An innovative investigation on chip formation mechanisms in micro-milling using natural diamond and tungsten carbide tools

Abstract

This paper presents an analytical approach to investigating the chip formation process in micro-milling aluminum 6082-T6 particularly by using natural diamond and tungsten carbide tools. Through well-designed micro-milling experiments, a comparative study is conducted by utilizing a natural diamond tool with the perfectly sharpened cutting edge and a tungsten carbide tool with the rounded cutting edge respectively. Cutting forces are recorded and analyzed as one of main process indicators. The chip morphology and micro milling processes are analyzed in correlation with cutting force variations in the processes. The size effect, minimum chip thickness and their integral effect are quantitatively assessed against the chip formation process. Research results show that the chips formed during the consecutive revolutions are affected jointly by the cutting tool/workpiece material pair and the cutting edge radius in using tungsten carbide tools; whereas the chips formed by using diamond tools are intact and separate. Furthermore, the cutting force and thrust force are of the same order due to the cutting edge radius cannot be ignored. For using a natural diamond tool with the sharp cutting edge, the resultant cutting force is usually two times higher than the thrust force.