Investigating the Impact of Drill Point Angles on the Drilling Behavior of Date Palm Biocomposites: Experimental, ANN, and Taguchi Modeling

This research aims to assess the mechanical performance and analyze the effects of drilling parameters as a function of spindle speed (500, 1000, and 1500 rpm), feed rate (50, 100, and 150 mm/min), and point angles of drill bits (85°, 115°, and 135°) on eventually circularity and cylindricity errors in drilling (Palm Fiber Powder/Epoxy) biocomposites (PFPEs). Geometric errors, specifically circular and cylindrical deviations, were assessed on 27 pieces, revealing that an increase in spindle speed correlated with a decrease in circularity error and an increase in cylindrical error. Conversely, higher feed rates were associated with an increase in both errors. Notably, the drill with a 115°-point angle demonstrated superior performance compared to other drills. Optimal drilling quality was achieved using the HSS-SUPER drill with a 115°-point angle, operating at a spindle speed of 500 rpm and a feed rate of 100 mm/min. The study utilized artificial neural networks (ANN) and the Taguchi method to validate the experimental findings and predict the drilling behavior of PFPEs under various cutting conditions. ANN models demonstrated higher predictive accuracy, with correlation coefficients of approximately 96.61% and 89.64% for circularity and cylindricity errors, respectively, compared to 78.33% and 79.22% for the Taguchi model.