Fiber laser cutting of CFRP laminates with single- and multi-pass strategy: A feasibility study

Abstract

Experimental data is presented relating to hole quality and feasibility studies when using continuous wave (CW) fiber laser to cut CFRP laminates (6.0 mm diameter hole) with single- and multi-pass strategy. The effect of typical processing parameters including laser power and cutting speed on thermal defect was also investigated. The statistical significance of individual cutting parameters was determined using main effects plot together with ANOVA analysis. Three methods were proposed to characterize HAZ based on the feature of thermal defect. According to statistical analysis, both cutting speed and laser power were significant with respect to HAZ (recorded at hole exit). The minimal value of HAZ was recorded with laser power of 650 W and cutting speed of 1100 mm/min. Energy per unit length (El) should be set above 40 J/mm to ensure cutting through CFRP laminates using fiber laser in high efficient machining process. Multi-pass strategy was investigated without setting pause/break time between each pass in order to increase cutting efficiency. Results showed limited improvement in terms of the level of HAZ even with cutting speed up to 10,000 mm/min, while machining time was significantly reduced to cut 6.0 mm diameter hole compared with single-pass strategy. For machining small holes with diameter down to 2.0 mm, high power fiber laser was not preferred due to severe thermal defect observed at hole entry and exit.