Influence of consolidation process on the drilling performance and machinability of PIXA-M and PEEK thermoplastic composites

In this paper, the drilling performance of two composite systems, namely graphite-PIXA-M (PIXA-M) and graphite-PEEK (PEEK) induction heat-pressed thermoplastic composites, are compared with their counterpart from autoclave processing. Machinability is evaluated in terms of drilling forces and hole quality. Hole quality characteristics are evaluated in terms of geometric accuracy and surface finish. The experimental observations discuss unique chip characteristics during drilling both autoclaved and induction heat-pressed thermoplastic composites. The mechanism of material removal in drilling of thermoplastic composites is investigated through the further calculation of the specific cutting energy. The induction-processed composite material produced equivalent or better holes than the autoclave-processed composites although it required larger cutting force magnitudes and protruded fibers on the bottom ply are produced. The induction heat press may be a viable alternative for the processing of thermoplastic composites in terms of drilling performance.