LU502014B1

LU502014B1 - Micro-fine platinum wire for nuclear-grade platinum resistance thermometer, and preparation method

Info

Publication number: LU502014B1
Application number: LU502014A
Authority: LU
Inventors: Jiansheng Wang; Yuchen Xiao; Bao'an Wu; Xiaojun Chen; Yunchun Wang; Huiyi Tang
Original assignee: Chongqing Materials Res Inst Co Ltd
Priority date: 2021-06-17
Filing date: 2021-06-17
Publication date: 2022-12-20

Abstract

The invention relates to a micro-fine platinum wire for a nuclear-grade platinum resistance thermometer and a preparation method thereof. High cleanliness vacuum smelting and bottom-injection casting processes are adopted to effectively ensure the uniformity of components and remove harmful impurities. Precise micromachining and heat treatment are used to precisely control the uniformity of the structure, effectively control the grain size, and eliminate microscopic defects such as internal vacancies, thereby obtaining a micro-fine platinum wire for nuclear-grade platinum resistance thermometers. The micro-fine platinum wire has a minimum wire diameter of 10μm, and a resistance temperature coefficient (α) of 0.003851±0.000003 -1. The micro-fine platinum wire has the advantages of high uniformity, high precision, high stability, long life, radiation resistance, etc, can meet the performance requirements of key materials for nuclear-grade platinum resistance thermometers and can also be promoted and applied in other high-tech fields.

Description

DESCRIPTION ns MICRO-FINE PLATINUM WIRE FOR NUCLEAR GRADE

PLATIUN RESISTANCE THERMOMETER AND PREPARATION

METHOD Field of the Application The invention belongs to the field of metal materials, in particular to a micro-fine platinum wire for a nuclear-grade platinum resistance thermometer and a preparation method.

Background of the Application Nuclear-grade platinum resistance thermometer is an important nuclear-grade temperature sensor. Its key basic material is high-performance micro-fine platinum wire. Its material composition, control of harmful trace elements, regulation of mechanical and electrical properties, wire uniformity and microstructure uniformity is a key factor affecting the measurement accuracy, stability, radiation resistance, and service life of nuclear-grade platinum resistance thermometers.

The current technology uses induction smelting to obtain platinum ingots, and then processes such as forging, rolling, and drawing. The obtained micro-fine platinum wires have problems such as poor composition uniformity, excessive harmful trace elements, poor mechanical properties, difficult to control dimensional accuracy, and poor product consistency. Using the obtained micro-fine platinum wires as a material for nuclear-grade platinum resistance thermometers leads to a shift in the resistance temperature coefficient. of nuclear-grade platinum-resistance thermometers, which greatly reduces the temperature measurement accuracy, stability, service life, and radiation resistance of nuclear-grade platinum resistance thermometers. In addition, it 1s difficult to process micro-fine platinum wires with good surface quality, high dimensional accuracy and high degree of miniaturization with the existing | 1 processing technology. Therefore, the micro-fine platinum wires prepared in the prior LUS02014 art cannot meet the use requirements of nuclear-grade platinum resistance thermometers, so they cannot be applied in engineering.

SUMMARY OF THE INVENTION In view of the deficiencies of the existing micro-fine platinum wire and manufacturing technology, the purpose of the present invention is to provide a micro-fine platinum wire for nuclear grade platinum resistance thermometer and a preparation method, which uses purified high-purity platinum powder as raw material, adds beneficial elements, and uses high-purity smelting, high-uniformity microstructure control and precision micro-processing technology to precisely control material composition and microstructure uniformity, effectively control grain size and eliminate microscopic defects such as internal vacancies, to obtain high-performance micro-fine platinum wire material with high uniformity, high precision, high stability, high stability, long life, radiation resistance, and with a resistance temperature coefficient (a) of 0.003851+0.000003 °C -!, which can meet the key materials requirements of nuclear-grade platinum resistance thermometers.

The purpose of this invention is achieved through the following scheme: The micro-fine platinum wire for a nuclear-grade platinum resistance thermometer comprises the following components by weight: 0.02 to 0.08% of beneficial elements, less than 30 ppm of harmful elements, with the remainder being Pt. The purity of the platinum raw materials is >99.998%.

