The study on dynamic properties of monolithic ball end mills with various slenderness

¹ Poznan University of Technology, Faculty of Mechanical Engineering and Management, Institute of Mechanical Technology, Poznan, Poland
² Opole University of Technology, 76 Prószkowska St., Opole 45-758, Poland
³ University of Zielona Gora, 4 Prof. Z. Szafrana street, 65-516 Zielona Gora, Poland

^⁎ Corresponding author: szymon.wojciechowski@put.poznan.pl

Abstract

The reliable determination of modal mass, damping and stiffness coefficient (modal parameters) for the particular machine-toolholder-tool system is essential for the accurate estimation of vibrations, stability and thus the machined surface finish formed during the milling process. Therefore, this paper focuses on the analysis of ball end mill's dynamical properties. The tools investigated during this study are monolithic ball end mills with different slenderness values, made of coated cemented carbide. These kinds of tools are very often applied during the precise milling of curvilinear surfaces. The research program included the impulse test carried out for the investigated tools clamped in the hydraulic toolholder. The obtained modal parameters were further applied in the developed tool's instantaneous deflection model, in order to estimate the tool's working part vibrations during precise milling. The application of the proposed dynamics model involved also the determination of instantaneous cutting forces on the basis of the mechanistic approach. The research revealed that ball end mill's slenderness can be considered as an important milling dynamics and machined surface quality indicator.