A resistance material arc melting and pulse induction heat treatment device and method based on a three-in-one probe and conductivity closed-loop control

Abstract

A resistance material arc melting and pulse induction heat treatment equipment and method based on a three-in-one probe and conductivity closed-loop control, relate to the field of alloy material preparation.The present application solves the problems of excessive conductivity and electromagnetic signal shielding of existing titanium alloy.The three-in-one multifunctional probe is installed on the cavity top cover through the corrugated pipe sealing assembly, and the arc gun module, the material turning spoon module and the thermal image module are arranged in the probe.The thermal image module collects the temperature field time sequence data of the melt and the ingot, and the computer processes to obtain the conductivity estimation value or the conductivity change amount, and the control decision module adjusts the power and frequency of the pulse power supply accordingly.The pulse induction heating device is composed of multiple winding units stacked and wound along the axis of the crucible, and the equivalent winding thickness of the upper coil section is greater than that of the lower coil section, forming an adjustable axial electromagnetic coupling distribution.The present application reduces the number of vacuum interfaces and repeated furnace operation, and realizes the integration of melting, material turning, temperature measurement and conductivity regulation.

Description

Technical Field

[0001] This invention relates to the fields of vacuum arc melting, induction heat treatment, infrared thermal imaging, and intelligent monitoring of material electrical properties, specifically to an equipment and method for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control. Background Technology

[0002] With the popularization of 5G mobile communication technology and the development of thinner, lighter, and more functionally integrated smart terminal devices, increasingly stringent requirements have been placed on the comprehensive performance of mobile phone casing materials. On the one hand, casing materials need to be lightweight, have high specific strength, good corrosion resistance, and excellent thermal conductivity to meet the structural strength and heat dissipation requirements of the device. On the other hand, to ensure antenna radiation efficiency and the normal operation of wireless charging functions, the material must have the lowest possible electromagnetic shielding characteristics, that is, exhibit high "transparency" in electromagnetic compatibility to radio frequency signals. Titanium alloys, with their low density, high specific strength, excellent corrosion resistance, and biocompatibility, have become an important candidate material to replace traditional plastic and stainless steel casings. However, conventional titanium alloys have high electrical conductivity, resulting in strong reflection loss of high-frequency electromagnetic waves, which significantly attenuates the radiation performance of mobile phone antennas and cannot meet the design requirements of low electromagnetic shielding terminal casings.

[0003] Studies have shown that introducing crystal defects such as lattice distortion, dislocations, vacancies, and phase boundaries through specific heat treatment processes can effectively enhance the scattering of conductive electrons, thereby reducing the electrical conductivity of titanium alloys and bringing them closer to the performance target of weak shielding for radio frequency signals. However, in the traditional arc melting method for preparing titanium alloys, the melt solidification rate is too fast, and the cooling conditions and molten pool flow state are difficult to control precisely. This leads to significant differences in the distribution coefficients of alloying elements during the crystallization process, inevitably forming micro-segregation between dendrites and causing problems such as poor microstructure uniformity and uncontrollable phase composition. This inhomogeneity of composition and microstructure not only weakens the mechanical properties of the alloy but also makes the subsequent control of electrical conductivity through heat treatment or processing extremely unstable, making it difficult to achieve precise targeted design for low electrical conductivity. At the same time, conventional induction heating or resistance heating methods have limitations in controlling defect structures, such as low heating efficiency, uneven heating, and the inability to achieve rapid pulsed thermal cycling, making it difficult to effectively control the concentration and distribution of defects in titanium alloys.

[0004] In summary, existing titanium alloy preparation and hot working technologies still have significant shortcomings in achieving low electrical conductivity, controllable microstructure uniformity, and signal-friendly mobile phone casing applications. Summary of the Invention

[0005] The purpose of this invention is to solve the problems of excessively high electrical conductivity and electromagnetic signal shielding in existing titanium alloys. It provides a device and method for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control. To this end, this invention proposes a method combining arc melting and pulse induction heating. Arc melting achieves preliminary alloying of the titanium alloy matrix composition, while pulse induction heating generates rapid thermal cycling and induced eddy current effects, allowing for precise control of the crystal defect structure and phase composition within the alloy. This results in the preparation of a high-temperature titanium alloy mobile phone casing material with uniform microstructure, controllable electrical conductivity, and low electromagnetic shielding properties.

[0006] The technical solution of this invention is:

[0007] This invention provides an arc melting and pulse induction heat treatment device for resistive materials based on a three-in-one probe and conductivity closed-loop control, including a device body and a three-in-one multifunctional probe.

[0008] The three-in-one multi-functional probe includes a probe housing and a switching component, an arc gun module, a material flipping scoop module, and a thermal imaging module disposed therein. The thermal imaging module is vertically fixed in the middle of the probe housing, and the arc gun module and the material flipping scoop module are respectively disposed on both sides of the thermal imaging module. The switching component is used to selectively move the arc gun module or the material flipping scoop module from the retracted position to the working position, while keeping the other unselected module in the retracted position. The thermal imaging module maintains its position during the tool module switching process.

[0009] The switching assembly is disposed within the probe housing and includes a selector, a guide frame, a sliding push rod, a reset component, and a locking component. The guide frame is fixedly disposed within the probe housing, with its lower part located within the probe housing. The sliding push rod is axially slidably disposed within the guide frame, and the arc gun module and the flipping scoop module are respectively mounted on the lower ends of their respective sliding push rods. The selector is slidably disposed on the upper part of the guide frame and is used to drive the corresponding sliding push rod to move from the retracted position to the working position along the guide frame. The reset component acts on each sliding push rod to restore it from the working position to the retracted position. The locking component is disposed between the guide frame and the sliding push rod and is used to lock the sliding push rod extended to the working position and to prevent two or more sliding push rods from extending simultaneously.

