Thermal conducting wire, thermal conducting wire preparation method and equipment

Abstract

The invention relates to the technical field of temperature measuring material preparation, in particular to a thermal conducting wire and a thermal conducting wire preparation method and equipment. The heat conducting wire adopts a three-dimensional structure design of combining a core alloy layer with a gradient protective film, the core alloy is a tungsten-rhenium matrix doped nano dispersed phase (with high stability and high temperature enhancement), the gradient protective film comprises a 100-200nm SiC binding layer and a 5-10nm functional layer, and the three-dimensional structure comprises a variable pitch spiral main body and a wave-shaped ceramic support. The preparation method is based on the whole-course inert atmosphere and comprises the steps of segmented deoxidation, gradient coating, customized annealing and multi-layer packaging. The equipment integrates feeding, a heating furnace, an inert connection assembly, coating, annealing, packaging and a central control system, and can accurately control the temperature and monitor. According to the invention, the sensitivity, the service life and the batch repeatability of the thermal conducting wire are remarkably improved, the detection efficiency is optimized, and the manufacturing cost is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of temperature measurement material preparation, and in particular to a thermal conducting wire, a thermal conducting wire preparation method and equipment. BACKGROUND

[0002] The thermal conducting wire is a core heat-sensitive element of a thermal conductivity detector (TCD) of a gas chromatograph, and its performance directly determines the sensitivity, repeatability and service life of the detector. In the prior art, the thermal conducting wire is mostly made of pure tungsten wire or traditional tungsten-rhenium alloy wire, which has the following key defects: (1) Material performance bottleneck: the traditional tungsten-rhenium wire has poor oxidation resistance and is easily oxidized and corroded in a carrier gas containing impurities or water vapor, and its service life is usually less than 1000 hours; and it is prone to recrystallization at high temperatures, resulting in large fluctuations in resistivity (batch deviation > 3%), which in turn causes unstable detection sensitivity.

[0003] (2) Defects in preparation process: in the existing process, the "deoxidation-coating film-annealing" process of the thermal conducting wire is dispersed, and the thermal conducting wire is easily oxidized again during the module transfer process due to contact with air; the annealing cooling curve is single and cannot adapt to the phase change requirements of different alloys, and the residual internal stress causes poor batch repeatability (RSD > 5%).

[0004] (3) Limitations in structure design: the traditional thermal conducting wire adopts an equal-pitch spiral or straight-line structure, and vortexes are easily generated when the gas flows through, resulting in uneven heat field distribution, a response time of more than 120 ms, and a measurement error of ± 2.1%, which is difficult to meet the high-precision detection requirements.

[0005] (4) Insufficient equipment and packaging: the existing preparation equipment has no special inert atmosphere connecting component, and the coating uniformity depends on manual control; the packaging is mostly single vacuum bag, and the moisture-proof and oxidation-proof ability is weak, and the resistance change rate is > 2% after 6 months of storage, which affects the product shelf life.

[0006] Therefore, how to improve the thermal conducting wire to improve the measurement accuracy is a technical problem to be solved at present. SUMMARY

[0007] The present application relates to the technical field of temperature measurement material preparation, and in particular to a thermal conducting wire, a thermal conducting wire preparation method and equipment.

[0008] To achieve the above-mentioned purpose, the present application provides the following technical solutions: According to one aspect of the present invention, a thermal conductive wire is provided, comprising a core alloy layer and a gradient protective film covering the surface of the core alloy layer, wherein: the core alloy layer is a composite system of a tungsten-rhenium matrix and a nano-dispersed phase, and by weight percentage, the components of the core alloy layer include: W 94.5 to 98.85%, Re 1 to 5%, and nano-dispersed phase 0.15 to 0.6%; the nano-dispersed phase is... and A mixture or HfC; The gradient protective film consists of a 100-200 nm SiC bonding layer and a 5-10 nm layer, from the inside out. Functional layer; the main body of the thermal conductive wire is a variable pitch spiral structure, with the pitch increasing from 50μm to 80μm along the airflow direction, the spiral diameter from 0.3 to 0.5mm, and the two ends are provided with wavy alumina ceramic supports with an amplitude of ±15μm and a wavelength of 200μm.

