Study On Tool Embedded Thin Film Thermocouples Measuring Cutting Temperature

In the process of mechanical processing,the cutting heat and the cutting temperature have a great influence on the machining of the workpiece.The thin film thermocouple is one of the convenient and quick methods which can measure the cutting temperature.In order to realize the accurate and real-time monitoring of cutting temperature during turning,in the paper,the related technologies of measuring cutting temperature by tool embedded in thin film thermocouple were studied.Based on studying the principle of temperature measurement of thin-film thermocouples and the new thin film preparation technology,the finite element simulation software DEFORM-3D was used to simulate the temperature field of the tool front surface,and the distribution rule of the temperature field of the tool rake face was analyzed.On the basis of thermocouple temperature measurement theory,different structure schemes of thin-film thermocouple and NiCr-Ni Si embedded thermocouple temperature measuring tools are designed for the temperature distribution rule of tool rake face and flank face.In the FJL-560 a magnetron and ion beam composite sputtering deposition system,an experimental study was conducted on the preparation of NiCr-Ni Si thin-film thermocouple.Using glass slides as a substrate,the effects of argon flow rate,sputtering power,and working pressure on the properties of thin film thermocouple(thin film thickness,surface roughness and resistivity)was studied by single factor experiment.On this basis,the process parameters were optimized and the orthogonal experiment scheme was designed.The experiment was continued on the slide substrate,and the appropriate thermocouple film preparation process parameters were obtained.The optimized sputtering process parameters were applied to the experimental studies on the preparation of thin-film thermocouples on the surface of stainless steel substrates and carbide tools respectively.Then the performance of the thin-film thermocouple sample which prepared on the basis of stainless steel was tested.The results showed that the properties of the electric conductivity and the size of the electrode have basically reached the expected requirements.The sensitivity reached 18.4?V/?,and it's still a little far from perfect.Finally,the samples of different sizes of thin film thermocouples were successfully prepared on the surface of the carbide tool.It laid a foundation for further research on cutting temperature measurement in cutting process.