,疲劳寿命提高到175%~428%。这些重要结果对激光冲击改性处理技术的实际应用具有指导性作用。
Using the new PVDF piezoelectric sensor, real-time measurement of laser-induced shock wave pressure was achieved, and the exponential attenuation of laser-induced shock wave peak in aluminum was obtained. The influence of different confinement layers on the impact effect was studied by using the laser shock wave generated by the constraining layer material on the surface of the aluminum target. Finally, the impact strength of the 7050-T7451 aviation aluminum alloy structure material was enhanced by laser shock intensifier, Existence of residual compressive stress and dislocation density were measured. The results show that the surface of the specimen treated by laser shock has a very high residual compressive stress of up to -200 MPa. The dislocation density of aluminum alloy after laser shock treatment has been significantly improved, the fatigue life increased to 175% ~ 428%. These important results play an instructive role in the practical application of laser shock modification techniques.