Study on the Machinability of Glass, Carbon and Aramid Fiber Reinforced Plastics in Drilling and Secondary Drilling Operations

Composite materials are usually subjected to machining processes, especially when they are used to for the aviation and automotive industries. Apart from side surface milling and face milling, these materials are subjected to machining to make holes and countersinking holes, cuts of complex shape, recesses, and grooves. One of the many machining methods for polymer composites is drilling. The accuracy of a drilled hole is very important for operational reasons, because it has impact on the quality and strength of the connection between polymer composite elements and structural elements. This paper shows the results of a study investigating the impact of drilling and secondary drilling as well as technological drilling parameters on the maximum feed force, surface roughness and hole quality. Holes were drilled in glass, carbon and aramid fiber reinforced plastics. The study has shown that the highest maximum feed force occurs when drilling in aramid fiber reinforced plastic. The lowest values of the maximum feed force were obtained when drilling in glass fiber reinforced plastic. The influence of drilling parameters on surface roughness during drilling holes in composite materials was also determined. The highest values of roughness parameters were obtained in the machining of aramid fiber reinforced plastic, while the lowest roughness parameters were obtained on the hole surface when drilling in carbon fiber reinforced plastic.