A Mechanistic Model of Cutting Forces in Micro-End-Milling With Cutting-Condition-Independent Cutting Force Coefficients

Abstract

Complex three-dimensional miniature components are needed in a wide range of industrial applications from aerospace to biomedicine. Such products can be effectively produced by micro-end-milling processes that are capable of accurately producing high aspect ratio features and parts. This paper presents a mechanistic cutting force model for the precise prediction of the cutting forces in micro-end-milling under various cutting conditions. In order to account for the actual physical phenomena at the edge of the tool, the components of the cutting force vector are determined based on the newly introduced concept of the partial effective rake angle. The proposed model also uses instantaneous cutting force coefficients that are independent of the end-milling cutting conditions. These cutting force coefficients, determined from measured cutting forces, reflect the influence of the majority of cutting mechanisms involved in micro-end-milling including the minimum chip-thickness effect. The comparison of the predicted and measured cutting forces has shown that the proposed method provides very accurate results.

An improved cutting force model for micro milling considering machining dynamics

“…Gye et al [14] obtained the deformation of the micro tool based on the cutting force predicted; however, the influence of the deformation of the micro tool on the cutting force was not studied. Wang et al [15] proposed a micro milling cutting force model considering the minimum chip thickness effect, cutter deflection and spindle runout. Based on the proposed cutting force model, a method to determine the optimal micro milling parameters was developed.…”

Modelling the cutting forces in micro-end-milling using a hybrid approach

“…Zaman [13] developed a three-dimensional analytical cutting model for micro-endmilling operation, which determines the theoretical chip area at any specific angular position of the tool cutting edge by considering the geometry of the path of the cutting edge and relates this with tangential cutting force. Lee [14] developed a mechanistic cutting force modeling in micro-end-milling with cutting-condition-independent cutting force coefficients. Lai [15] presented an analytical micro scale milling force model based on the FE simulations using the cutting principles and the slip-line theory.…”

Applicability of an orthogonal cutting slip-line field model for the microscale

“…The present paper has been focused on the Waldorf's slip-line field model [9][10] applied to typical microcutting parameters in both its original version and a modified version implementing the effective rake angle [4]. The purpose has been to demonstrate the model adequacy to predict forces in the microfield.…”

“…-if critical tool geometrical features, as the edge radius, assume the same magnitude order of the chip thickness, the tool effective rake angle gets highly negative, ploughing forces become more relevant than shearing forces and the cutting specific energy gets higher [3][4];…”

“…-chip removal becomes discontinuous since a minimum uncut chip thickness exists under which no material can be removed from the workpiece ("minimum chip thickness effect") [3][4][5][6];…”