Effects of atomization-based cutting fluid sprays in milling of carbon fiber reinforced polymer composite

Carbon Fiber Reinforced Polymers (CFRP) are considered hard to cut materials, because of the abrasiveness of carbon fibers and the low transverse strength of the composite layers that leads to delimitation under machining forces. The application of cutting fluid is a common way of reducing tool wear and machining forces in machining of metallic materials, yet this solution cannot be applied in machining of CFRP, because moisture damages the structural integrity of the composite workpiece. In this paper, an experimental study is conducted to examine the feasibility and effectiveness of applying atomized cutting fluid in milling of CFRP. In the studied atomization-based method, the cutting fluid is broken down into micrometer size droplets that are sprayed directly into the cutting zone. In the presented study, two types of cutting fluids, general purpose semisynthetic coolant and vegetable oil, are applied by atomization, and their performances in reducing cutting forces, tool wear, surface roughness, and delamination are studied over a range of cutting speeds and feed rate values.