Research On High-performance Thin Film Thermocouple Temperature Measuring Cutter

In order to solve the technical problem that the temperature in the milling area can’t be tested in real time,a temperature measuring milling cutter integrating milling and temperature measurement functions was prepared.It was annealed and temperature-tested by milling TC4titanium alloy.The specific research contents are as follows:The milling temperature of the titanium alloy is simulated by the ABAQUS finite element software to obtain the temperature field of the milling cutter-workpiece contact area during the milling process.The temperature of the flank tool tip is the highest in the milling tool temperature field and then reaches a stable level after entering stable milling.NiCr-NiSi thin film thermocouple was prepared and annealed in argon atmosphere.The effects of annealing on the seebeck coefficient of NiCr,NiSi functional thin films and thin film thermocouple were studied.Annealing at 200 to 500℃improves the surface uniformity and conductivity of the functional film.The performance of the functional film after annealing at500℃is the best.The seebeck coefficient of the corresponding film thermocouple reaches a maximum of 40.5u V/℃.The thermal cycle test shows that compared with the unannealed film thermocouple,the thermoelectric potential curve of the film thermocouple annealed at 500℃remains stable after continuous thermal shock and high temperature maintenance.A milling temperature acquisition system consisting of a temperature measuring milling cutter and a wireless acquisition system was built.This system can realize the milling temperature data acquisition,wireless transmission and processing functions.A special mechanical mask for temperature measuring milling cutter was designed,then deposited Si O₂insulating film,NiCr,NiSi hot electrode functional film and Si O₂ protective film on the flank edge of YG8 cemented carbide milling cutter in sequence.The temperature measuring cutter was annealed at 500℃in an argon atmosphere and statically calibrated to obtain a temperature measuring cutter seebeck coefficient of 40.5±0.2u V/℃.The three-factor three-level orthogonal milling temperature test test of cutting parameters is designed.The transient milling temperature curve under each parameter is obtained by using the milling temperature acquisition system.The extreme value analysis and variance analysis of the temperature measurement results are carried out to obtain the cutting parameters for TC4.The most significant effect of milling temperature is the milling depth,and the TC4 milling temperature prediction formula is obtained,which provides a feasible solution for the measurement and prediction of milling temperature.