Performance of micro end milling force prediction on Aluminum 6061-T6 with 3D FE simulation

Micro-milling is a rather complicated process to simulate due to the complexities involved, such as the geometrical, mechanical, tribological, thermal and chemical aspects. They all lead to the generation of cutting forces and consequent material removal in micro scale which have some straight difference in respect to macro cutting. So far, not many 3D FEM have been presented along with their experimental validation results in micro milling. This study discusses the performance of 3D force prediction of a Finite Element model of micro end-mill cutting on Aluminum 6061-T6, implemented in AdvantEdge®. FE shows some important advantages, i.e. can easily deal with any kind of tool geometry and any side effects affecting chip formation such as thermal aspects and material properties changes. On the other hand, due to the small chip size of micro milling, extremely fine meshes and related automatic remeshing techniques are required thus increasing the computation efforts: the simulation of even a partial cutter engagement requires several hours/days of computation with the available power on to-date computing servers. In order to evaluate whether these efforts are worthy, compared to other modelling techniques, the performance of the FEM prediction were compared with the performance of a state-of-art mechanistic model, capable of including minimum chip thickness aspects as well effective rake angle effects and capable of providing force prediction with less computational time. The simulated cutting forces with the two models are then compared with experimental results and a supporting discussion is provided. Tolerable correlations between the forces profile shapes were observed. In terms of force magnitude, the predictions were overestimating the real values, also considering the results provided by the mechanistic model and to cope with that some further development area of the model are identified.