A new model for the prediction of cutting forces in micro-end-milling operations

In this work an analytical forces model for real micro-end-milling is developed by regarding the main factors which have influence on the process. The run-out or eccentric deviation of the tool path is taken into account as well as the tool deflection. A linear equation system has to be solved to obtain the forces, so it requires a low computational cost. Size effect is also considered since the chip thickness is comparable to the edge radius and therefore there is chip removal only when it is higher than a certain value. This phenomenon causes variation in the entry and exit angles of the tool in the workpiece. These factors have already been studied in conventional milling. However, since they have not been yet considered for micromilling, the validity of mechanistic models is limited. The model has been developed for two different types of side micromilling: up milling and down milling. Experimental results carried out on Steel and Aluminum show a good correlation with the model. The forces model proposed in this work can be used in a process monitoring in real time as well as in adaptive control of the process.

► Influence of size effect, run-out and tool deflection in micromilling is assessed.
► Tool deflection distorts edge paths according to the elastic behavior of the tool.
► Formulation of forces values for the periods in which only an edge cut is made.
► Entry and exit angles are calculated taking into account the size effect.
► Simulations according to the model show good fitting to experimental results.