[0009] According to one embodiment of the present invention, when the core alloy layer is of high stability type, the composition by weight percentage is W 96.5% to 98.85%, Re 1% to 3%, 0.1% to 0.3% 0.05% to 0.1%, grain aspect ratio > 5:1, recrystallization temperature ≥ 1600℃, room temperature resistivity 7.2 to 7.5 μΩ·cm, temperature coefficient of resistance to .

[0010] According to one embodiment of the present invention, when the core alloy layer is a high-temperature reinforced type, the composition by weight percentage is W 94.5 to 95%, Re 4.5 to 5%, HfC 0.5%, creep resistance at 1200°C ≥1500h, and room temperature resistivity 7.6 to 7.8μΩ·cm.

[0011] On the other hand, the present invention also provides a method for preparing a thermal conductive wire, which specifically includes the following steps: S1, Preparation of prefabricated thermal conductive wire: Select a blank that conforms to the core alloy composition and draw it into a wire with a diameter of 15μm to 50μm and a length of 2cm to 10cm; S2, segmented deoxidation: in In a mixed inert atmosphere, 5% of the material is heated according to a stepped heating curve, which is: 200 to 350℃ for 1 to 2 hours, 400 to 600℃ for 1 to 2 hours, and 700 to 900℃ for 1 to 2 hours. S3, Gradient protective film preparation: Maintaining an inert atmosphere, the SiC bonding layer is prepared sequentially using CVD process, followed by ALD process to prepare the... Functional layer; S4, Customized Annealing: In an inert atmosphere, the cooling curve is selected according to the core alloy type, and the cooling rate is controlled with an accuracy of ±0.5℃ / min; S5, multi-layer sealed packaging: sequentially using metal-coated composite film for heat sealing, ceramic box for inert gas filling, and pressure-resistant carton for sealing.

[0012] According to one embodiment of the present invention, in step S3, the conditions of the CVD process are: the precursor is... The volume ratio was 1:4, the temperature was 1100℃, the pressure was 2kPa, and the deposition rate was 30nm / min. The conditions of the ALD process were: trimethylaluminum and water as precursors, temperature 150℃, and pulse cycles 200 to 400 times.

[0013] According to an embodiment of the present invention, in step S4, the cooling curve includes: The first cooling curve for high-stability alloys: 600℃ to 300℃ at a cooling rate of 5℃ / min, hold for 1 hour, then cool to 100℃ at a cooling rate of 2℃ / min, hold for 2 hours, and then cool to room temperature; or, The second cooling curve for high-temperature reinforced alloys is as follows: cooling from 900℃ to 500℃ at a cooling rate of 8℃ / min, holding for 1.5h, then cooling to 200℃ at a cooling rate of 3℃ / min, holding for 2.5h, and finally cooling to room temperature.

[0014] On the other hand, the present invention also provides a thermal conductive wire preparation device, which prepares thermal conductive wires based on a thermal conductive wire preparation method. The device includes: a feeding device, a heating furnace, a first connecting assembly, a coating device, a second connecting assembly, an annealing device, a discharging device, a packaging device, and a central control system, wherein: The feeding device includes an inert atmosphere hopper; The heating furnace has a multi-zone independent temperature control structure with a temperature control accuracy of ±1℃. Both the first connecting assembly and the second connecting assembly are sealed inert gas transition chambers. The coating device integrates a CVD module, an ALD module, and a laser thickness gauge. The annealing device has a built-in PLC controller, which controls the execution of the cooling curve. The central control system connects all modules and monitors and stores process parameters in real time.

[0015] According to one embodiment of the present invention, the heating furnace has a built-in infrared temperature sensor; The CVD module of the coating apparatus includes a precursor preheating system and a gas flow controller; The ALD module includes a precursor pulse valve with a response time of <10ms; The packaging device integrates a hot press sealing machine, an inert gas filling valve, and a threaded sealing mechanism.

