Fibre laser cutting of carbon fibre reinforced polymeric composites

Owing to the increasing industrial demand for carbon fibre-reinforced polymer composite materials, the interest in effective machining technology grows. The current carbon fibre-reinforced polymer machining technique is dominated by mechanical milling, which often results in high tooling cost and some defects in the machined materials. The exploration of alternative machining techniques is becoming more important. Laser machining as an advanced non-contact technique can potentially improve the machining of carbon fibre-reinforced polymers. However, thermal damages to the machined materials owing to the inhomogeneous, anisotropic and heterogeneous features of these materials have been prohibiting the application of laser machining in industrial scale for carbon fibre-reinforced polymers. In this article, an investigation on the basic characteristics of high-power single-mode ytterbium-doped fibre laser machining of carbon fibre-reinforced polymer is reported. Statistical analysis was performed for the optimisation of the process parameters in single-pass cutting. Furthermore, quality improvement was achieved by the use of multiple-pass cutting technique, which was found to be effective to minimise delamination at low power level and high scanning speeds.