The beneficial elements are a combination of two or more of Rh, Ir, Pd, and rare earth elements, and the rare earth elements are a combination of two or more of Hf, La, Ce, Gd, and YD.

A preferred technical solution is that the weight percentage of each component is: Rh: 0.005-0.02%, Ir: 0.001-0.02%, rare earth element: 0.001-0.01%, Pt is the remainder, and the content of harmful elements is less than 30ppm.

A preferred technical solution is that the weight percentage of each component is: Rh: 0.008-0.015%, Pd: 0.005-0.008%, rare earth element: 0.001-0.01%, Pt is the | 2 remainder, and the content of harmful elements is less than 30ppm. LUS02014 A preferred technical solution is that the weight percentage of each component is: Pd: 0.005-0.008%, Ir: 0.005-0.01%, rare earth element: 0.003-0.01%, Pt is the remainder, and the content of harmful elements is less than 30ppm.

The main harmful elements that affect the radiation resistance performance are: Co, Cu, B, Si, Cd, etc. The content of harmful elements needs to be strictly controlled and reduced during raw material purity, smelting and processing.

The preparation method of micro-fine platinum wire for nuclear grade platinum resistance thermometer comprises the following steps: 1) taking the components of the micro-fine platinum wire for a nuclear-grade platinum resistance thermometer according to the above proportion, wherein taking 70-80% of the total amount of platinum to wrap the beneficial elements, adopting high-clean vacuum induction smelting with a vacuum degree of 1x107-1x10*Pa and with argon gas protection, keeping the temperature for 5-10 minutes after the materials being completely melted, and performing bottom leakage casting to obtain an intermediate solid solution alloy; and then placing the intermediate solid solution alloy and the remaining platinum in a crucible, adopting high-clean vacuum induction smelting with a vacuum degree of 1x107-1x10*Pa and with argon gas protection, keeping the temperature for 5-10 minutes, and performing bottom leakage casting to obtain a final solid state alloy; 2) hot forging: performing homogenization heat treatment on the final solid state alloy obtained in step 1) at 800-1100°C for 0.5-1 hour, performing hot die forging to obtain a bar, and heat-treating the obtained bar at 500-800°C for 15-30 minutes; 3) wire processing: sequentially performing rough drawing with a deformation amount of <15%, medium drawing with a deformation amount of <10%, and micro-fine drawing with a deformation amount of <6% on the heat-treated bar obtained in step 2) on a wire drawing machine, wherein a total deformation amount is controlled to be < 80%, and performing heat treatment, that is, performing heat treatment at a temperature of 400-700 °C for 10-30 minutes, to draw into a finished | 3 micro-fine platinum wire, which is cleaned to obtain a finished wire. LU502014 Taking 70-80% of the total amount of platinum to wrap the beneficial elements in step 1) adopts a method of layered wrapping: a bottom layer and a top layer are platinum powder, and there is a middle layer between the bottom layer and the top layer, the middle layer is beneficial elements, and the beneficial elements are completely wrapped and compacted with the platinum powder.

The bar in step 2) is a round bar with a size of D4+1 mm.

In the rough drawing stage in step 3), alkaline boiling treatment is first carried out, followed by acid boiling treatment; in the medium drawing stage, alkaline boiling treatment is first carried out, followed by acid boiling treatment; in the micro-fine drawing stage, ultrasonic cleaning with anhydrous ethanol as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, and then ultrasonic cleaning with deionized water as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line. The ceramics, foreign metal impurities (such as iron, copper, silicon, calcium, aluminum, etc.), micro-particles, oil stains and other foreign objects attached to the surface are removed by methods such as alkaline boiling, acid boiling, and online continuous cleaning (the same below).

The alkaline boiling is to use a boiling alkaline solution for cleaning: the volume fraction of deionized water and sodium hydroxide is 1:1.

The acid boiling is to use a boiling acid solution for cleaning: the volume fraction of deionized water and concentrated hydrochloric acid is 1:1.

The effects of adding the above-mentioned content of each beneficial element are as follows:

1. Adding rhodium, palladium and iridium plays the role of solid solution strengthening, adjusting resistance ratio and resistance temperature coefficient.

