Influence of cutting parameters on tool wear and hole quality in composite aerospace components drilling

Abstract Composite Fiber Reinforced Plastics (CFRP) are characterized by their outstanding mechanical properties combined with reduced density and good resistance to corrosion and fatigue which make them suitable for aerospace components. During assembly procedures, one shoot drilling operations, usually including countersinking cycle, are required to minimize positional errors, enhance tight tolerances and reduce process time. Countersink drill bits were tested on CFRP test specimens, representative of aircraft components. Along testing, tool wear was monitored with an optical microscope to track its evolution and determine the dominant wear mechanism. On the other hand, hole quality was evaluated since tool life criterion is based on the assessment of machined surface quality. The influence of cutting speed and feed was analyzed with the objective of looking for extended tool life and more productive cutting parameters. The information gathered from monitoring tool wear and inspecting hole quality can be used for the enhancement of CFRP drilling and the improvement of the manufacturing process competitiveness, in terms of production cost and time.