阅读说明：本技术 一种高性能钨铼热电偶丝的制备方法 (Preparation method of high-performance tungsten-rhenium thermocouple wire ) 是由 王焱辉 刘奇 薄新维 韩校宇 王小宇 姚志远 何浩然 刘成超 于 2021-06-17 设计创作，主要内容包括：本发明涉及金属材料制备领域,具体涉及一种高性能钨铼热电偶丝的制备方法,包括以下步骤：1)配料；2)液相混料；3)喷雾制粉；4)焙烧还原；5)压制钨铼坯条；6)烧结；7)电子束熔炼；8)热轧；9)旋锻；10)丝材拉拔；11)电解抛光；12)退火处理,通过采用硝酸镧添加镧元素进行稀土改性,并采用喷雾制粉、电子束熔炼和连续电解抛光等冶金技术,制备出的钨铼热电偶丝丝径为0.08～0.50mm,退火态抗拉强度≥1700MPa,延伸率≥3%,电势稳定性和均匀性高,单级钨铼热电偶丝连续热电势分散性≤25μV,测温允差为±0.125%t(400～2315℃)。(The invention relates to the field of metal material preparation, in particular to a preparation method of a high-performance tungsten-rhenium thermocouple wire, which comprises the following steps: 1) preparing materials; 2) mixing the materials in a liquid phase; 3) spraying to prepare powder; 4) roasting and reducing; 5) pressing a tungsten-rhenium blank bar; 6) sintering; 7) electron beam melting; 8) hot rolling; 9) rotary swaging; 10) drawing the wire; 11) electrolytic polishing; 12) and annealing treatment, namely performing rare earth modification by adding lanthanum element into lanthanum nitrate, and adopting metallurgical technologies such as spray pulverization, electron beam melting, continuous electrolytic polishing and the like to prepare the tungsten-rhenium thermocouple wire with the wire diameter of 0.08-0.50 mm, the annealed tensile strength of more than or equal to 1700MPa, the elongation of more than or equal to 3 percent, high potential stability and uniformity, continuous thermal potential dispersibility of less than or equal to 25 mu V of the single-stage tungsten-rhenium thermocouple wire, and temperature measurement tolerance of +/-0.125% t (400-2315 ℃).)

1. A preparation method of a high-performance tungsten-rhenium thermocouple wire is characterized by comprising the following steps:

1) preparing materials: ammonium rhenate, lanthanum nitrate and ammonium metatungstate are adopted for proportioning, so that the prepared tungsten-rhenium thermocouple wire comprises the following components in percentage by weight:

2.9-26.1% of rhenium, 0.05-0.10% of lanthanum and the balance of tungsten;

2) liquid-phase mixing: dissolving ammonium rhenate and ammonium metatungstate in deionized water, adding lanthanum nitrate to form a mixed solution, and uniformly stirring;

3) spray milling: spraying the mixed solution to prepare powder to obtain tungsten-rhenium alloy powder;

4) roasting and reducing: calcining W-Re alloy powder H₂Under the condition, the roasting temperature is 250-450 ℃, the heat preservation time is 1.5-2.5 h, reduction is carried out after discharging and sieving, the reduction temperature is 900-1200 ℃, the heat preservation time is 2-4 h, and the reduction is carried out and sieving is carried out;

5) pressing a tungsten-rhenium blank bar: pressing the reduced tungsten-rhenium alloy powder into a tungsten-rhenium blank bar;

6) and (3) sintering: the tungsten-rhenium billet is sintered in three stages according to the following conditions: preserving heat at 400-500 ℃ for 30-60 min, preserving heat at 1000-1200 ℃ for 60-90 min, preserving heat at 2000-2200 ℃ for 120-150 min, and cooling along with the furnace;

7) electron beam melting: carrying out electron beam melting on the sintered tungsten-rhenium blank bar to obtain a tungsten-rhenium alloy ingot;

8) hot rolling: carrying out hot rolling on the tungsten-rhenium alloy ingot to prepare a tungsten-rhenium alloy rod, wherein the pass reduction rate is 15-25%, the heating temperature is 1500-1650 ℃, and the heat preservation time is 15-30 min;

