Fundamental estimation method of drilling characteristics using carbon fiber reinforced thermoplastics with unidirectional fiber

This study presents a fundamental estimation method of drilling characteristics of carbon fiber reinforced thermoplastics (CFRTPs). To simplify the evaluation of the relation between the drill rotation angle and the fiber orientation, a unidirectional CFRTP was used workpiece. The waveform behavior of the thrust force during drill rotation and the quality of the drilled hole entrance were investigated. The thrust force reached its maximum during drill rotation when the tangential direction of the rotating peripheral corner edge of the drill coincided with the fiber orientation of the workpiece. The relationship between the drill rotation angle with respect to the fiber orientation and the generated burrs and chippings on the edge of the drilled hole entrance were observed.