Effect of Microstructure on Cutting Force and Chip Formation during Machining of Ti-6Al-4V Alloy

Abstract

Dry machining was conducted on Ti-6Al-4V alloy with three different types of microstructure: globular, bi-modal and fully lamellar microstructures. The effects of cutting speed on the cutting force and chip formation were investigated. The differences in cutting force and chip morphology are found only at cutting speed lower than 100m/min. The main cutting force and chip thickness when machining Ti-6Al-4V alloy with globular microstructure are lower than these when cutting Ti-6Al-4V alloy with bi-modal and fully lamellar microstructures at cutting speed lower than 100m/min. The tendency of segmented chip formation is the highest for cutting Ti-6Al-4V alloy with fully lamellar microstructure and the lowest for machining Ti-6Al-4V alloy with bi-modal microstructure at cutting speed lower than 100m/min because of their differences in increase of shear strength with strain rate.