9) rotary swaging: performing rotary swaging on the tungsten-rhenium alloy rod after hot rolling, wherein the pass compression rate is 10-15%, the heating temperature is 1400-1600 ℃, and the heat preservation time is 3-7 min, so as to obtain a tungsten-rhenium alloy thin rod;

10) drawing the wire: wire drawing is carried out on the tungsten-rhenium alloy thin rod at the temperature of 700-1300 ℃ to obtain the tungsten-rhenium alloy wire, and the pass compression ratio is 7-12%;

11) electrolytic polishing: adopting continuous electrolytic polishing to clean the tungsten-rhenium alloy wire;

12) annealing treatment: and (4) annealing the tungsten-rhenium alloy wire subjected to electrolytic polishing and cleaning, and cooling along with the furnace.

2. The method of claim 1, wherein: in the step 4) of calcination, H₂The flow rate is 2-5L/min, and the mixture is discharged from the furnace and sieved by a 60-mesh sieve; the reduction temperature is 900-1200 ℃, H₂The flow rate is 4-8L/min, the heat preservation time is 2-4 h, and the reduced product is sieved by a 120-mesh sieve.

3. The method of claim 1, wherein: the diameter of the tungsten-rhenium alloy ingot obtained by electron beam melting in the step 7) is phi 20-30 mm.

4. The method of claim 1, wherein: the diameter of the tungsten-rhenium alloy thin rod obtained by rotary swaging in the step 9) is phi 2.5-3.5 mm.

5. The method of claim 1, wherein: the diameter of the tungsten-rhenium alloy wire obtained by drawing the wire material in the step 10) is phi 0.08-0.5 mm.

6. The method of claim 1, wherein: the continuous electrolytic polishing and cleaning in the step 11) adopts NaOH solution with the electrolytic current of 10-15A and the alkali liquor concentration of 20-30 wt%, and the filament winding speed is 25-45 m/min.

7. The method of claim 1, wherein: the annealing temperature in the step 12) is 1150-1450 ℃, the heat preservation time is 20-45 min, and H₂The flow rate is 4-8L/min.

8. The method of claim 1, wherein: and 3) during spray powder preparation, the atomization rotating speed is 8000-12000 r/min, and the atomization temperature is 120-180 ℃.

9. The method of claim 1, wherein: step 7) when electron beam smelting is carried out, a 250kw electron beam smelting furnace is adopted, and the vacuum range is 10^-3Pa～10^-4Pa, electron beam current of 50-300 mA.

Technical Field

The invention relates to the field of metal material preparation, in particular to a preparation method of a high-performance tungsten-rhenium thermocouple wire.

Background

As a sensor sensitive material with excellent performance for high-temperature measurement, the tungsten-rhenium thermocouple wire has the advantages of high melting point, high strength, wide measurement range, large thermoelectric value and the like, and is widely applied to the temperature measurement fields of ferrous metallurgy, petrochemical industry, aerospace and the like. In most high-temperature transient test processes, the problems of inaccurate measurement, slow response, potential drift and the like of the tungsten-rhenium thermocouple wire often exist due to the severe test environment.

At present, spray pulverization or high-energy ball milling and doping technology is generally adopted to improve the potential uniformity and mechanical property of the tungsten-rhenium thermocouple wire. However, due to the technical limitation of the tungsten-rhenium metallurgical process, although the method can improve the mechanical property of the tungsten-rhenium thermocouple wire, and also improve the thermoelectric stability of the tungsten-rhenium thermocouple wire to a certain extent, because of the component segregation existing in the atomization powder preparation process, the potassium bubbles formed by doping cannot be uniformly controlled, so that the potential uniformity of the tungsten-rhenium thermocouple wire is extremely low, and how to improve the thermoelectric stability and the mechanical property of the tungsten-rhenium thermocouple wire and ensure that the potential uniformity of the prepared tungsten-rhenium thermocouple wire meets the use requirement is an urgent problem to be solved.