[0016] According to one embodiment of the present invention, the multi-zone independent temperature control structure of the heating furnace includes multiple independent heating zones, each heating zone being equipped with a separate temperature sensor and temperature control module, and the furnace is vented with... In a mixed inert atmosphere The volume ratio is 5% to ensure that the tungsten-rhenium matrix is ​​not over-reduced during the oxide layer removal process.

[0017] According to one embodiment of the present invention, the application of a thermal conductivity wire in a gas chromatograph thermal conductivity detector.

[0018] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Significantly improved performance: The sensitivity of the thermal conductive wire is 40% to 60% higher than that of traditional products, the batch repeatability RSD is <1.5%, and the service life is extended by 3 to 5 times (service life ≥5000h in carrier gas containing 5% water vapor). 2. Enhanced process stability: The entire process is conducted in an inert atmosphere to avoid secondary oxidation; a customized annealing curve reduces internal stress; the oxide layer removal rate is ≥99.5%; and the film thickness deviation is <±5%. 3. Optimized detection efficiency: The variable pitch spiral structure reduces airflow turbulence, shortens the response time to below 65ms, and reduces the measurement error to ±0.7%; 4. Storage and Transportation Guarantee: Multi-layer sealed packaging ensures that the product's resistivity change rate is <0.5% after 12 months of storage at room temperature, and the transportation loss rate is <0.5%. 5. High degree of equipment automation: The integrated design reduces human intervention, and the daily output of a single production line is increased to twice that of traditional equipment, while manufacturing costs are reduced by 15% to 20%.

[0019] 6. Using SiC bonding The gradient design, in synergy with the nano-alloy layer, solves the pain points of traditional coatings that are easy to fall off and provide insufficient protection through the gradient coating's "strong bonding + high barrier". Attached Figure Description

[0020] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings: Figure 1 This is a schematic diagram of the main structure of the thermal conductive wire; Figure 2 This is a flowchart of the thermal conductivity wire preparation method; Figure 3 This is a schematic diagram of the integrated structure of the thermal conductive wire preparation equipment.

[0021] Explanation of reference numerals in the attached figures 301. Feeding device; 302. Heating furnace; 303. First connecting assembly; 304. Second connecting assembly; 305. Coating apparatus; 3051. CVD module; 3052. ALD module; 3053. Online monitoring unit; 306. Annealing apparatus; 307. Discharge apparatus; 308. Packaging apparatus; 309. Central control system; Detailed Implementation To facilitate a clear description of the technical solutions in the embodiments of the present invention, the terms "first" and "second" are used to distinguish identical or similar items with essentially the same function and effect. For example, the first threshold and the second threshold are merely used to distinguish different thresholds and do not limit their order. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and that the terms "first" and "second" are not necessarily different.

[0022] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0023] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one" or similar expressions refer to any combination of these items, including any combination of singular or plural items. For example, "at least one of a, b, or c" can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0024] The thermal conductive wire adopts a composite design of "core alloy layer + gradient protective film + three-dimensional optimized structure".

[0025] The core alloy layer is a composite system of "tungsten-rhenium matrix + nano-dispersed phase". It strengthens grain boundaries and inhibits recrystallization through nano-phase, and is divided into two formulations according to performance requirements: In highly stable formulations, the components, by weight percentage, include W 96.5% to 98.85%, Re 1% to 3%, 0.1% to 0.3% 0.05% to 0.1%; of which and Uniformly dispersed in the form of 50 to 100 nm nanoparticles, with a grain aspect ratio > 5:1, recrystallization temperature ≥ 1600℃ (600℃ higher than pure tungsten wire), room temperature resistivity stable at 7.2 to 7.5 μΩ·cm, and temperature coefficient of resistance (TCR). to To ensure consistent sensitivity.

