High Speed Infrared Measurement of the Cutting Temperature during Milling of Titanium Ti-6Al-4V

Due to its good corrosion, strength and temperature properties as well as its low density, the light metal titanium has many applications in aircraft construction, especially the alloy Ti-6Al-4V. Titanium is considered to be more difficult to machine than steel; it can only be machined at relatively low cutting speeds. The reasons given for this are the low thermal conductivity, the high chemical reactivity and the high cutting temperatures of this material. The temperatures at the cutting edge are often determined in a continuous cut during turning, while they are more difficult to determine in an interrupted cut during milling. This article presents the measurement and calibration of the cutting edge and chip temperature during milling of Ti-6Al-4V using a high-speed infrared camera with an integration time of 1µs for full frame. The tool-chip contact zone is observed with a field of view of 8 x 5 mm. The measured cutting temperatures with typical roughing parameters are much lower during milling at the cutting edge with about 450°C than those in continuous cutting or the more than 1000°C often mentioned in older literature.