激光标刻对GH4169合金疲劳性能的影响

激光标刻是航空制造领域中常用的标刻手段，为进一步加强航空工业中标刻工艺使用的规范性，提高飞机整体和关键零部件的可靠性，本文采用激光技术对GH4169合金进行标刻处理，研究了激光标刻后GH4169合金的高周疲劳性能和断裂机理。结果表明，激光标刻中值疲劳寿命为37×103 cyc，与未标刻试样相比，激光标刻处理后疲劳寿命下降了83%。激光标刻处理后，标刻处存在激光重熔层改变应力状态，缺口底端呈尖锐状，应力集中程度较高。与未标刻试样单一裂纹源相比，疲劳萌生区由多个裂纹源共同组成，扩展区初期阶段的疲劳条纹间距变大，多源裂纹在疲劳扩展区汇合后出现台阶状和脊状形态，共同作用下导致激光标刻处理后GH4169合金疲劳寿命大幅降低。

The effect of lase marking technology on fatigue propertyof GH4169 alloy

Laser marking is a commonly used method for marking in the aviation manufacturing industry. In order to further strengthen the normative use of marking technology in the aviation industry and improve the reli-ability of the aircraft as a whole and key components, the laser technology was used to mark GH4169 alloy, and the high cycle fatigue property and fracture mechanism of GH4169 alloy after laser marking were studied. The results showed that the median fatigue life of laser marking was 37×103cyc, and the fatigue life of laser marking treatment was reduced by 83% compared with that of unmarked samples. After laser marking treatment, there was laser remelting layer at the marking site to change the stress state, and the bottom of the notch was sharp with a high degree of stress concentration. Compared with the single crack source of the unmarked specimen, the fatigue initiation zone was composed of multiple crack sources, the distance between fatigue stripes in the initial stage of the propagation zone was larger, and the mul-ti-source cracks appear step-like and ridge-like shaped after the convergence of the fatigue propagation zone. Under the combined action, the fatigue life of GH4169 alloy after laser marking treatment was greatly reduced.