Rhodium: It adjusts the resistance temperature coefficient, while plays the effect of solid solution strengthening, and its high temperature oxide volatilization characteristics are close to Pt, ensuring the long-term stability of the resistance temperature coefficient; | 4

Iridium: It has a high solid solution strengthening effect in platinum, which can LU502014 significantly increase the hardness and improve the high temperature durability of the alloy; Palladium: It is added together with rhodium and iridium to enhance the solid solution strengthening effect and improve the resistance temperature coefficient.

2. Adding rare earth elements: adding a combination of two or more of the rare earth elements Hf, La, Ce, Gd and Yb in smelting can remove impurities, significantly refine grains, increase recrystallization temperature, enhance toughness and improve processability. They can be oxidized during processing to play a dispersion strengthening role, and they also play a role in regulating the resistance temperature coefficient, that is, they can effectively control the electrical properties, microstructure and mechanical properties of the platinum wire, and improve the overall properties of the alloy.

Through the reasonable combination of the above-mentioned beneficial elements, the resistance temperature coefficient (a) of the material of 0.003851+0.000003 0-1 and the microfabrication are ensured to meet the key materials requirements of nuclear-grade platinum resistance thermometers.

Due to the above technical solution, the platinum material wraps the beneficial elements, reducing the volatilization, burning loss and oxidation of the beneficial elements during the smelting process. By first preparing the intermediate solid solution alloy, and then preparing the final solid state alloy, it is beneficial to the accuracy control of the beneficial elements. Argon gas flow during the smelting process can effectively solve the phenomenon of inhalation of the alloy during the smelting process, which is conducive to refining and homogenization of the structure.

Using hot forging technology, the final solid state alloy obtained in step 1) of the preparation method is homogenized and heat treated at 800-1100 °C for 0.5-1 hour, and then hot forging is performed by circular die forging, to forge into alloy round bars with a size of ®4+1 mm and heat treatment is performed at 500-8005 for 15-30 minutes. After forging, the surface of alloy round bars is rounded and smoothed to | 5 remove defects such as loose structure and holes on the surface of the ingot, to ensure LU502014 the surface quality, which is beneficial to the material microfabrication.

The wire processing of the alloy round bar is performed, and the alloy round bar obtained in step 2) is subjected to rough drawing with a deformation amount of <15%, medium drawing with a deformation amount of <10%, and micro-fine drawing with a deformation amount of <6% on the wire drawing machine. The total deformation amount in each stage is less than or equal to 80%, and heat treatment is carried out in the temperature range of 400-700 [J for 10-30 minutes, and the finished micro-fine platinum wire is drawn, and the cleaned wire is rewound to the finished wire reel through a rewinding device to obtain the finished wire.

For this type of material, reasonable heat treatment and deformation processing technology can effectively ensure the generation of fibrous structure during wire processing, and reduce the damage to the surface of the wire caused by excessive work hardening, which affects the surface quality and yield, greatly improve the processing performance, and improve the quality of the wire. The tension device is used to ensure little or no slippage during wire deformation, thereby improving wire consistency and high surface quality.

Too high heat treatment temperature or too long heating time will cause the material to have coarse grains and inconsistent recrystallization during the heating process, resulting in the generation of "internal vacancies" and dislocations. "Internal vacancies" and dislocations are one of the key factors that reduce the stability and accuracy of temperature measurement. If the temperature is too low or the heating time is too short, the effect of stress relief will not be achieved, which will cause the surface of the wire to be easily damaged and the phenomenon of wire breakage during the drawing process. Similarly, if the deformation amount is too large, it is easy to cause work hardening too fast, and if the deformation amount is too small, the material cannot maintain a good rigidity, which is not conducive to microfabrication. As mentioned above, the microalloyed material formed by the beneficial elements also has the effect of solid solution strengthening, and then through the appropriate | 6 work hardening effect, it is beneficial to improve the micronization yield. LUS02014 The rough drawing stage and the intermediate heat treatment are mainly to remove the ceramics, foreign metal impurities, micro-particles and oil stains and other foreign matter attached to the surface, and then use boiling alkali and acid solutions to clean them successively. That is, alkaline boiling is performed first (the volume fraction of deionized water and sodium hydroxide is 1:1), followed by acid boiling (the volume fraction of deionized water and concentrated hydrochloric acid is 1:1).

