The technical field of temperature measurement, more specifically, relates to a densification method of a tungsten-rhenium thermocouple oxidation resistant coating. The tungsten-rhenium thermocouple oxidation resistance coating is attached to the tungsten-rhenium thermocouple substrate surface, including a transition layer and an oxygen barrier layer on the surface of the transition layer, the thermal expansion coefficient of the transition layer material between the tungsten-rhenium thermocouple substrate material and the oxygen barrier layer selection of materials; Tungsten-rhenium thermocouples described for oxidation resistance coating for isostatic pressing and heat treatment, makes the oxidation coating is more compact, less micro cracks, porosity, lower thermal stress was released at the same time, makes the tungsten-rhenium thermocouples oxidation coating thickness decreased by more than 40%, and the coating above 2000 ℃ aerobic environments will markedly enhance its capability of oxygen erosion resistance, Thus the problem of long time contact temperature measurement in ultra-high temperature aerobic environment above 2000℃ can be solved.
For the measurement of ultra-high temperature above 1600℃, non-contact (infrared, optical, etc.) methods are mostly used at present, but the non-contact method not only has slow response speed, but also is far less accurate than direct contact temperature measurement by thermocouple. Platinum-rhodium (Pt-Rh) thermocouple, nickel-Chromium-nickel-silicon thermocouple, iron-Constantan thermocouple and tungsten-rhenium (W-Re) thermocouple are relatively common high-temperature thermocouples, among which, tungsten-rhenium thermocouple has obvious advantages compared with other thermocouples:
(1) High melting point (>3000℃), high strength, good thermal shock resistance, stable chemical properties;
(2) thermoelectric emf (about 2 ~ 3 times of platinum-rhodium thermocouple), high sensitivity;
(3) Large temperature measurement range, working temperature up to 2800℃;
(4) low price (about one-tenth of platinum-rhodium thermocouple).
