PROCEDURE FOR FABRICATION OF HOT JOINT OF THERMOCOUPLE OUT OF REFRACTORY METAL Russian patent published in 2010 - IPC G01K7/02 

FIELD: metallurgy.

SUBSTANCE: procedure for fabrication of hot joint of thermocouple out of refractory metals consists in assembly of thermo-electrodes on copper cooler by means of bushing and refractory metal and in their successive welding. Also the thermo-electrodes are assembled with a gap wherein adding metal in form of wire is positioned. Melting temperature of wire T_amm is related to melting temperature of the thermo-electrodes T_et by dependence T_et: - (50…80°C)<=T_amm<=T_et + (50…80°C). Additionally, height of thermo-electrodes overhang above surface of the copper cooler is set within ranges 2…4 of diametre of the thermo-electrodes. Height of adding material overhang above ends of thermo-electrodes is set within ranges not more, than 3 overhangs of the thermo-electrodes above surface of the copper cooler. Welding is done with laser or electron beam with short-time pulses in vacuum or inert medium at duration of each pulse 0.5…2.0 sec.

EFFECT: upgraded accuracy of temperature measurement, increased mechanical strength of joint.

2 cl, 3 dwg