An Experimental Study Investigating the Influence of the Number of Blades in a Cutter Used in Axial Cutting of AA6061-T6 and T4 Round Tubes

Quasi-static axial cutting of AA6061-T6 and T4 round extrusions were completed using a specially designed cutter with multiple blades. The round specimens had a length of 200 mm, a nominal outer diameter of 50.8 mm, and a wall thickness of 3.175 mm or 1.587 mm. Four different cutters, constructed from heat-treated 4140 steel, having 3, 4, 5 and 6 blades on each cutter with a nominal tip width of 1.0 mm were used to penetrate through the round extrusions. A clean cutting mode was observed for the AA6061-T6 and T4 extrusions with wall thickness of 3.175 mm with an almost constant steady state cutting force. A braided cutting mode was observed for extrusions with both tempers with wall thickness of 1.587 mm, which resulted in a slightly oscillating steady state cutting force. For all extrusions with a wall thickness of 3.175 mm, the steady state cutting force increased with an increase in the number of cutter blades. To better understand the influence of the number of cutter blades on the steady state cutting force and energy absorption characteristics of extrusions, a numerical model was developed and simulated using LS-DYNA® employing an Eulerian finite element formulation to overcome numerical instabilities associated with massive mesh distortion. Good predictive capabilities of the developed numerical model were observed and were important towards the understanding of the contribution of deformation mechanisms and friction towards the force/displacement response of the extrusions in the cutting deformation mode.