Disclosure of Invention

The invention aims to provide a preparation method of a high-performance tungsten-rhenium thermocouple wire aiming at the corresponding defects of the prior art, which adopts the component homogenization and rare earth modification technologies, solves the problem of the component uniformity of tungsten-rhenium by a method of combining rare earth modified spray powder preparation and electron beam melting, ensures that the prepared tungsten-rhenium thermocouple wire has high thermoelectric stability and uniformity and good mechanical performance.

The purpose of the invention is realized by adopting the following scheme: a preparation method of a high-performance tungsten-rhenium thermocouple wire comprises the following steps:

1) preparing materials: ammonium rhenate, lanthanum nitrate and ammonium metatungstate are adopted for proportioning, so that the prepared tungsten-rhenium thermocouple wire comprises the following components in percentage by weight:

rhenium element accounts for 2.9-26.1 wt%, lanthanum element accounts for 0.05-0.10 wt%, and the balance is W;

2) liquid-phase mixing: and dissolving ammonium rhenate and ammonium metatungstate in deionized water, adding lanthanum nitrate to form a mixed solution, uniformly stirring, heating at a constant temperature of 60-100 ℃, and stopping after all materials are completely dissolved.

3) Spray milling: spraying the mixed solution to prepare powder to obtain tungsten-rhenium alloy powder, and controlling the particle size distribution of the tungsten-rhenium pre-alloy powder;

4) roasting and reducing: roasting the tungsten-rhenium alloy powder at the roasting temperature of 250-450 ℃ and H₂The flow rate is 2-5L/min, the heat preservation time is 1.5-2.5 h, and the mixture is discharged and sieved by a 60-mesh sieve; then, reducing at 900-1200 ℃, keeping the temperature for 2-4H at the H2 flow rate of 4-8L/min, and sieving with a 120-mesh sieve after reduction;

5) pressing a tungsten-rhenium blank bar: pressing the reduced tungsten-rhenium alloy powder into a tungsten-rhenium blank bar;

6) and (3) sintering: sintering the tungsten-rhenium blank bar according to the following conditions: keeping the temperature of 400-500 ℃ for 30-60 min, keeping the temperature of 1000-1200 ℃ for 60-90 min, keeping the temperature of 2000-2200 ℃ for 120-150 min, and keeping the temperature at the rate of 7-10 ℃/min, H₂Cooling along with the furnace at the flow rate of 4-8L/min;

7) electron beam melting: carrying out electron beam melting on the sintered tungsten-rhenium billet to obtain a tungsten-rhenium alloy ingot, which is beneficial to alloying and homogenization of tungsten-rhenium elements;

8) hot rolling: carrying out hot rolling on the tungsten-rhenium alloy ingot to prepare a tungsten-rhenium alloy rod, wherein the pass reduction rate is 15-25%, the heating temperature is 1500-1650 ℃, and the heat preservation time is 15-30 min;

9) rotary swaging: performing rotary forging on the tungsten-rhenium alloy rod after hot rolling, wherein the pass compression rate is 10-15%, the heating temperature is 1400-1600 ℃, and the heat preservation time is 3-7 min, so as to obtain a tungsten-rhenium alloy thin rod with the diameter of phi 2.5-phi 3.5 mm;

10) drawing the wire: carrying out wire hot drawing on the tungsten-rhenium alloy thin rod, wherein the heating temperature is 700-1300 ℃, the pass compressibility is 7-12%, and the processing size range of the wire is phi 0.08-0.5 mm, so as to obtain a tungsten-rhenium alloy wire;

11) electrolytic polishing: adopting continuous electrolytic polishing to clean the tungsten-rhenium alloy wire;

12) annealing treatment: annealing the tungsten-rhenium alloy wire subjected to electrolytic polishing and cleaning at 1150-1450 ℃, keeping the temperature for 20-45 min, and carrying out H₂The flow rate is 4-8L/min, and the furnace is cooled.

In the step 4) of calcination, H₂The flow rate is 2-5L/min, and the mixture is discharged from the furnace and sieved by a 60-mesh sieve; the reduction temperature is 900-1200 ℃, H₂The flow rate is 4-8L/min, the heat preservation time is 2-4 h, and the reduced product is sieved by a 120-mesh sieve.

