Tool wear prediction of machining hydrogenated titanium alloy Ti6Al4V with uncoated carbide tools

摘要

Tool wear is a problem in the turning of titanium alloy, and it is thus of great importance to understand and quantitatively predict tool wear and tool life. In this paper, a combined tool wear model including abrasive, adhesion, and diffusion wear has been implemented in a commercial finite element (FE) code to predict tool wear. Many key problems in tool wear simulation are presented and discussed such as temperature distribution, the updating of tool geometry, and the smoothing of wear boundary. Subsequently, a finite element method wear prediction model is built, and the results are compared with the experimental value; a good agreement was found. Simulated results showed that cutting force will decrease first and then increase with the increase of the concentration of hydrogen, while tool life varies in the opposite way; therefore, the optimum value of hydrogen content is about 0.3%. The addition of 0.3% hydrogen could improve tool life greatly, and its tool life is more than three times that of the as-received material. The hydrogenation process's favorable effect is limited by cutting parameters and cooling conditions. According to the numerical results, an appropriate machining speed and higher feed is the selection criterion for high-efficiency machining of hydrogenated titanium alloy. Furthermore, a reasonable range of cutting parameters is found; the cutting speed is in the range of 50-100 m/min, and the feed is in 0.15-0.25 mm/rev.