Atarsia, A., "Axial and Orbital Drilling of Thick Stacks for New Aircraft Assembly Process," SAE Int. J. Aerosp. 6(2):540-544, 2013, doi:10.4271/2013-01-2226.
This technical paper deals with design and manufacture of axial and orbital cutters for drilling large diameters holes in Carbon Fiber Reinforced Plastics (CFRP) / Titanium (TA6V) thick stack by means of an Automated Drilling Unit fixed on a drilling template. Creating tools that drill such stacked holes in a single operation is particularly difficult. The common strategies for tool designs designated to cutting composites stacked with metals as titanium include uncoated carbide, tools with a diamond coating applied by chemical vapor deposition (CVD). It is also question of what kind of drilling process should we use to achieve larger holes in minimum time. Therefore, axial drilling process with pilot, drill and ream steps find a competitor drilling process named orbital drilling which can achieve both operations in one step allowing then, burrless, free delamination, small and easy removable chips all with one tool being able to achieve different hole sizes. The present study compares the quality of drilled holes in term of both materials hole diameters, exit burr and cycle time which become a decision gate for the process choice.