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

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 55m/min and feedrate of 0.15mm/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.