Study on the tool-chip friction coefficient of bottom edge in high-speed internal cooling spiral milling hole

Abstract

The main focus of this work is the effect of the third body on the friction coefficient of the bottom edge tool-chip in spiral milling with internal cooling at high speeds. The maximum pressure of the tool-chip contact and the tool-chip friction factor of the bottom edge are estimated by evaluating the helical milling principle and milling experiments, and the Hertz-Mindlin with bonding discrete element model（DEM）is established and corrected. The friction coefficient of the bottom edge tool-chip in the process of high-speed internal cooling milling is discovered to decrease with an increase in the number of third bodies by examining the discrete element model and the morphology of the machined surface and the bottom edge. The third body increases as spindle speed increases but decreases as pitch increases. The research results provide a reference for the study of tool - chip friction coefficient in high-speed internal cooling helical milling.