Numerical simulation of effects of cutting edge geometry on machining nickel-based alloy

The commercial finite element software DEFORM-2D was employed to conduct finite element modeling of orthogonal machining of Inconel 718 using multiple honed cutting tools. The cutting edge geometry was described by Sγ and Sα, in which Sγ represented the distance from the transition point between the cutting edge and rake face to the ideal tool tip, while Sα represented the distance from the transition point between the cutting edge and flank face to the ideal tool top. The influences of honed cutting edge geometry and feed on process forces and friction coefficient were investigated, whereas comparison of material flow under conditions of using ideal and honed tools was made. Simulation of microstructure evolution was implemented through the secondary development of DEFORM and predictions of grain size and hardness in machined surface involving chamfered and honed tools were compared. The results show that the hone size and feed have different effects on cutting force Fc and feed force Ff. There exists a critical point of feed affected by the hone size, in which the ratio of process forces μ i. e., Ff/Fc equals 1. Neither Sγ nor Sα shows any explicit influence on chip force FQ and friction coefficient μQ on rake face. Sγ is found to influence material stagnation zone more than Sα while its influence on material separation point is less significant than that of Sα. Moreover, differences are identified according to the results obtained from modeling grain size and hardness with chamfered and honed tools used. © 2020, Central South University Press. All right reserved.