The medium drawing stage is mainly to remove the surface microparticle inclusions and oil stains, and the water-based emulsion lubricant is selected, which can play a good role in lubricating and facilitate the drawing of microfilaments. The micro-fine drawing stage is a key stage to ensure a clean wire surface, excellent surface quality, and the wire consistency. In the micro-fine drawing stage, ultrasonic cleaning with anhydrous ethanol as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, and then ultrasonic cleaning with deionized water as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, to remove ceramics, foreign metal impurities, micro-particles and oil stains and other foreign matters attached to the surface.

The micro-fine platinum wire for nuclear-grade platinum resistance thermometer obtained by the preparation method of the present invention has a series of advantages such as high uniformity, high precision, high stability, long life, radiation resistance, and a wide range of applications. The problem of matching and consistency between the electrical properties and mechanical properties of this type of material is solved, and the use requirements of key materials for nuclear-grade platinum resistance thermometers are satisfied. After performance testing and verification, the micro-fine platinum wire for nuclear-grade platinum resistance thermometer of the present invention has a minimum wire diameter of 10 um, a precision of +0.2 um, and a resistance temperature coefficient (a) that meets the nuclear-grade platinum resistance standard requirement of 0.003851+0.000003°C"!. The platinum resistance temperature sensing element made of the platinum wire has good stability, and the maximum | 7 temperature for long-term use can reach 800°C.

The micro-fine platinum wire can LUS02014 also be applied to advanced sensors in other high-tech fields with extremely high degree of micronization and very high temperature measurement accuracy requirements. | 8

DETAILED DESCRIPTION OF THE EMBODIMENTS 10502018 A micro-fine platinum wire for a nuclear-grade platinum resistance thermometer prepared by the preparation method of the present invention comprises the following components by weight: 0.02 to 0.08% of beneficial elements, less than 30 ppm of harmful elements, with the remainder being Pt. The beneficial elements are a combination of two or more of Rh, Ir, Pd, and rare earth elements, and the rare earth elements are a combination of two or more of Hf, La, Ce, Gd, and Yb. The harmful elements are: Co, Cu, B, Si, Cd.

The technical solutions of the present invention are described in the form of steps in conjunction with the following Examples 1-3.

The platinum raw material is prepared by the following method:

1. Hydrolysis Weigh commercially available platinum sponge with a purity of 99.95%, dissolve it by heating with dilute aqua regia, concentrate, use concentrated hydrochloric acid to exhaust the nitric acid, add solid sodium chloride, and evaporate to dryness. Add water to dissolve to obtain a platinum solution, boil, adjust the pH of the platinum solution to 8-10 with chlor-alkali with a mass concentration of 10% (the same as chlor-alkali concentration below), stand at room temperature for 10-20 hours, filter to obtain filtrate 1, and recycle the precipitate.

Concentrate the filtrate to 300ml-500ml, add 100ml-200ml concentrated hydrochloric acid, evaporate to dryness, add deionized water to dissolve, boil, then adjust the pH of the solution to 8-10 with chlor-alkali, keep the constant temperature for 30-60min, and then stand at room temperature for 3-4h, filter to obtain filtrate 2, and recycle the precipitate.

Add a cerium chloride solution with a mass concentration of 1 to 5% in the filtrate 2, boil, adjust the pH of the solution to 8-10, keep a constant temperature for 30min, and then stand at room temperature for 10-20 hours, filter to obtain filtrate 3, and recycle the precipitate; in this way, 3-5 times of hydrolysis are carried out according to the above steps to obtain the filtrate obtained after the multiple times of | 9 hydrolysis. LU502014 Through the above process steps, harmful impurities are effectively removed, and the purity of platinum powder is significantly improved.

2. Hydrazine hydrate reduction The above-mentioned filtrate obtained after the multiple hydrolysis is heated and boiled, slightly cooled and slowly added with hydrazine hydrate until the supernatant is clear, and boiled until there is no alkali liquid bubbles.

3. Filtration and calcination After filtering, the obtained platinum powder was washed with boiling water for several times until the pH value was neutral, calcined in a muffle furnace, kept at 800° C for 30 min, and cooled to room temperature. The high-purity platinum powder, whose Pt content was 99.998%, was taken out to obtain platinum raw materials.

