A New Fabrication Method of NiCr/NiSi Thin-film Thermocouple Sensor for Workpiece Temperature Measurement in Chemical Explosive Material Machining

With increasing cutting speeds being used in machining operations, the thermal aspects of cutting have become more important. A new fabrication method of nickel-chrome versus nickel-silicon thin-film thermocouple-rf magnetron sputtering is presented. The thin film thermocouples have been directly deposited inside high speed steel cutters and the thickness of the thermocouple junction is only 1.6 mum. The great efforts of this article are devoted to the comparison study between this kind of fabrication method and multiple arc ion plating method introduced in the authors' former work. Static and dynamic calibrations of the NiCr/NiSi thin-film thermocouples are also presented. It is concluded that, comparing to ion plating method, the compositions of the thermocouple thin films deposited by rf magnetron sputtering are closer to those of the alloy targets; the Seebeck coefficient of the thin-film thermocouples are closer to those of standard K-type wire thermocouples; and the thin film thermocouple can respond faster