Machining of composite materials

In this chapter, an overview of the main issues concerning drilling of polymer matrix fibrous composite materials is presented. These materials are widely used for parts manufacturing in the aerospace industry due to their high specific mechanical properties and low weight, and require extensive drilling processes, for e.g. joining. A proper optimization of the drilling process can substantially improve parts quality, often affected by diverse faults generated during the process. As several parameters are involved in FRP composites drilling, and complex phenomena occur, which are completely different from metal cutting, such optimization is a challenging task. To examine the relevant issues, the influence of tool geometry and technological parameters on thrust force, torque and tool wear are discussed, as well as their role in delamination. These aspects are illustrated with particular reference to drilling of carbon fiber reinforced polymer (CFRP) composites, which are widely employed in the aerospace industry.