An Analysis of the Circularity of the Holes in the Drilling of Basalt Fiber Reinforced Laminates

Abstract

The application of basalt fiber reinforced composites has increased in recent years. However, its behavior during machining processes remains to be studied in depth, as drilling operations. The objective of this paper is to analyze the circularity of the holes at the exit of the drill in these composites. The laminates were obtained through basalt fiber fabrics and epoxy resin, with application of pressure and heat to achieve the final prepregs. These basalt fiber-epoxy laminates were used in experimental tests and drilled under different cutting conditions and three types of drill bits. The quality of the holes was measured through the outlet diameters, and thus determining the circularity of the holes. A three coordinate measuring machine was used in this process. Moreover a General Linear Model has been estimated, obtaining a coefficient of determination of 86.5%. The results have indicated that the drill bit type and its rotation speed are significant factors. Moreover, the outcomes have allowed to select a suitable type of drill bit, to limit the cutting conditions, and to identify the influential points, conditions that have provide undersized and oversized diameters.