Ironing effect on surface integrity and fatigue behavior during ultrasonic peening drilling of Ti-6Al-4V  

作　　者：Yihang LIU Deyuan ZHANG Daxi GENG Zhenyu SHAO Zehua ZHOU Zhefei SUN Yonggang JIANG Xinggang JIANG 

机构地区：[1]School of Mechanical Engineering and Automation,Beihang University,Beijing 100191,China [2]Institute of Bionic and Micro-Nano Systems,Beihang University,Beijing 100191,China [3]Aerospace Times Feihong Technology Company Limited,Beijing 100094,China

出　　处：《Chinese Journal of Aeronautics》2023年第5期486-498,共13页中国航空学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Nos.51905024,51975035 and 91960203).

摘　　要：Imposing compressive residual stress field around a fastening hole serves as a universal method to enhance the hole fatigue strength in the aircraft assembly filed.Ultrasonic Peening Drilling(UPD)is a recently proposed hybrid hole making process,which can achieve an integration of strengthening and precision-machining with a one-shot-drilling operation.Due to the ironing effect of tool flank surface,UPD introduces large compressive residual stress filed in hole subsurface.In order to reveal the strengthening mechanism of UPD,the influence of ultrasonic vibration and tool dynamic relief angle on ironing coverage rate and its corresponding effect on surface integrity in UPD were analyzed.The experiments were conducted to verify the influence of ironing effect on surface integrity and fatigue behavior of Ti-6Al-4V hole in UPD.The results indicate that the specimen features smaller surface roughness,higher micro-hardness,plastic deformation degree and circumferential compress residual stress under higher ironing coverage rate.The fatigue life increases with the raise of ironing coverage rate,and the fatigue source site in UPD shifts from surface to subsurface comparing with that without vibration assistance.The results demonstrates that a better strengthening effect can be obtained by reasonably controlling the ironing coverage rate in UPD.

关 键 词：Fatigue strength Surface integrity Titanium alloy Tool relief angle Ultrasonic Peening Drilling(UPD) 

分 类 号：V262.4[航空宇航科学与技术—航空宇航制造工程]