Micro milling force prediction of arc thin-walled parts considering dual flexibility coupling deformation

The prediction of micro milling forces in difficult-to-machine materials such as titanium alloys, which have small dimensions and arc-thin-walled features, has become a major challenge due to coupling effects of multi-physics fields. This problem has become a key bottleneck in the development of aerospace, biomedical, and other fields. This study focuses on titanium alloy arc-thin-walled parts and develops a micro milling force prediction model that considers the dual flexible coupling deformation and geometric features of arc-thin-walled parts in the process of micro milling. Firstly, a micro milling force theoretical model is established based on the instantaneous cutter position angle and instantaneous uncut chip thickness. Secondly, the detailed geometric analysis is conducted to calculate the entry and exit angles and instantaneous uncut chip thickness considering the micro milling path characteristics. Subsequently, the Euler beam and Timoshenko beam are assumed based on the characteristics of the cutter and workpiece structure, as well as the force situations. The deflection deformation values are calculated by solving unit stiffness matrix. The coupling deflection deformation is introduced into the micro milling force prediction model by an iterative algorithm, and this improves the instantaneous uncut chip thickness model. Finally, the micro milling force data is obtained through arc micro milling experiments, and the coefficient of micro milling force is identified. The reliability and accuracy of the micro milling force prediction model are verified through experiments, of which the prediction error range is 9.005~12.427%. The proposed model and methodology have practical significance and provide a basis for optimizing micro milling processes and promoting the development of related fields.