The diameter of the tungsten-rhenium alloy ingot obtained by electron beam melting in the step 7) is phi 20-30 mm.

The diameter of the tungsten-rhenium alloy thin rod obtained by rotary swaging in the step 9) is phi 2.5-3.5 mm.

The diameter of the tungsten-rhenium alloy wire obtained by drawing the wire material in the step 10) is phi 0.5-0.08 mm.

The continuous electrolytic polishing and cleaning in the step 11) adopts NaOH solution with the electrolytic current of 10-15A and the alkali liquor concentration of 20-30 wt%, and the filament winding speed is 25-45 m/min.

The annealing temperature in the step 12) is 1150-1450 ℃, the heat preservation time is 20-45 min, and H₂The flow rate is 4-8L/min,

and 3) during spray powder preparation, the atomization rotating speed is 8000-12000 r/min, and the atomization temperature is 120-180 ℃.

Step 7) when electron beam smelting is carried out, a 250kw electron beam smelting furnace is adopted, and the vacuum range is 10^-3Pa～10^-4Pa, electron beam current of 50-300 mA.

The invention has the following beneficial effects:

(1) the rare earth lanthanum is used for replacing Si, Al and K elements which are used traditionally, and the rare earth lanthanum is dispersed and distributed on crystal boundary, so that the crystal boundary dislocation is better pinned, the migration and disappearance of the crystal boundary are hindered, and the recrystallization temperature and the mechanical property of the tungsten-rhenium alloy wire are improved. Meanwhile, the rare earth element reduces the sensitivity of the annealing temperature to the thermoelectromotive force of the tungsten-rhenium thermocouple wire, is beneficial to the stability control of the potential of the tungsten-rhenium thermocouple wire, reduces the potential drift, improves the temperature measurement precision of the thermocouple wire and solves the problem of inaccurate measurement.

(2) The spray milling and the electron beam melting technology are applied to the preparation of the tungsten-rhenium alloy, the spray milling can effectively control the particle size distribution of the tungsten-rhenium pre-alloy powder, and the electron beam melting is favorable for alloying and homogenization of the tungsten-rhenium element. Compared with the traditional powder metallurgy method, the electron beam melting controls the impurity elements of the tungsten-rhenium alloy, the element purification effect is achieved, the segregation of the tungsten-rhenium element is solved, the potential uniformity of the tungsten-rhenium thermocouple wire is improved, the potential drift is reduced, and the temperature measurement precision is improved.

(3) The continuous electrolytic polishing technology is adopted to polish and clean the surface of the tungsten-rhenium thermocouple wire, so that the surface of the wire is smooth and clean, and the surface quality stability is improved. The continuous electrolytic polishing technology can remove burrs and impurities attached to the surface of the wire material, improve the wire diameter consistency, enable the resistance of the tungsten-rhenium thermocouple wire to be more stable, and solve the problem of slow response of the tungsten-rhenium thermocouple wire.

In conclusion, the method adopts lanthanum nitrate added with lanthanum element to perform rare earth modification, and adopts metallurgical technologies such as spray pulverization, electron beam melting, continuous electrolytic polishing and the like, so that the prepared tungsten-rhenium thermocouple wire has the wire diameter of 0.08-0.50 mm, the annealing tensile strength of more than or equal to 1700MPa, the elongation of more than or equal to 3 percent, high potential stability and uniformity, the continuous thermal potential dispersity of the single-stage tungsten-rhenium thermocouple wire of less than or equal to 25 mu V, the temperature measurement tolerance of +/-0.125% t (400-2315 ℃), namely within the temperature range of 400-2315 ℃, the temperature tolerance error range is 0.125 percent of the specific temperature.

Drawings

FIG. 1 is a flow chart of the present invention;

FIG. 2 is an SEM photograph of the W-Re alloy powder obtained by spray milling in the present invention;

fig. 3 is a result of mechanical property test of the tungsten-rhenium thermocouple wire prepared by the present invention.

