Implementation of material model based on the microstructure changes for simulation of machining process

Generally, microstructural changes have been neglected for the material models used for simulation of chip formation process. This event leads to limitation in precision of numerical results compared to what happens in reality. For this purpose, in the present study the effect of microstructure changes in machining process of Inconel 718 super alloy was taken into account by development of multi-step user-subroutine in Finite Element Model (FEM). Firstly, microstructure change was modeled using the Dynamic Recrystallization (DRX) and critical strain criterion. After that, a modified material model was presented and grain size variation was incorporated into the material model for each step and each element during the simulation. At the end, effectiveness and performance of the new material model was successfully evaluated by comparison with corresponding experiments at the different machining conditions. The results indicate that, implementation of microstructure changes in material model plays effective role for simulation of more realistic behavior of material and consequently improvement of numerical results machining.