Material purity: beneficial elements > 99.95% (commercially available) Example 1: The weight percentage of each component is: Rh: 0.008%, Ir: 0.006%, Hf:

0.001%, La: 0.001%, Ce: 0.001%, and the contents of Co, Cu, B, Si, and Cd are all <30ppm, and the remainder consists of Pt (platinum raw material, the same below).

Example 2: The weight percentage of each component is: Rh: 0.02%, Pd: 0.005%, Gd:

0.0008%, Yb: 0.0008%, the content of Co, Cu, B, Si, and Cd are all <30ppm, and the remainder consists of Pt.

Example 3: The weight percentage of each component is: Pd: 0.005%, Ir: 0.008%, La:

0.002%, Ce: 0.001%, Gd: 0.001%, Yb: 0.001%, the content of Co, Cu, B, Si, Cd Contents are all <30ppm, the remainder consists of Pt.

Take the components described in Examples 1 to 3, and prepare the micro-fine platinum wire materials for nuclear-grade platinum resistance thermometers according to the steps of the preparation method of the present invention: | 10

1) According to the proportions described in Examples 1 to 3, take each LU502014 component of the micro-fine platinum wire for nuclear-grade platinum resistance thermometers, wherein take 70 to 80% of the total amount of platinum to wrap the beneficial elements that account for 0.5% of the total weight. In the actual operation process, use layered wrapping: first place platinum powder on a bottom layer, and put beneficial elements in the middle, then add platinum powder on the beneficial elements, completely wrap the beneficial elements with platinum powder and compact. Then place all of them in a vacuum induction smelting furnace for smelting with a vacuum degree of 1x107-1x10*Pa and filled with argon gas for protection, keep the temperature for 5-10min after the material is completely melted, and rapid bottom leakage cast into a water-cooled copper mold to obtain an intermediate solid solution alloy.

Place the intermediate solid solution alloy and the remaining platinum in a smelting crucible using high-purity zirconia with a purity of more than 99.9%, place them in a vacuum induction smelting furnace with a vacuum degree of 1x107-1x10*Pa and filled with argon gas for protection, keep the temperature for 5-10min after the material is completely melted, and perform rapid bottom leakage casting to obtain the final solid state alloy with a resistance temperature coefficient (a) of 0.003851+0.000003 1".

2) Hot forging: the final solid state alloy obtained in step 1) is homogenized and heat treated at 800-1100 ° C for 0.5 to 1 hour, the final solid state alloy is subjected to hot forging by circular die forging to obtain a round bar of ®4+1mm, and the obtained round bar is heat-treated at 500-800 [J for 15-30 minutes.

3) Wire processing: the round bar obtained in step 2) is subjected to rough drawing with a deformation amount of <15%, medium drawing with a deformation amount of <10%, and micro-fine drawing with a deformation amount of <6% on the wire drawing machine. The total deformation of the wire is <80%, and the intermediate heat treatment is carried out in the temperature range of 400-700 °C for 10-30 minutes, and the finished fine platinum wire is drawn. After the rough drawing | 11 stage, alkaline boiling treatment is first carried out using an alkali solution of LUS02014 deionized water and sodium hydroxide with a volume fraction of 1:1, followed by acid boiling treatment using an acid solution of deionized water and concentrated hydrochloric with a volume fraction of 1:1. After the medium drawing stage, alkaline boiling treatment is first carried out using an alkali solution of deionized water and sodium hydroxide with a volume fraction of 1:1, followed by acid boiling treatment using an acid solution of deionized water and concentrated hydrochloric with a volume fraction of 1:1. After the micro-fine drawing stage, ultrasonic cleaning with anhydrous ethanol as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, and then ultrasonic cleaning with deionized water as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, to remove the ceramic, foreign metal impurities, micro-particles and oil stains and other foreign matter attached to the surface. The cleaned wire is rewound to the finished wire reel through the rewinding device to obtain the finished wire.

Finally, the performance of the obtained micro-fine platinum wire for nuclear-grade platinum resistance thermometer was tested and the results were obtained.

