Comparative study of tool wear and machining quality in drilling of thermoplastic CF/PEEK and thermoset CF/epoxy composites

Abstract

Carbon fiber reinforced polyetheretherketone (CF/PEEK) is widely used in the aviation industry due to its high performance and ease of recycling and repair. The PEEK matrix is easy to soften when heated, which causes serious tool wear and affects machining quality and efficiency. However, tool wear mechanisms in drilling CF/PEEK composites are still unclear and there is a lack of research on the relationship between tool wear and drilling performance. This is the first study presents a comprehensive comparative analysis of tool wear mechanisms and their influence on drilling temperature, cutting forces, and hole-making quality between thermoplastic CF/PEEK and thermoset CF/epoxy composites. The results indicate that the primary wear mechanism for drilling thermoset CF/epoxy is abrasive wear, while adhesion wear dominates in thermoplastic CF/PEEK. The drilling thrust force and temperature in CF/PEEK exhibit significantly higher sensitivity to the progression of tool wear. As the number of drilled holes increases, the hole-making quality of CF/PEEK exhibits a more pronounced deterioration compared to that of CF/epoxy. This study provides valuable insights into the distinct wear mechanisms and performance differences between thermoplastic and thermoset composites during drilling processes.