Detailed Description

As shown in fig. 1 to 3, a method for preparing a high-performance tungsten-rhenium thermocouple wire includes the following steps:

1) preparing materials: ammonium rhenate, lanthanum nitrate and ammonium metatungstate are adopted for proportioning, so that the prepared tungsten-rhenium thermocouple wire comprises the following components in percentage by weight:

rhenium element accounts for 2.9-26.1 wt%, lanthanum element accounts for 0.05-0.10 wt%, and the balance is W;

the purities of the ammonium rhenate and the ammonium metatungstate are both 99.99%;

2) liquid-phase mixing: dissolving ammonium rhenate and ammonium metatungstate in 1-2L of deionized water, adding lanthanum nitrate to form a mixed solution, uniformly stirring, heating at a constant temperature of 60-100 ℃, and stopping after all materials are completely dissolved.

3) Spray milling: putting the mixed solution into a spray mill, adding 2-5L of deionized water into the spray mill, and controlling the particle size distribution of the tungsten-rhenium pre-alloy powder, wherein the atomization rotation speed is 8000-12000 r/min and the atomization temperature is 120-180 ℃ to obtain tungsten-rhenium alloy powder;

4) roasting and reducing: mixing tungsten-rhenium alloy powderRoasting the powder in a roasting furnace at 250-450 ℃ in a molybdenum boat with H₂The flow rate is 2-5L/min, the heat preservation time is 1.5-2.5 h, and the mixture is discharged and sieved by a 60-mesh sieve; then reducing at 900-1200 ℃ by H₂The flow rate is 4-8L/min, the heat preservation time is 2-4 h, and the reduced product is sieved by a 120-mesh sieve;

5) pressing a tungsten-rhenium blank bar: the method for pressing the reduced tungsten-rhenium alloy powder into the tungsten-rhenium billet comprises the following specific steps:

and (3) filling the reduced tungsten-rhenium alloy powder into a steel pressing die, wherein the pressing pressure is 1-4 MPa, and the pressure maintaining time is 10-15 s, so that a tungsten-rhenium blank strip is formed.

6) And (3) sintering: putting the tungsten-rhenium alloy blank bar formed by pressing into a medium-frequency sintering furnace, and sintering the tungsten-rhenium blank bar according to the following conditions: keeping the temperature of 400-500 ℃ for 30-60 min, keeping the temperature of 1000-1200 ℃ for 60-90 min, keeping the temperature of 2000-2200 ℃ for 120-150 min, and keeping the temperature at the rate of 7-10 ℃/min, H₂Cooling along with the furnace at the flow rate of 4-8L/min;

7) electron beam melting: carrying out electron beam melting on the sintered tungsten-rhenium billet to obtain a tungsten-rhenium alloy ingot, which is beneficial to alloying and homogenization of tungsten-rhenium elements;

adopting a 250kw electron beam smelting furnace, putting the sintered W-Re blank bar into the furnace through an inlet valve, and vacuumizing to 10 DEG^-3Pa～10^-4And Pa, slowly feeding the tungsten-rhenium blank strip into a bombardment area of an electron gun, wherein the electron beam current is 50-300 mA, the molten tungsten-rhenium metal liquid is dripped into a water-cooled copper crucible, and the tungsten-rhenium metal liquid is dripped into the crucible to slowly and spirally pull down a bottom pad to form a tungsten-rhenium alloy ingot with the diameter of phi 20-30 mm.