The micro-fine platinum wire for nuclear-grade platinum resistance thermometer obtained by the preparation method of the present invention has a minimum wire diameter of 10 um, a precision of £0.2 um, and a resistance temperature coefficient (a) that meets the nuclear-grade platinum resistance standard requirement of

0.003851+0.000003°C!. After making it into a wire-wound platinum resistance temperature-sensing element, the resistance change value Ro of the wire-wound platinum resistance temperature-sensing element was tested at 850°C and 0°C for 250 hours before and after respectively, and the resistance change value was converted into a temperature value. It can be concluded that the temperature change value of the wire-wound platinum resistance temperature sensing element does not exceed 0.02°C, and the maximum operating temperature can reach 900°C.

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Claims

WHAT IS CLAIMED IS:

1. À micro-fine platinum wire for a nuclear-grade platinum resistance thermometer, characterized in that it comprises the following components by weight: 0.02 to 0.08% of beneficial elements, less than 30 ppm of harmful elements, with the remainder being Pt.

2. The material according to claim 1, wherein the beneficial elements are a combination of at least two of Rh, Ir, Pd, and rare earth elements, and the rare earth elements are a combination of at least two of Hf, La, Ce, Gd, and YD.

3. The material according to claim 1, wherein the weight percentage of each component is: Rh: 0.005-0.02%, Ir: 0.001-0.02%, rare earth element: 0.001-0.01%, with the remainder being Pt, wherein the content of harmful elements is less than 30ppm.

4. The material according to claim 1, wherein the weight percentage of each component is: Rh: 0.008-0.015%, Pd: 0.005-0.008%, rare earth element: 0.001-0.01%, with the remainder being Pt, wherein the content of harmful elements is less than 30ppm.

5. The material according to claim 1, wherein the weight percentage of each component is: Pd: 0.005-0.008%, Ir: 0.005-0.01%, rare earth element: 0.003-0.01%, with the remainder being Pt, wherein the content of harmful elements is less than 30ppm.

6. The material according to any one of claims 1-5, wherein the harmful elements are: Co, Cu, B, Si, and Cd. | 13

7. A preparation method of micro-fine platinum wire for a nuclear-grade platinum LU502014 resistance thermometer, characterized in that it comprises the following steps: 1) smelting: adopting vacuum induction smelting with a vacuum degree of 1x107-1x10*Pa and with argon gas protection; taking the components of the micro-fine platinum wire for a nuclear-grade platinum resistance thermometer according to the proportion of claim 1, wherein taking 70-80% of the total amount of platinum to wrap the beneficial elements, keeping the temperature for 5-10 minutes after the materials being completely melted, and performing bottom leakage casting to obtain an intermediate solid solution alloy; and then placing the intermediate solid solution alloy and the remaining platinum in a crucible, keeping the temperature for 5-10 minutes after being completely melted, and performing bottom leakage casting to obtain a final solid state alloy; 2) hot forging: performing homogenization heat treatment on the final solid state alloy obtained in step 1) at 800-1100°C for 0.5-1 hour, performing hot die forging to obtain a bar, and heat-treating the obtained bar at 500-800°C for 15-30 minutes; 3) wire processing: sequentially performing rough drawing with a deformation amount of <15%, medium drawing with a deformation amount of <10%, and micro-fine drawing with a deformation amount of <6% on the heat-treated bar obtained in step 2) on a wire drawing machine, wherein a total deformation amount is controlled to be < 80%, and performing heat treatment, that is, performing heat treatment at a temperature of 400-700 °C for 10-30 minutes, to draw into a finished micro-fine platinum wire, which is cleaned to obtain a finished wire.

8. The method according to claim 7, wherein taking 70-80% of the total amount of platinum to wrap the beneficial elements in step 1) adopts a method of layered wrapping: a bottom layer and a top layer are platinum powder, and there is a middle | 14 layer between the bottom layer and the top layer, the middle layer is beneficial LUS02014 elements, and the beneficial elements are completely wrapped and compacted with the platinum powder.

9. The method according to claim 7, wherein the bar in step 2) is a round bar with a size of D4+1mm.

10. The method according to claim 7, wherein in the rough drawing stage in step 3), alkaline boiling treatment is first carried out, followed by acid boiling treatment; in the medium drawing stage, alkaline boiling treatment is first carried out, followed by acid boiling treatment; in the micro-fine drawing stage, ultrasonic cleaning with anhydrous ethanol as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line, and then ultrasonic cleaning with deionized water as the medium is used to continuously clean the drawn finished micro-fine platinum wire on-line .

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