Drilling and helical milling for hole making in multi-material carbon reinforced aluminum laminates

Dissimilar properties of the constituent materials in Fiber Metal Laminates (FMLs) make hole making a demanding task. Improper selection of the process and the process parameters can result in poor surface quality, dimensional inaccuracy, or even failure of the component. The work, therefore, compares the drilling and helical milling process for hole-making in carbon fiber aluminum laminates (CARALL). The comparison was carried out by evaluating the machining forces, chip morphology, machining temperature, surface roughness, hole size, and burr size. The experimental results revealed significantly lower machining forces and machining temperature during helical milling. Utilization of helical milling for hole making resulted in the production of holes within H9 diameter tolerance. Substantial reduction in the surface roughness was noted during helical milling by virtue of the discontinuous chips generated during the process. Furthermore, holes processed using helical milling showed relatively smaller-sized burrs in comparison to the drilling process. Overall, the initial evaluation exhibits the positive capability of helical milling for hole-making in CARALL FMLs.