8) Hot rolling: hot rolling a tungsten-rhenium alloy ingot with the diameter of phi 20-30 mm for 8-10 times by using a hot rolling mill to prepare a tungsten-rhenium alloy rod with the diameter of phi 5-10 mm, wherein the pass compression rate is 15-25%, the heating temperature is 1500-1650 ℃, and the heat preservation time is 15-30 min;

9) rotary swaging: carrying out rotary swaging on the hot-rolled tungsten-rhenium alloy rod for 18-22 times by using a rotary swaging machine to refine grains and improve the uniformity of a grain structure, wherein the pass compression ratio is 10-15%, the heating temperature is 1400-1600 ℃, and the heat preservation time is 3-7 min to obtain a tungsten-rhenium alloy thin rod with the diameter of phi 2.5-phi 3.5 mm;

10) drawing the wire: carrying out wire drawing on the tungsten-rhenium alloy thin rod 16-28 times by using a wire drawing machine, wherein the heating temperature is 700-1300 ℃, the pass compression ratio is 7-12%, and the processing size range of the wire is phi 0.08-0.5 mm, so as to obtain a tungsten-rhenium alloy wire;

11) electrolytic polishing: the continuous electrolytic polishing is adopted to clean the tungsten-rhenium alloy wire, so that the surface of the tungsten-rhenium alloy wire is smooth and clean, and the surface quality is improved.

The continuous electrolytic polishing and cleaning is carried out by adopting 10-15A of electrolytic current and 20-30 wt% of NaOH solution of alkali liquor, and the filament collecting speed is 25-45 m/min.

12) Annealing treatment: stabilizing and annealing the tungsten-rhenium alloy wire subjected to electrolytic polishing and cleaning by adopting an annealing furnace, wherein the annealing temperature is 1150-1450 ℃, the heat preservation time is 20-45 min, and H is₂The flow rate is 4-8L/min, and the furnace is cooled.

The following examples were made according to the above method to prepare high performance tungsten rhenium thermocouple wires of different types:

example 1 this example is illustrated with a WRe3 tungsten rhenium thermocouple wire:

(1) 4002.2g of ammonium metatungstate (NH) were weighed out₄)₆H₂W₁₂O₄₀·4.68H₂O, 138.3g ammonium rhenate and 3gLa (NO)₃)₃6H₂And O, adding the mixture into 1L of deionized water, heating the mixed solution at a constant temperature of 60 ℃, and fully and uniformly stirring.

Filling the prepared mixed solution into a spray powder making machine, adding 2L of deionized water, and carrying out atomization at a rotation speed of 12000r/min and an atomization temperature of 150 ℃ to obtain tungsten-rhenium alloy powder;

then loading the tungsten-rhenium alloy powder into a molybdenum boat to carry out roasting reduction at the roasting temperature of 300 ℃ and H₂The flow rate is 4L/min, the heat preservation time is 2 hours, and the mixture is discharged and sieved by a 60-mesh sieve; then reducing at 900 deg.C₂The flow rate is 4L/min, the heat preservation time is 3h, and the reduced product is sieved by a 120-mesh sieve. Then the obtained product is put into a steel pressing die, the pressing pressure is 1.5MPa, and the dwell time is 10s, so that a tungsten-rhenium alloy billet is formed.

(2) Putting the tungsten-rhenium alloy blank bar into a medium-frequency sintering furnace for sintering, and preserving heat for 30m at 500 DEG Cin, 1200 ℃ heat preservation for 90min, 2200 ℃ heat preservation for 150min, temperature rise speed of 10 ℃/min, H₂The flow rate is 6L/min, and the furnace is cooled.

Then putting the sintered tungsten-rhenium blank bar into an electron beam furnace for smelting with the vacuum degree of 10^-3Pa, the electron beam current is 300mA, after the ingot is pulled into a tungsten-rhenium alloy ingot with the diameter of 20mm, the tungsten-rhenium alloy ingot is hot-rolled for 8-10 times by a hot rolling mill, the pass compression rate is 15%, the heating temperature is 1500 ℃, the heat preservation time is 15min, and the tungsten-rhenium alloy ingot is processed into a tungsten-rhenium alloy rod with the diameter of 5 mm.

And finally, carrying out rotary forging on the tungsten-rhenium alloy rod for 18-22 times, wherein the pass compressibility is 10%, the heating temperature is 1500 ℃, and the heat preservation time is 3min, so that the tungsten-rhenium alloy thin rod with the diameter of phi 2.5mm is obtained.

