Measurement and analysis of thrust force and delamination in drilling glass fiber reinforced polypropylene composites using different drills

Abstract

Fiber Reinforced Plastic (FRP) composites are widely used in various engineering fields and applications. FRPs were initially fabricated using thermoset polymers owing to ease of manufacturing. Of late, FRP based thermoplastics is gaining importance due to various factors such as impact resistance, recycling, and an absence of any chemical reaction. In the present investigation, Glass Fiber Reinforced Plastic (GFRP) laminates of woven glass fabric reinforcements with Polypropylene (PP) thermoplastic matrix is manufactured using film stacking technique. To analyze the performance in machining, drilling studies are carried out using a 6 mm diameter twist drill of High Speed Steel (HSS) drill, tipped carbide and solid carbide drill. The drilling experiments are conducted on a CNC Vertical Machining Centre (VMC) to measure and assess the drilling induced thrust force and the respective exit delamination. The drill spindle speed and feed rate are considered as process parameters. To correlate the process parameters with responses, the regression models are developed. The results indicate that the most significant control parameter for process responses and also it shows the developed regression models are highly reliable. The influence of drill materials on the performance of the responses is also discussed in detail.