Experimental investigation on robotic high and low frequency compound vibration-assisted drilling of CFRP/titanium alloy laminated structures

To mitigate the high drilling temperatures and extensive machining damage associated with CFRP/titanium alloy laminated materials, a new robotic high and low frequency compound vibration-assisted drilling method has been developed. To assess the effectiveness of this process, a comparative experimental study was performed, comparing four machining techniques: conventional robot drilling, robotic high-frequency vibration drilling, robotic low-frequency vibration drilling, and robotic high and low frequency compound vibration-assisted drilling. The study evaluated drilling force, titanium alloy cutting temperature, titanium alloy chip morphology, the quality of CFRP holes, and the quality of Ti holes walls. The experimental results show that among the four processing methods, the high and low frequency compound vibration-assisted drilling by the robot can effectively reduce the axial force during drilling; the high and low frequency compound vibration-assisted drilling by the robot significantly reduces the cutting temperature of titanium alloy, with a maximum reduction of 31.25% compared to conventional robot drilling; the titanium alloy chips produced by the robot's high and low frequency compound vibrationassisted drilling are fan-shaped and the smallest in size; the high and low frequency compound vibration-assisted drilling by the robot significantly improves the CFRP hole edge damage and hole wall quality at low feed rates; the high and low frequency compound vibrationassisted drilling by the robot can significantly improves the quality of titanium alloy hole walls at low feed rates. Moreover, this improvement remains evident as the feed rate increases.