An experimental investigation of the effect of coatings and cutting parameters on the dry drilling performance of aluminium alloys

As a result of the need to automate assembly in the aircraft industry, along with economic and ecological reasons, industry and research institutions have been pushed to develop dry drilling for aluminium alloys to eliminate the need for cooling fluids. The main difficulties in dry drilling are accelerated tool wear due to workpiece material adhesion on the tool and the formation of bigger-sized burrs. This paper describes an experimental research study on machinability in the dry drilling of aluminium alloys and on the potential of the new design of tools and coatings. Dry drilling tests were performed using uncoated drills and two different coatings produced by means of an arc evaporation PVD process. Experiments consisted of machining with a 10-mm diameter three-edged drill to produce 25-mm deep holes. Tool wear evolution and burr size were analysed, as well as the impact of the process parameters on torque, power, feed force and tool temperature.