Wear Mechanisms of PVD and CVD Coated Carbide Tools in Machining Ti6Al4V

Ti6Al4V is widely used, but the tools used for its processing are prone to wear. Tool wear reduces product quality while increasing production costs. Understanding tool wear mechanisms is critical for improving tool performance and avoiding premature wear or damage. The aim of this research is to analyze the wear behavior of PVD SP4019-coated and CVD NL300-coated carbide tools during dry cutting of Ti6Al4V at cutting speeds of 50 to 100m/min. During the cutting process, tangential and radial forces exerted on SP4019 and NL300 coated tools will gradually increase as wear progresses. For cutting speeds between 50 to 80m/min, the flank face wear of the SP4019-coated tool reached 0.05–0.15 mm, while the NL300-coated tool reached approximately 0.25 mm after cutting a length of 500m, with a wear increment of 67%. The observed wear mechanisms for SP4019 and NL300-coated tools encompass diffusion, adhesive, and oxidation wear. Analysis of the SP4019-coated tool revealed a decrease in Ti and Al concentrations to 4.28 and 2.32%, respectively, indicating minimal chip bonding in that area. The presence of C, Co, and W tool matrix elements suggested severe wear of the tool coating. The presence of V and O elements implied potential oxidative and diffusion wear of the workpiece material. It was determined that adhesive-diffusion wear occurred mutually enhanced each other, whereas oxidation and adhesive-diffusion wear had a restricting effect on one another. The results revealed that SP4019 coated tools are more suitable for processing Ti6Al4V than NL300 coated tools, particularly at a cutting speed of 50m/min.