Wear mechanism analysis in milling of Ti-6Al-4V alloy

Abstract

This article presents an investigation into the wear of cutting tool during milling operation of Ti-6Al-4V using H13A carbide inserts. Wear tests were conducted using machining parameters (feed, speed, and depth of cut) falling in the permissible range recommended by the supplier of the inserts. A wear map was created to identify different regions that characterize the tool wear intensity. The wear map revealed a region of avoidance characterized by higher wear for cutting speed of around 55 m/min and feedrate of 0.15 mm/tooth. The Ti:Al ratio reached values between 4:1 and 6:1 for the cutting parameters that resulted in lower–tool wear rate. However, for higher wear rates, the ratio of Ti:Al did not exhibit any stability across the flank wear land. Scanning electron microscope and energy-dispersive x-ray analysis were performed on the worn inserts to identify the high–tool wear regions and material composition at different locations. Titanium aluminides (TiAl and TiAlN) were found just in the low–tool wear regions, and titanium nitride was found across the avoidance region in the wear map. Microscope and x-ray analysis of inserts in the safety zone clearly revealed a built-up edge on the cutting edge of the tools.