A feasible strategy to produce quality holes using temperature-assisted drilling on CFRP

Drilling of carbon fibre-reinforced polymer composite (CFRP) material is an essential machining process in aerospace structural applications to fix/bolt holes for assembling parts. Here, producing quality holes is essential to avoid rejection of parts and it remains a great challenge to overcome damages while drilling. Monitoring the optimal drilling parameters and environmental conditions is a viable strategy to reduce the drilling-induced damages in CFRP. In this experimental investigation, a comparative study is made between chilled air-, dry air- and hot air-assisted drilling on UD-CFRP material, and the effect of drilling parameters is outlined. The thrust force, delamination, burr formation, surface roughness and surface damages of the drilled hole are analysed at different environments and machining conditions. The experimental results indicated that the drilling at the hot air environmental condition reduces the thrust force and delamination factor at low feed rate. At the same time, a higher burr removal rate and increased surface finish were obtained at the chilled air condition when compared with other environmental conditions.