An experimental study on laser drilling and cutting of composite materials for the aerospace industry using excimer and CO2 sources

This paper reports on the results of research which investigated the potential for application of an excimer laser in the field of composite material drilling and cutting, by comparing this technology with that using CO2 sources. In particular, the scope of the work was to check whether the interaction between excimer lasers and composite materials, whose characteristic feature is the absence of thermal transfer, could yield better results than those obtainable with CO2 sources once heat transfer-induced difficulties had been eliminated. The materials selected for the experiments were multilayer composites having an epoxy resin matrix (65% in volume), with aramid fibre (Kevlar), carbon fibre and glass fibre as reinforcing materials, all of considerable interest for the aerospace industry. Optimal operational parameters were identified in relation to each source with a view to obtaining undersize holes or through cuts exhibiting severed areas of good quality. A comparison between the two types of processing carried out show that rims processed by excimer lasers are of better quality—particularly so with Kevlar—whereas the ablation rate is undoubtedly rather low compared with the CO2 technology.