A comparative study on conventional drilling and ultrasonic vibration-assisted drilling of CF/PEEK

While thermoplastic carbon fiber-reinforced polyetheretherketone (CF/PEEK) are gaining prominence in manufacturing high-end aerospace components, their drilling-induced damage remains a challenge. Although ultrasonic vibration-assisted drilling (UVAD) has been explored for thermoplastics, existing studies report conflicting thermal effects and lack comprehensive hole quality assessment. This paper addresses these gaps by systematically comparing UVAD and conventional drilling (CD) of CF/PEEK. Kinematic analysis clarifies the fundamental cutting differences between CD and UVAD. Experimental results reveal that the effectiveness of UVAD is highly dependent on spindle speed: at low spindle speeds, the thrust force and drilling temperature in UVAD can be reduced by up to 19.1% and 26.7%, respectively. Crucially, under optimized low-speed parameters, UVAD substantially minimizes hole damage and improves dimensional accuracy compared to CD. This study resolves the apparent contradiction in existing literature by identifying spindle speed as a key determinant of the effect of UVAD. The findings provide direct practical guidance for selecting low-speed UVAD parameters in aerospace manufacturing of CF/PEEK components.