A new cutting force prediction method in ball-end milling based on material properties for difficult-to-machine materials

As the machining process is remarkably influenced by the cutting force, its prediction is of great significance. For most of the commonly used cutting force prediction models, they are no longer applicable once the workpiece material is altered. Consequently, a new ball-end milling force prediction method with the consideration of the workpiece material properties is presented in this study for difficult-to-machine materials in high-speed milling. Based on differential and oblique cutting mechanisms, the metal cutting process in this method is taken as the linear superposition of a series of differential oblique cutting processes. With laboring the force-loading status of rake face, the yield strength, the heat conductivity, and the plasticity of the material which are the most important factors to influence cutting force are involved as the input elements. Furthermore, the interaction between material properties and machining conditions is also introduced to broadened the scope of applications of this method. In accordance with specific needs, an inverse method using the average cutting force of a single disk after cutting edge discretization is proposed to obtain the specific coefficients, and the cutter engagement is determined by Z-map method. Finally, the comparison between the simulated result and the experimental result confirms the effectiveness of the presented method for different difficult-to-machine materials in high-speed milling based on slot milling and curved surface milling.