(3) And (3) drawing the tungsten-rhenium alloy thin rod on a wire drawing machine for 16-28 times, wherein the heating temperature is 900 ℃, the pass compression ratio is 8%, and the processing size of the wire is phi 0.2 mm. Continuous electrolytic polishing is adopted to clean the tungsten-rhenium alloy wire, the electrolytic current is 10A, the concentration of the alkali liquor is 20 percent by weight of NaOH solution, and the wire collecting speed is 25 m/min. Carrying out stabilization annealing treatment on the cleaned tungsten-rhenium alloy wire, wherein the annealing temperature is 1150 ℃, the heat preservation time is 20min, and H₂The flow rate is 4L/min, and the furnace is cooled.

The WRe 3W-Re thermocouple wire obtained by the embodiment is tested by experiments to have the wire diameter of 0.20mm, the annealed tensile strength of 1812MPa, the elongation of 3.5 percent, high potential stability and uniformity, the continuous thermal potential dispersibility of 18 mu V of the single-stage W-Re thermocouple wire, and the temperature measurement tolerance of +/-0.10 percent t (400-2315 ℃).

Example 2 this example is illustrated with a WRe5 tungsten rhenium thermocouple wire:

(1) 3919.5g of ammonium metatungstate (NH) were weighed out₄)₆H₂W₁₂O₄₀·4.68H₂O, 224.7g ammonium rhenate and 3gLa (NO)₃)₃6H₂O, adding into 1.5L deionized water, heating the mixed solution at constant temperature of 80 ℃, and fully and uniformly stirring. And (3) filling the prepared mixed solution into a spray powder making machine, adding 2L of deionized water, and carrying out atomization at the rotation speed of 12000r/min and the atomization temperature of 180 ℃ to obtain tungsten-rhenium alloy mixed powder.

Then the mixed powder is filledRoasting and reducing in a roasting furnace at 350 deg.C in a molybdenum boat₂The flow rate is 4L/min, the heat preservation time is 2 hours, and the mixture is discharged and sieved by a 60-mesh sieve; then reducing at 900 deg.C₂The flow rate is 6L/min, the heat preservation time is 2.5h, the mixture is reduced and sieved by a 120-mesh sieve, and then the mixed powder is filled into a steel pressing die, the pressing pressure is 1.5MPa, and the pressure maintaining time is 12s, so that strip-shaped billet bars are formed.

(2) Sintering the W-Re alloy blank in a medium frequency sintering furnace at 500 deg.C for 30min, 1000 deg.C for 90min, 2000 deg.C for 150min, heating at 10 deg.C/min, and H₂The flow rate is 6L/min, and the furnace is cooled.

Then putting the sintered tungsten-rhenium blank bar into an electron beam furnace for smelting with the vacuum degree of 10^-3Pa, the electron beam current is 280mA, the ingot is pulled to be the tungsten-rhenium alloy ingot with the thickness of phi 25mm, the tungsten-rhenium alloy ingot is hot-rolled for 8-10 times by a hot rolling mill, the pass compression rate is 20%, the heating temperature is 1600 ℃, the heat preservation time is 20min, and the tungsten-rhenium alloy ingot is processed to be a tungsten-rhenium alloy rod with the thickness of phi 7 mm.

And finally, carrying out rotary forging on the tungsten-rhenium alloy rod for 18-22 times, wherein the pass compressibility is 15%, the heating temperature is 1500 ℃, the heat preservation time is 5min, and the tungsten-rhenium alloy thin rod with the diameter of phi 3mm is obtained after rotary forging.

(3) And (3) drawing the tungsten-rhenium alloy thin rod on a wire drawing machine for 16-28 times, wherein the heating temperature is 1000 ℃, the pass compression ratio is 10%, and the processing size of the wire is phi 0.1 mm. Continuous electrolytic polishing is adopted to clean the tungsten-rhenium alloy wire, the electrolytic current is 12A, the concentration of an alkali liquor is 25 percent by weight of NaOH solution, and the wire collecting speed is 30 m/min. Carrying out stabilization annealing treatment on the cleaned tungsten-rhenium alloy wire, wherein the annealing temperature is 1250 ℃, the heat preservation time is 30min, and H₂The flow rate is 6L/min, and the furnace is cooled.

