An investigation on cutting forces and hole quality on drilling of multimaterial. Statistical and experimental analysis
Résumé
The thrust force and surface roughness of plain carbide drill (K20) with drill parameters (drill diameter, spindle speed and feed rate) in drilling carbon fibre reinforced plastic (CFRP) laminate/aluminium (Grade 2024) stack was experimentally investigated in this study. A L27 orthogonal array and signal-to-noise (S/N) were employed to analyze the effect of drill parameters. Using Taguchi method for design of a robust experiment, the interactions among factors are also investigated. The analysis of variance (ANOVA) shows that the feed rate and drill diameter are the most significant parameters to the overall performance while drilling CFRP/al stack. Nano-coated tools used for drilling made of tungsten carbide; show that the shape and the size of the chips are strongly influenced by the feed rate. The thrust force generated during drilling of the composite materials with coated drills is 10% to 15% less when compared with the thrust force generated during drilling with uncoated drills. Moreover, the thrusts forces in the aluminium are 50% less with coated drills compared to thrust force generated without coated drills. Apart from the forces the nanocoated drills make it possible to carry out holes in the composite plates and aluminium with surface roughness 50% lesser compared with those obtained with uncoated tools.