Experimental analysis on tool wear during high-efficiency cutting of titanium alloy

In the machining process of titanium alloy membrane disk, a typical aero-engine component, the machining efficiency is low and the tool wear is serious. Thus, the uncoated cemented carbide tool was used for the cylindrical turning of titanium alloy. The CCD observing system and EDX analysis of SEM were used to study the micro-structural evolution of tool edge, the wear morphology of tool as well as the effect of cutting conditions and serrated chip on tool wear. The results show that the main wear modes during the cylindrical turning of titanium alloy are adhesive wear, diffusive wear and oxidative wear. The cutting speed has the greater influence on tool wear, followed by feed rate and cutting depth. As the cutting speed and feed rate increases, the tool wear becomes more severe. The high-frequency formation of serrated chip leads to the high-frequency change in cutting force. The stress and temperature shocks generate on the tool rake face because of the high-frequency load. These shocks promote the formation of micro-cracks and the tool wear. The usage of coolant can effectively control the tool wear through reducing both adhesion wear of tool flank face and diffusion wear.