The WRe 5W-Re thermocouple wire obtained by the method of the embodiment is tested to have a wire diameter of 0.10mm, an annealed tensile strength of 1860MPa, an elongation of 6.2%, high potential stability and uniformity, a continuous thermal potential dispersibility of 16 muV of the single-stage W-Re thermocouple wire, and a temperature measurement tolerance of +/-0.12% t (400-2315 ℃).

Example 3 this example is illustrated with a WRe20 tungsten rhenium thermocouple wire:

(1) 3299.3g of tungstenAmmonium salt (NH)₄)₆H₂W₁₂O₄₀·4.68H₂O, 873g ammonium rhenate and 3gLa (NO)₃)₃6H₂O, adding into 1.5L deionized water, heating the mixed solution at constant temperature of 80 ℃, and fully and uniformly stirring. And (3) filling the prepared solution into a spray powder making machine, adding 2L of deionized water, and obtaining tungsten-rhenium alloy mixed powder, wherein the atomization rotation speed is 8000r/min and the atomization temperature is 180 ℃. Loading the mixed powder into a molybdenum boat, roasting and reducing in a roasting furnace at 400 ℃ and H₂The flow rate is 4L/min, the heat preservation time is 2 hours, and the mixture is discharged and sieved by a 60-mesh sieve; then reducing at 1200 deg.C₂The flow rate is 6L/min, the heat preservation time is 4h, and the reduced product is sieved by a 120-mesh sieve. Then the mixture is put into a steel pressing die, the pressing pressure is 3.5MPa, and the pressure maintaining time is 15s, so that strip-shaped billet bars are formed.

(2) Sintering the W-Re alloy blank in a medium frequency sintering furnace at 500 deg.C for 30min, 1000 deg.C for 90min, 2000 deg.C for 120min, heating at 10 deg.C/min, and H₂The flow is 8L/min, after cooling along with the furnace, the sintered tungsten-rhenium blank bar is put into an electron beam furnace for smelting, the vacuum degree is 10^-3Pa, electron beam current 250mA, and ingot guiding to form a tungsten-rhenium alloy ingot with phi of 20 mm.

And then carrying out hot rolling on the tungsten-rhenium alloy ingot for 18-22 times by using a hot rolling mill, wherein the pass compression ratio is 15%, the heating temperature is 1600 ℃, the heat preservation time is 20min, and the tungsten-rhenium alloy ingot is processed into a tungsten-rhenium alloy rod with the diameter of 5 mm.

And finally, carrying out rotary forging on the tungsten-rhenium alloy rod for 18-22 times, wherein the pass compressibility is 10%, the heating temperature is 1600 ℃, the heat preservation time is 3min, and the tungsten-rhenium alloy thin rod with the diameter of phi 2.5mm is obtained after rotary forging.

(3) And (3) drawing the tungsten-rhenium alloy thin rod on a wire drawing machine for 16-28 times, wherein the heating temperature is 1000 ℃, the pass compressibility is 12%, and the processing size of the wire is phi 0.08 mm. Continuous electrolytic polishing is adopted to clean the tungsten-rhenium alloy wire, the electrolytic current is 15A, the concentration of an alkali liquor is 25 percent by weight of NaOH solution, and the wire collecting speed is 30 m/min. Carrying out stabilization annealing treatment on the cleaned tungsten-rhenium alloy wire, wherein the annealing temperature is 1250 ℃, the heat preservation time is 300min, and H₂The flow rate is 6L/min, and the furnace is cooled.

The WRe 20W-Re thermocouple wire obtained by the method of the embodiment is tested by tests to be 0.08mm in wire diameter, 1880MPa in annealed tensile strength, 20.5% in elongation, high in potential stability and uniformity, 17 muV in continuous thermal potential dispersibility of the single-stage W-Re thermocouple wire, and +/-0.12% t (400-2315 ℃) in temperature measurement tolerance.

The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention, and modifications of the present invention by those skilled in the art are within the scope of the present invention without departing from the spirit of the present invention.