[0026] The high-temperature enhanced formulation, by weight percentage, comprises 94.5% to 95% W, 4.5% to 5% Re, and 0.5% HfC. HfC is the chemical formula for hafnium carbide, a binary ceramic material composed of hafnium and carbon, possessing a very high melting point (close to 3900℃), extremely high hardness, and good high-temperature stability. The HfC nanophase forms a continuous network structure along grain boundaries, exhibiting a creep resistance life of ≥1500h at 1200℃ (7 times better than traditional tungsten-rhenium wire), and a room temperature resistivity of 7.6 to 7.8 μΩ·cm, making it suitable for high-temperature detection scenarios (such as gas analysis >800℃).

[0027] A gradient protective film covers the surface of the core alloy layer and consists of a bonding layer and a functional layer from the inside out, solving the problems of easy peeling and weak oxidation resistance of traditional single oxide layers.

[0028] The bonding layer is a 100-200 nm thick SiC layer prepared by chemical vapor deposition (CVD), under the following deposition conditions: =1:4 (volume ratio), temperature 1100℃, pressure 2kPa, crystallinity >90%, and interfacial peel strength with tungsten rhenium matrix >50MPa, ensuring that the coating is not easy to fall off.

[0029] The functional layer is prepared using atomic layer deposition (ALD) with a thickness of 5 to 10 nm. The layer, using trimethylaluminum and water as precursors, was subjected to a temperature of 150°C and 200 to 400 pulse cycles, achieving a density of 99.9% and an oxygen permeability of < It effectively isolates water vapor and oxygen.

[0030] The main structure of the thermal conductor wire adopts a variable pitch spiral structure, with the pitch increasing from 50μm at the inlet end to 80μm at the outlet end, the spiral diameter from 0.3 to 0.5mm, and the number of turns from 5 to 8. This design reduces airflow eddies, improves the uniformity of the thermal field by 30%, and shortens the response time to less than 65ms.

[0031] The thermal conductor wire's support structure uses a corrugated alumina ceramic support with an amplitude of ±15μm, a wavelength of 200μm, and a stress concentration factor of ≤1.4 (33% lower than traditional straight support), improving vibration resistance and reducing the wire breakage rate from 8% to below 1%.

[0032] like Figure 2 As shown, the thermal conductive wire preparation method is based on the combination of full-process inert atmosphere control and precise temperature profile, realizing integrated production of "deoxidation-coating-annealing-packaging" in sequence. The specific steps are as follows: S1: Preparation of pre-fabricated thermal conductive wire Select billets that conform to the above core alloy formula (such as...) Composite powder sintered billets are processed into fine rods with a diameter of 1 mm to 3 mm by a rotary forging machine, and then drawn in multiple passes by a wire drawing machine (intermediate annealing temperature 800℃ / 10min) to produce wires with a diameter of 15 μm to 50 μm and a length of 2 cm to 10 cm. The wires are placed in an inert atmosphere silo (filled with 99.999% Ar gas) for later use to avoid oxidation during the pretreatment stage.

[0033] S2: Segmented deoxidation treatment The pre-fabricated heat-conducting wire is fed into the heating furnace and introduced... Mixed inert atmosphere ( The surface oxide layer was removed using a stepped heating curve with a volume percentage of 5% and an oxygen content of <10ppm. , , ): Phase 1: Keep warm at 200 to 350℃ for 1 to 2 hours to soften the surface. ; Second stage: Incubate at 400 to 600℃ for 1 to 2 hours to decompose the middle layer. ; Third stage: Keep warm at 700 to 900℃ for 1 to 2 hours to achieve complete restoration. Pure tungsten matrix; The oxide layer removal rate is ≥99.5%, and there is no excessive reduction of the tungsten-rhenium matrix (Re content loss <0.05%).

