Investigation on cutting of CFRP composite by nanosecond short-pulsed laser with rotary drilling method

In the present research, the nanosecond short-pulsed laser with rotary drilling method was designed to process carbon fiber-reinforced polymer (CFRP) composite plate. The hole dimension, surface morphology, heat-affected zone (HAZ), and mechanical properties were analyzed. The results reveal that the CFRP composite plate could be rapidly drilled with highly qualified processing surface by the nanosecond short-pulsed laser with rotary drilling method. The figures such as circle, square, triangle, and regular hexagon could be processed with minimum hole diameter of 0.1 mm. The changing of laser scanning speed and laser power could result in the variation in diameter of hole entrance and exit, which fluctuates in scope of 35 mu m. The calculated biggest taper angle is about 0.43 degrees, but the smallest taper angle is about 0.12 degrees. The laser drilling on CFPR composite decreases the tensile strength by about 9%, which should be ascribed to the damage of continuous carbon fiber, but it is still acceptable. The nanosecond short-pulsed laser with rotary drilling method generates a small HAZ on hole entrance but almost no HAZ in hole exit. The surface roughness of laser processed CFRP ranges from 2.925 to 4.226 mu m. Comparatively, the laser scanning speed between 800 and 1,000 mm/s and laser power around 28 W would be the optimal choice, which could realize the best balance between surface quality and efficiency.