Simulation of micro-milling Inconel 718 considering scale effect

To study the scale effect during micro-milling process, we establish a modified Johnson-Cook (JC) constitutive model to describe the strengthening behavior of materials on microscale based on the theory of strain gradient plasticity. The VUMAT constitutive subroutine of Inconel 718 is programmed. The radius of the tool edge and its influence on the rake angle are considered. Based on the modified JC constitutive equation, the simulation of micro-milling Inconel 718 process is achieved. The micro-milling Inconel 718 experiments are conducted. The accuracy of the simulation of micro-milling Inconel 718 process considering scale effect is verified by comparing cutting force from experiments with simulation outputs based on the traditional as well as modified JC constitutive equation. It is proved that the simulation outputs of the micro-milling process based on the modified JC constitutive equation are more consistent with the experimental results.