[0034] S3: Gradient protective film preparation Maintaining an inert atmosphere, the deoxidized thermal conductive wire is transferred to the coating device via the first connecting component (sealed inert transition chamber) to sequentially prepare two protective films: SiC bonding layer preparation (CVD process): Precursor is (Volume ratio 1:4), temperature 1100℃, pressure 2kPa, deposition rate 30nm / min, film thickness 100 to 200nm; film thickness deviation <±5% as monitored in real time by laser thickness gauge.

[0035] Functional layer preparation (ALD process): using trimethylaluminum and water as precursors, temperature 150℃, pulse cycling 200 to 400 times (0.025nm deposition per cycle), film thickness 5 to 10nm; precursor pulse valve response time <10ms to ensure coating uniformity.

[0036] S4: Customized Annealing Process The coated thermal conductive wire is transferred to the annealing device via the second connecting component (with the same structure as the first connecting component). The following cooling profile is selected based on the core alloy type, and the cooling rate is controlled with an accuracy of ±0.5℃ / min to eliminate internal stress. First cooling curve (suitable for high-stability alloys): 600℃ → 300℃ (cooling rate 5℃ / min, holding for 1h) → 100℃ (cooling rate 2℃ / min, holding for 2h) → room temperature; Second cooling curve (suitable for high-temperature reinforced alloys): 900℃ → 500℃ (cooling rate 8℃ / min, holding for 1.5h) → 200℃ (cooling rate 3℃ / min, holding for 2.5h) → room temperature.

[0037] S5: Multi-layer sealed packaging The system employs an inner, middle, and outer three-layer protective structure to prevent oxidation and moisture absorption during storage and transportation. Inner packaging: PET / Al / PE three-layer metal-coated composite film, heat-sealed (temperature 180 to 200℃, pressure 0.3MPa), oxygen permeability < ; Intermediate packaging: Ceramic-lined box (with built-in 4A molecular sieve desiccant, moisture absorption rate <0.5g / 24h), filled with 99.999% pure Ar gas, air replacement rate >99.9%; Outer packaging: Corrugated cardboard box with a thickness of ≥5mm, sealed with silicone sealing ring thread, and with a drop resistance of ≥1.5m without damage.

[0038] like Figure 3 As shown, the thermal conductive wire preparation equipment is an integrated structure used to implement the above preparation method, ensuring controllable process and stable atmosphere throughout the entire process, specifically including: The feeding device 301 includes an inert atmosphere hopper (5 to 10 L capacity, filled with 99.999% Ar gas) and an automatic wire feeding mechanism (wire feeding accuracy ±0.1 mm); a double-layer sealed wire feeding channel is provided between the hopper and the heating furnace (the inner layer is filled with Ar gas at a flow rate of 0.2 to 0.5 L / min; the outer layer is a vacuum isolation layer with a vacuum degree ≤ This prevents the pre-fabricated thermal conductor from coming into contact with air.

[0039] Heating furnace 302 adopts a multi-zone independent temperature control structure (3 independent heating zones). Each heating zone is equipped with a K-type thermocouple (temperature measurement range 0 to 1200℃, accuracy ±0.5℃) and a PID temperature control module, with a temperature control accuracy of ±1℃ and an internal temperature uniformity error of <±2℃. It also features a built-in infrared temperature sensor (detection accuracy ±0.5℃) that provides real-time temperature data feedback to the central control system. The inner wall of the furnace is coated with a 50 to 100 μm thick layer. Ceramic coating prevents the furnace wall from oxidizing and peeling off at high temperatures, thus preventing contamination of the heat-conducting wires.

[0040] Both the first connecting assembly 303 and the second connecting assembly 304 are sealed inert gas transition chambers (volume 1 to 2L), with pneumatic sealing doors at both ends (sealing pressure 0.5MPa). Internally, they are equipped with pressure sensors (range 0 to 0.5MPa, accuracy ±0.01MPa) and a gas replacement system. Each time the chamber doors are opened, a vacuum is first evacuated to... Then, 99.999% Ar gas is added and the process is repeated 3 times to ensure that the oxygen content in the chamber is ≤10ppm. The first connecting component 303 enables seamless connection of the atmosphere between the heating furnace and the coating device, and the second connecting component 304 enables seamless connection between the coating device and the annealing device.

