An analytical model to predict interlayer burr size following drilling of CFRP-metallic stack assemblies

A novel analytical model to describe entrance burr formation when drilling ductile metals as a function of tool geometry (point/helix angles, diameter), operating parameters (cutting speed, feed rate) and workpiece material properties, was initially formulated. The model was further developed to account for interlayer burr dimensions when drilling CFRP-metallic stack arrangements. Data from validation trials performed on Ti–6Al–4V, AA7010 and AA2024 workpieces together with their associated CFRP stack assemblies over 4 different combinations of cutting speed and feed rate showed that the predicted sizes of entrance and interlayer burrs were all accurate to within 20% of the experimentally measured results.