Ablation-cooling effect during nanosecond laser precision machining of CFRP

Abstract

Heat-affected zone (HAZ) in laser machining of carbon fiber reinforced plastic (CFRP) is an important factor affecting the assembly and service performance of CFRP. The ablation-cooling effect induced by nanosecond laser can be used to control HAZ of CFRP and improve the machining efficiency simultaneously. In this paper, the influence of key parameters such as peak power density, pulse width and repetition frequency on the formation mechanism of HAZ and the conditions for ablation-cooling are studied based on simulation and experiment. The simulation results show that ablation-cooling is more likely to occur at the high peak power density and high repetition frequency. When the peak power density is ≥10⁸ W/cm², the ablation-cooling effect plays a leading role, and the removal amount of fiber and resin is the same, so that the no HAZ processing is realized. The pulse width affects the width of HAZ through the ablation mechanism. The experimental results show that when the peak power density is greater than 10⁸ W/cm², the ablation-cooling effect effectively reduces HAZ and increases the removal amount, which is consistent with the simulation law.