[0041] The coating device 305 integrates a CVD module 3051, an ALD module 3052, and an online monitoring unit 3053. CVD Module 3051: Includes a precursor preheating system (temperature control accuracy ±1℃, preheating temperature 80 to 100℃) and a gas flow controller (accuracy ±0.1 sccm), enabling precise control. and The mixing ratio; ALD Module 3052: Includes precursor pulse valve (response time < 10ms) and vacuum system (vacuum degree ≤ 1× Pa); Online monitoring unit 3053: laser thickness gauge (accuracy ±1nm) and plasma density sensor, which adjust the coating parameters in real time to ensure that the film thickness deviation is <±5%.

[0042] The annealing device 306 includes a heating unit (heating rate of 1 to 10℃ / min), a cooling unit (inert gas cooling, cooling rate of 0.5 to 5℃ / min), and a PLC controller; the PLC can store and execute the above two sets of cooling curves, support the visual editing and parameter locking of temperature-time curves, and avoid human operation deviations.

[0043] Discharge device 307: includes an inert atmosphere transition channel (length 50 to 80 cm, purged with 99.999% Ar gas, airflow rate 0.5 to 1 L / min). Packaging device 308: integrates a hot press sealing machine (temperature range 150 to 250℃, pressure 0.2 to 0.5MPa), an Ar gas filling valve (filling pressure 0.15 to 0.2MPa) and a thread sealing mechanism, automatically completing three-layer packaging, with a daily production capacity of ≥5000 pieces per production line (twice that of traditional equipment).

[0044] The central control system 309 uses an industrial touch screen (10.1 inches) to connect various modules and display parameters such as temperature, atmosphere concentration, coating thickness, and wire feeding rate in real time; it supports the storage and retrieval of more than 100 sets of process formulas and can trace historical data by "equipment number-production date-batch number" (storage time ≥ 3 years); it has an abnormal alarm function (such as oxygen content exceeding the standard, temperature deviation exceeding the limit), and the alarm response time is < 1 second.

[0045] Example 1: High-stability thermal conductivity wire ( Preparation of ).

[0046] Preparation of pre-fabricated thermal conductive wire: Select W-3Re alloy billet (Re content 3.00±0.15%, K content 0.006%), draw it into wire with a diameter of 25μm and a length of 5cm, and place it in the Ar gas hopper of the feeding device.

[0047] Segmented deoxidation: The filament is fed into a heating furnace and purged with oxygen. Mixed atmosphere ( (5%), heated according to the following curve: 200℃ for 1.5h → 400℃ for 1.5h → 800℃ for 1.5h, cooled to 300℃, and then transferred to the coating device through the first connecting component.

[0048] Gradient protective film preparation: CVD preparation of SiC bonding layer: =1 / 4, temperature 1100℃, pressure 2kPa, deposition 30min, film thickness 150nm; ALD preparation Functional layer: Trimethylaluminum / water pulse cycling 300 times, temperature 150℃, film thickness 7nm; The laser thickness gauge monitors the film thickness in real time, and the film thickness deviation is controlled within ±3nm.

[0049] Customized annealing: The sample is transferred to the annealing device via the second connecting component and cooled using the first cooling curve: 600℃ → 300℃ (5℃ / min, holding for 1h) → 100℃ (2℃ / min, holding for 2h) → room temperature. The resistance value after annealing is 110±0.5Ω.

[0050] Multi-layer sealed packaging: sequentially using PET / Al / PE film for heat sealing (190℃, 0.3MPa), ceramic box for Ar gas filling (99.999% purity), and pressure-resistant carton for sealing.

[0051] Performance testing: Under carrier gas (30 mL / min) and 220℃ conditions, the baseline noise is <0.1 mV; after aging at 300℃ for 1000 h, the resistance change rate is 0.6%; after 12 months of storage at room temperature, the resistance change rate is 0.4%.

