RU1838766C - Process of manufacture of high-temperature film thermocouple - Google Patents

Description

thermocouples; the absence of frit in the films of thermoelectrodes improves the thermoelectric characteristic of the thermocouple and simplifies the registration of thermoEMF due to the decrease in the resistance of the films of thermoelectrodes.

Platinum-rhodium-platinum film thermocouple, for the production of platinum-rhodium thermoelectrode using a paste containing platinum and rhodium in a mass ratio of 89-11, ensures the correspondence of thermoelectric properties, film and wire elements of the thermocouple, and thereby achieving the object of the invention. l. The essence of the proposed method is as follows.

Thermoelectrode pastes are prepared on the basis of fine powders of thermoelectrode metals (e.g. platinum, rhodium, iridium, palladium, silver, gold, etc.) and a liquid organic binder (e.g., a solution of rosin powder in turpentine); a frit paste comprising an aluminophosphate binder and additives (silica, aluminum hydroxide, boron, calcium, barium, chromium, magnesium and titanium dioxide).

Frit paste strips are applied to the surface of the insulating substrate of the test piece along the path of the thermoelectrodes. These bands are dried under atmospheric conditions for three hours, then in an oven with heating to 100 ° C at a speed of 1.5 deg / min. After the part is cooled to room temperature, strips of thermoelectrode pastes are applied on the surface of the formed films with their overlapping in the place of the working spa of the thermocouple. The item is placed in an oven and dried. After that, the component is subjected to high temperature annealing to form thermoelectrodes. The part is cooled to room temperature, and wires of material corresponding to the material of the thermoelectrodes are attached to the free ends of the films of thermoelectrodes. In FIG. shows a turbine turbine blade, prepared by a platinum-rhodium-platinum film thermocouple manufactured by the proposed method; figure 2 and 3 - film thermocouples.

The thermocouple contains film thermoelectrodes 1.2 of platinum rhodium paste (1) and platinum paste (2) deposited on the surface of the blade 3, previously protected by an electrical insulating substrate, along paths 1 and 2, and extension wires 4.5 made of PR-10 platinum-alloy alloy (4) and PLT plates (5).

The above elements are made as follows.

On the surface of part 3 along the path of films 1 and 2, a frit paste deposited on an alumophosphate binder from oxides of silicon, aluminum, boron, calcium, barium, chromium is applied to the electrical insulating substrate by a gap of 0.5-1 mm in the zone of the working spa 6 magnesium, aluminum hydroxide and titanium dioxide. After drying for three hours in atmospheric conditions and in an oven with heating to 100 ° C with a heating rate of 1.5 deg / min, strip branches are applied on top of the films

platinum-rhodium 1 and platinum 2, overlapped together with 6 pastes made up on a rosin-turpentine binder from powders of platinum and rhodium, respectively, in a mass ratio of 89: 11 and platinum /

At the free ends of these bands are made

pads 7 for support junctions 3 x 1.5 mm in size. The part with the applied branches and supporting junctions is placed in an oven and heated to 150 ° C at a speed of 1.5

deg / min with exposure at 150 ° C for

30-40 minutes After drying, the part with the films is kept at a temperature of 1100 ° C for 20 minutes, in order to protect the films from erosion by the work flow over

films (except for the places of the supporting junctions of the free ends of the film thermoelectrodes), films of frit paste are applied, which are dried in air at room temperature for 2 hours, followed by

heating to 1050-1100 ° C for 20 minutes After cooling the parts, wires 4 and 5 are connected.

In order to confirm the effectiveness of the method, film thermocouples are made,

shown in FIGS. 2 and 3, where 1 is a platinum-rhodium thermoelectrode made of paste with a mass ratio of platinum and rhodium 90: 10; platinum rhodium thermoelectrode made of paste with a weight ratio of platinum and rhodium 89; eleven; 1; - extension wire from PR-10; 2 - platinum film thermoelectrode; 2- extension wire from PLT.

Test results showed that

Claims (2)

1. A method of manufacturing a high-temperature film thermocouple, comprising applying a frit in the form of a paste and paste layers from a mixture of powders of thermoelectrode metals and a liquid organic binder onto an electrical insulating substrate; overlapping at the place of formation of the working spa, subsequent drying and high-temperature annealing of the layers to form thermoelectrodes and connecting to the latter extension wires of the same composition as thermoelectrodes, characterized in that. in order to increase the accuracy of measurement, 4 ritts are applied as an additional layer along the route of each of the thermoelectrodes before applying the main layers, and then additional layers are dried at a temperature not exceeding 100 ° C, 2. The method according to p. 1, which includes the fact that when performing an extension wire of a platinum-rhodium alloy PR-10 to a thermoelectrode of a platinum-rhodium-platinum thermocouple, as powders, thermo-electrode metals in one of the main layers pastes use platinum and rhodium in a mass ratio of 89: 11, them.; L L 2 g / - H g 9 ( 9 About g i 2  t V f V