Experimental investigation on 3D chip morphology properties of rotary surface during orthogonal turn-milling of aluminum alloy

Abstract

Orthogonal turn-milling is a novel machining process with the advantages of better surface quality, improved process stability, and higher machining efficiency compared to conventional turning. Chip formation in the turn-milling process plays a significant role in cutting force, tool life, and chatter stability. This paper presents an experimental study on the 3D chip morphology properties during orthogonal turn-milling of Al6061-T6. The effects of cutting parameters on turn-milling chip length and thickness were examined and discussed. The multi-surfaces (including free surface, back surface, and cross-section surface) of turn-milling chip were characterized to understand the mechanism of chip morphology formation. The mixed continuous-and-segmented chips in a single cut and its slipping properties were observed, and the shear band of serrated chip and its ductile fracture property were analyzed. The microhardness variation of turn-milling chip was investigated under different machining parameters. The shear band as well as the profile surface of chip shows increased hardness. This experimental study presents the insight in evaluating the cutting mechanism of turn-milling process and provides guidance for choosing optimum cutting conditions.