Built-in thin film thermocouples in surface textures of cemented carbide tools for cutting temperature measurement

Cemented carbide tools embedded with thin film thermocouples are presented in this paper, to monitor the tool temperature distribution in machining of titanium alloys. In order to protect the thin film sensors from the flowing chips, the fabrication processes which include preparation of micro-grooves on the rake face of commercial tungsten carbide cutting inserts and installation of the thin film sensors in the grooves are proposed. Six K-type thin film thermocouples are implanted in the grooves at a depth of about 100 μm with a 100 μm × 50 μm hot junction area. The tests show that the sensors are reliably insulated with the alloy substrate and have good linearity and uniformity in the measurement. The performance of the fabricated inserts are evaluated in a titanium alloy (Ti6Al4V) turning process with the cutting temperature close to the tool-chip interface obtained online for both continuous and interrupted cutting experiments. The fabricated sensors show good sensitivity and improved durability during the cutting processes.