Influence of the Double Cone Drill Geometry on the Holes Quality during Drilling Multi-Stack Made of CFRP/Al

Abstract

Abstract-In this paper, experimental study on drilling of multi-material made of CFRP laminate sandwiched with aluminum part has been carried out. These tests have been conducted using carbide drills (K20) to study the influence of spindle speed, feed rate and lip length of the double cone drill on cutting forces and holes quality. From the experimental study it was found that the double cone drills used for the experimental analysis encountered less thrust force compared to the standard twist drill. In addition the quality of the holes after drilling were evaluated, and found that no delamination (entry and exit of the hole of the composite part) even at higher feed rate (> to 0.1 mm/rev). From the SEM observation it was noticed that, after machining with standard twist drill, several damaged areas were observed on the wall of the holes.