The Effect of Drilling Parameters on the Hole Quality of Hybrid Fiber-Reinforced Epoxy Composite

In this work, hybrid fiber-reinforced epoxy composite had been developed by using woven banana fiber and woven glass fiber as reinforcements. Laminated composite sample was developed by using hand layup method. Glass fiber was kept
as top layer, and banana fiber was kept as bottom layer with the arrangement of G-B-G-B. Drilling is one of the most common and critical machining operations during the assembly operation in manufacturing. In this work, the effect of drilling parameters on the quality of the hole and delamination was studied. Three different drill speeds and feed rates were used in this study. The machining was done by using a twist drill of diameter 8 mm, and the drilling was performed at the speeds of 700, 1400 and 2100 rpm. The feed rate was kept at 0.05, 0.12 and 0.20 mm/rev. The
drilled holes were scanned in a high-resolution scanner, and digital image processing was further used to compute the hole dimensions. The details of the pixel values at
the entry and exit were measured digitally, and subsequently, the pixel values were used to determine the extent of damage occurred due to the drilling operation. A
two-dimensional array of hole dimension with respect to the feed rate and speed was obtained from the experimental results. Finally, ANOVA technique was used to determine the most influencing drilling parameter to get better hole quality. The experimental results indicated that the damage due to machining was greater at the exit than the damage at the entry. Also, ANOVA technique showed that the drilled
hole quality depends on the drilling speed and feed rate, but the feed rate is the most significant parameter than the cutting speed.