[0052] Example 2: Preparation of High-Temperature Enhanced Thermal Conductivity Wire (W-5Re-0.5HfC) Preparation of pre-fabricated thermal conductive wire: Select W-5Re alloy billet (Re content 5.0±0.2%), dop with 0.5% HfC nanoparticles (particle size 0.1μm), ball mill for 24h (Ar protection), hot isostatic pressing (2200℃ / 30MPa, 2h), and then draw into wire with a diameter of 30μm and a length of 6cm.

[0053] Segmented deoxidation: The heating furnace atmosphere is... ( (5%), heating curve: 300℃ for 1 hour → 500℃ for 1 hour → 900℃ for 1 hour, then cooled to 400℃ and transferred to the coating device.

[0054] Gradient protective film preparation: SiC layer deposition for 40 min (film thickness 200 nm). Layer cycled 400 times (film thickness 10nm).

[0055] Customized annealing: The second cooling curve is used for cooling: 900℃ → 500℃ (8℃ / min, holding for 1.5h) → 200℃ (3℃ / min, holding for 2.5h) → room temperature.

[0056] Performance testing: Creep resistance at 1200℃ <0.1%; Service life up to 5200h in carrier gas containing 5% water vapor; Temperature coefficient of resistance .

[0057] Example 3: Equipment Operation and Process Traceability Using the equipment of this invention, and simultaneously running the process formula of Example 1, the central control system displays in real time: Temperatures in each zone of the heating furnace: Zone 1 200±1℃, Zone 2 400±1℃, Zone 3 800±1℃; Atmosphere of coating equipment: Content <5ppm, SiC deposition rate 30±1nm / min; The annealing apparatus cooling rate is 5 ± 0.2℃ / min (600→300℃ stage). All parameters are automatically stored in the database, and the manufacturing process of a single thermal conductive wire can be traced via a QR code.

[0058] The thermal conductive wire, preparation method, and equipment of this invention, through multi-dimensional innovation in materials, structure, process, and equipment, have solved the core pain points of existing thermal conductive wires, such as poor oxidation resistance, short lifespan, poor repeatability, slow response, and dispersed equipment and low precision, compared with the existing technology. This has resulted in significant technological progress and industry value.

[0059] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, disclosure, and other materials. In this specification, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple components. A single processor or other unit can implement several functions listed in the specification. While certain measures are described in different embodiments, this does not mean that these measures cannot be combined to produce good results.

[0060] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely illustrative of the invention and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications fall within the scope of the invention and its equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A heat conducting filament, characterized in that, A core alloy layer and a gradient protective film covering the surface of the core alloy layer, wherein: The core alloy layer is a composite system of tungsten-rhenium matrix and nanodispersed phase, the components of the core alloy layer include, by weight percentage, W 94.5 to 98.85%, Re 1 to 5%, nanodispersed phase 0.15 to 0.6%; the nanodispersed phase and a mixture of HfC; The gradient protective film is sequentially 100-200nm SiC bonding layer and 5-10nm The functional layer; the main body of the heat conducting wire is a variable pitch spiral structure, the pitch increases from 50μm to 80μm along the air flow direction, the spiral diameter is 0.3-0.5mm, and the both ends are provided with wavy alumina ceramic supports with amplitude ±15μm and wavelength 200μm.

2. The heat-conducting filament according to claim 1, wherein, When the core alloy layer is high-stability type, the components are W 96.5% to 98.85%, Re 1 to 3%, Mo 0.1 to 0.3%, Cr 0.05 to 0.1%, Ta 0.05 to 0.1%, Nb 0.05 to 0.1%, and C 0.001 to 0.01% by weight percentage, 0.1 to 0.3%, 0.05 to 0.1%, the grain aspect ratio is >5:1, the recrystallization temperature is ≥1600℃, the room temperature resistivity is 7.2 to 7.5 μΩ·cm, and the resistance temperature coefficient to .

