TiAlN 코팅공구를 이용한 Ti-6Al-4V 합금의 선삭가공특성에 관한 연구

Abstract

In this paper, turning with the TiA1N coating tool that PVD coating was applied to was processed according to the cutting speed at 30m/min～110m/min, cutting depth of 0.5mm～2.5mm and feed rate at 0.1mm/rev～0.3mm/rev in order to find out the cutting characteristics of Ti-6A1-4V alloy occupying over 50% of titanium alloys. The results on the influence of cutting force by the cutting depth and feed rate, the relationship between the cutting time and the degree of tool wear, tool life according to the cutting characteristics, surface roughness by the feed rate's changes, chip treatment and how machinability affects the hardness are as follows: 1. Cutting depth influences much more on the cutting force than the feed rate and the big difference of the cutting force emerged because the end of tool had the high temperature when the cutting speed was over 70m/min. 2. The cutting force was largely strong when using the tool with the nose with a radius of 1.2mm than that of 0.8mm and tangential force decreased a little, radial force was constant and longitudinal force grew as the cutting speed increased. 3. The crater wear began at the end of cutting edge and the equation with the tool life was set up on the basis of the flank wear. 4. When it comes to the wear characteristics of Ti-6Al-4V alloys, the cutting speed should be under 70m/min to extend the life because the wear speed was very fast at the cutting speed of over 70m/min, while it was largely slow at cutting speed of 50m/min. 5. Surface roughness was largely affected by the feed rate and surface roughness of the precision areas in turning was in the 0.1㎛～0.4㎛ range. Accordingly, feed rate for the precision machining was suitable below 0.15mm/rev. 6. The figure of the chip was largely good as the feed rate increased and chip treatment was the best at the cutting speed of 90m/min and feed rate of 0.25mm/rev～0.3mm/rev according to the chart of the emission chips by the cutting conditions. 7. According to the hardness experiment of processing section for the machinability of titanium alloys, the hardness was hardly different and PVD TiAlN coating tool had no difficulties in work hardening during the cutting processing of titanium.