Investigation of Damage Reduction When Dry-Drilling Aramid Fiber-Reinforced Plastics Based on a Three-Point Step Drill

Abstract

Aramid fiber-reinforced plastic (AFRP) is widely used in bullet-proof and armor structures, and is difficult to drill because of the high-toughness aramid fibers with ductile fracturing—differently from carbon fiber. Therefore, drilling quality cannot be ensured by the drilling used for carbon fiber-reinforced plastic, and frequently, delamination and burrs occur in the drilling process. This article first established a two-dimensional cutting model for analyzing the fiber deformation and material interface cracking. According to the model, reducing the thrust force and the radial force of the edge on the fibers is an effective way to reduce the fiber deformation, and a three-point step drill is proposed further. Comparative experiments were carried out among twist drilling, candle core drilling and three-point step drilling under three drilling parameters. The results show that the three-point step drill changed the traditional cutting behavior on the drill-exit material into a compound process. Finally, the AFRP was cut effectively with the novel drill with a small thrust force, and the delamination and “burrs area” were reduced through different drilling parameters. In summary, the three-point step drill can drill the AFRP without delamination and burrs with 0.02 mm/rev, which provides a new solution of cost-effective production for AFRP manufacturers.

Determination of Processing Precision of Hole in Industrial Plastic Materials

“…In specialized literature, several studies addressing this subject have been located. Among the most relevant is the research of [1], which studied aramid fiber-reinforced plastic. This material is used in bulletproof and armored structures.…”

“…Among the most relevant is the research of [ 1 ], which studied aramid fiber-reinforced plastic. This material is used in bulletproof and armored structures.…”

“…The experimental results indicated that the most significant effect was that the drill type influenced both the delamination factor and the surface roughness. All these articles [ 1 , 2 , 3 , 4 , 5 ] provide comprehensive and available information on the performance of tools for drilling aramid fiber-reinforced plastics, which can help guide process optimizations to achieve the desired hole quality.…”

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

“…Due to the difficulties involved in machining these materials, there are few studies on these materials [44,45]. Previous studies on aramid fiber reinforced plastics investigated the influence of feed on cutting force and hole quality [46,47]. The investigation of the geometrical structure of surface in various materials makes it possible to understand phenomena and factors influencing its shape and parameters [48][49][50][51][52][53][54][55].…”

Estudio de la fuerza de avance y la circularidad de los agujeros en el taladrado criogénico de materiales compuestos con aramida

“…Los materiales compuestos con fibras de aramida o fibras kevlar son difíciles de mecanizar, por tanto, el objetivo es encontrar un procedimiento que consiga mejores resultados respecto a las fuerzas necesarias y la calidad de los agujeros del taladrado. En los resultados de las variables durante y después del taladrado influyen muchos factores, comenzando por las brocas, con lo que se obtienen resultados muy diversos [8][9]. La literatura académica muestra algunas alternativas, como el taladrado por láser [10] y este trabajo se centra en otra opción como es el mecanizado criogénico con nitrógeno líquido, con el objetivo de determinar su viabilidad en compuestos con fibras de aramida mediante el análisis de las fuerzas de avance, el diámetro de los agujeros taladrados y la rugosidad de sus paredes.…”