Experimental and Mechanism Study of Efficient CFRP
Cutting Based on Continuous Wave Laser and Water Jet Guided Laser Combined Technology
Abstract
With the extensive use of large-thickness carbon fibre reinforced polymer (CFRP) in aerospace, one of the key issues that need to be urgently addressed for thick CFRP is to improve the cutting efficiency. Water jet guided laser (WJGL) technology is one of the desirable approach for CFRP, with the benefits of high depth of cut capability, high processing accuracy and low thermal damage. This paper investigates a the thick CFRP processing method with continuous wave laser and water jet guided laser (CW-WJGL) combined technology, and carries out the research on the influence law of CW-WJGL on the quality and efficiency of CFRP cutting of thick plates. Firstly, a trial study of the CW-WJGL was carried out, and the results showed that the depth of cut capability of the CW-WJGL was significantly improved compared to a single WJGL under single-path reciprocating cutting conditions. By cutting 4 mm thickness CFRP with appropriate quality, the equivalent cutting speed of the WJGL in CW-WJGL was 178.9% higher than that of a single WJGL. Secondly, the high efficiency cutting mechanism of CW-WJGL is illustrated: the advantages of WJGL cutting in the heat affected zone (HAZ) and groove extension together lead to a significant enhancement of the cutting efficiency of CW-WJGL. In conclusion, a CW-WJGL is used to realize high-efficiency machining of 4mm CFRP plates, and the quality of CW-WJGL is consistent with a single WJGL. CFRP CW-WJGL provides technical support for highly efficient processing of large-thickness composites in the aerospace field.
Discussions
1.WJGL offers efficiency advantages in CW HAZ cutting. CFRP CW-WJGL combined processing, cutting equivalent efficiency has been significantly improved. The equivalent cutting efficiency of combined processing was increased by 178.9% compared to WJGL.
2.The CW-WJGL cutting quality is consistent with WJGL. The SEM analysis results show that after CW-WJGL cutting and WJGL cutting, the cutting surface is clean without the accumulation of slag, but there is delamination between the carbon fibres auxiliary layer, carbon fibres breakage, expansion of carbon fibres and the formation of polygonal section morphology.
3.The efficient cutting mechanism of the composite process is revealed. Firstly, WJGL cuts pyrolyzed resin and carbon fibres with significantly improved cutting efficiency. Secondly, the material to be removed is bent and deformed, and the width of the slit increases, which inhibits the formation of the water jet stagnation zone at the bottom of the groove, so that more laser energy is transmitted to the bottom of the groove, and the cutting efficiency is further improved.