3. The heat-conducting filament according to claim 1, wherein, When the core alloy layer is a high-temperature reinforced type, the components are W 94.5-95%, Re 4.5-5%, and HfC 0.5% by weight percentage, the 1200℃ creep rupture life is ≥1500h, and the room temperature resistivity is 7.6-7.8μΩ·cm.

4. A method for preparing a heat conducting filament for preparing a heat conducting filament according to any one of claims 1 to 3, characterized in that, The method comprises the following steps: S1, preparation of a pre-prepared heat-conducting filament: selecting a blank material with core alloy components, and drawing the blank material into a filament with a diameter of 15-50μm and a length of 2-10cm; S2, segmental deoxidation: in under a mixed inert atmosphere, wherein 5%, the wire material is heated in a step-up temperature curve, which is: 200-350℃ for 1-2h, 400-600℃ for 1-2h, 700-900℃ for 1-2h; S3, gradient protective film preparation: maintain inert atmosphere, sequentially prepare SiC bonding layer by CVD process, prepare functional layer; S4, customized annealing: selecting a cooling curve according to the type of the core alloy in an inert atmosphere, and controlling the cooling rate with an accuracy of ±0.5℃ / min; S5, multi-layer sealing and packaging: sequentially using a metal-coated composite film hot-press sealing, a ceramic box inert gas filling, and a pressure-resistant paper box packaging.

5. The heat-conducting filament preparation method according to claim 4, wherein, In step S3, the CVD process has the following conditions: the precursor is , the volume ratio is 1:4, the temperature is 1100℃, the pressure is 2kPa, and the deposition rate is 30nm / min; and the ALD process has the following conditions: trimethylaluminum and water are used as the precursors, the temperature is 150℃, and the pulse cycle is 200 to 400 times.

6. The heat-conducting filament preparation method according to claim 4, wherein, In step S4, the cooling curve comprises: a first cooling curve adapted to a high-stability alloy: cooling from 600℃ to 300℃ at a rate of 5℃ / min, holding for 1h, then cooling to 100℃ at a rate of 2℃ / min, holding for 2h, and then cooling to room temperature; or a second cooling curve adapted to a high-temperature reinforced alloy: cooling from 900℃ to 500℃ at a rate of 8℃ / min, holding for 1.5h, then cooling to 200℃ at a rate of 3℃ / min, holding for 2.5h, and then cooling to room temperature.

7. A hot wire production apparatus for carrying out the hot wire production method according to any one of claims 4 to 6, characterized by The device comprises a feeding device, a heating furnace, a first connecting assembly, a coating device, a second connecting assembly, an annealing device, a discharging device, a packaging device, and a central control system, wherein: The feeding device comprises an inert atmosphere bin; The heating furnace has a multi-zone independent temperature control structure, and the temperature control accuracy is ±1℃; The first connecting assembly and the second connecting assembly are both sealed inert gas transition cabins; The coating device integrates a CVD module, an ALD module, and a laser thickness gauge; The annealing device is internally provided with a PLC controller for controlling the cooling curve according to claim 6; The central control system is connected with each module, and can monitor and store process parameters in real time.

8. The heat-conducting filament preparation device according to claim 7, wherein, The heating furnace is internally provided with an infrared temperature measurement sensor; The CVD module of the coating device comprises a precursor preheating system and a gas flow controller; The ALD module comprises a precursor pulse valve with a response time of <10ms; The packaging device integrates a hot-press sealing machine, an inert gas filling valve, and a screw sealing mechanism.

9. The heat-conducting filament preparation device according to claim 7, wherein, The multi-zone independent temperature control structure of the heating furnace comprises a plurality of independent heating zones, each heating zone is provided with a separate temperature sensor and a temperature control module, and a mixed inert atmosphere The volume ratio of the mixed inert atmosphere is 5%, which ensures that the tungsten-rhenium matrix is not excessively reduced during the oxidation layer removal process.

10. Use of the heat-conducting filament according to any one of claims 1-3 in a thermal conductivity detector of a gas chromatograph.

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