[0010] Furthermore, the switching component also includes a range extender gear set respectively disposed on both sides of the arc gun module and the flipping spoon module. Each range extender gear set includes an output rack, a pinion, and a large gear coaxially and fixedly connected. The selector drives the input rack to move, and the input rack meshes with the pinion. The large gear coaxially connected with the pinion meshes with the output rack. The pitch circle radius of the large gear is larger than that of the pinion, so that the moving distance of the sliding push rod is greater than the pressing distance of the selector.

[0011] Furthermore, the three-in-one multi-functional probe is fixed to the top cover of the cavity by a bellows sealing assembly, which is used to maintain a vacuum seal during lifting, rotating or swinging operations; the power supply conductor of the arc gun module passes through the bellows sealing assembly through an insulating electrical feeder, and the thermal imaging module is connected to the image acquisition module through a signal feeder.

[0012] Furthermore, the arc gun module includes a tungsten electrode, an electrode holder, and a ceramic insulating sleeve;

[0013] The material-turning spoon module includes a spoon handle and a spoon head disposed at the lower end of the spoon handle. The spoon head is made of high-temperature resistant metal or high-temperature resistant ceramic. The arc gun module and the material-turning spoon module are respectively connected to a rotary drive motor. The rotary drive motor is used to drive the corresponding tool module to rotate around its axis to adjust the working angle of the tungsten electrode or spoon head relative to the melting groove.

[0014] The thermal imaging module includes an infrared detector head and an infrared transmission protective window located on the front side of the infrared detector head. The field of view of the infrared detector head covers the melt or ingot area inside the water-cooled copper crucible.

[0015] Furthermore, the thermal imaging module also includes a protective shutter. When the arc gun module is in the arc ignition state or the arc intensity exceeds a set threshold, the protective shutter is closed. When entering the temperature measurement or pulse induction heat treatment stage, the protective shutter is opened.

[0016] Furthermore, the equipment body includes a vacuum melting chamber, a water-cooled copper crucible disposed in the vacuum melting chamber, a vacuum system and a water cooling system connected to the vacuum melting chamber, an arc power supply electrically connected to the arc gun module, a pulse induction heating device disposed on the outer periphery of the water-cooled copper crucible, a pulse power supply electrically connected to the pulse induction heating device, and an intelligent control system.

[0017] The intelligent control system includes an image acquisition module, an image preprocessing module, a conductivity prediction module, a control decision module, and a pulse controller, all mounted in a computer. The conductivity prediction module inputs the time-series temperature field data acquired by the thermal imaging module into a pre-trained conductivity prediction model and outputs an estimated conductivity value for the processed material. The control decision module generates a control quantity based on the deviation between the estimated conductivity value and the target value, and adjusts the pulse power supply through the pulse controller. The image preprocessing module performs correction processing on the time-series temperature field data and extracts features such as maximum temperature, average temperature, temperature gradient, heating rate, and cooling rate from the processed time-series temperature field data.

[0018] Furthermore, the conductivity prediction model is obtained by machine learning, and the conductivity reference value is obtained by the four-probe method, eddy current method, or conductivity retest after cooling; the conductivity prediction model is a support vector regression model, random forest model, gradient boosting model, artificial neural network model, convolutional neural network model, long short-term memory network model, or a combination thereof.

[0019] Furthermore, the pulse induction heating device is disposed on the outer periphery of the water-cooled copper crucible and includes multiple stacked winding units that are stacked and wound along the axial direction of the water-cooled copper crucible. The multiple stacked winding units form an upper coil segment and a lower coil segment. The equivalent winding thickness of the upper coil segment is greater than that of the lower coil segment. The equivalent winding thickness is the total radial dimension formed by the radial dimension of the conductor, the number of radial stacking layers, and the insulation gap between adjacent conductors in the corresponding coil segment. The ratio of the equivalent winding thickness of the upper coil segment to that of the lower coil segment is 1.1:1 to 3:1, and the axial turn density of the upper coil segment is not less than that of the lower coil segment. The upper coil segment and the lower coil segment are respectively provided with independent electrical connection terminals. The pulse controller can adjust the current amplitude and pulse frequency of the upper coil segment and the lower coil segment respectively. Each stacked winding unit is wound with a rectangular cross-section hollow copper conductor or an insulated stranded conductor and is separated from the water-cooled copper crucible by an insulating support layer.

[0020] This invention also provides a method for preparing and monitoring resistive materials using an arc melting and pulse induction heat treatment device based on a three-in-one probe and conductivity closed-loop control, comprising the following steps:

[0021] Step 1: Inspect the water-cooled copper crucible, the three-in-one multi-functional probe, the vacuum system, and the water-cooling system. Confirm that all switches and valves are closed, the power adjustment knob is set to zero, and the gas source is in good condition.

[0022] Step 2: After opening the vent valve to restore the furnace pressure to atmospheric pressure, raise the furnace lid, put the alloy material to be melted into the water-cooled copper crucible, and after the loading is completed, lower the furnace lid and lock it.

[0023] Step 3: Turn on the main power and start the vacuum pump. Open the corresponding valves to evacuate the furnace body, reducing the internal pressure to 3×10⁻⁶. -1 Pa to 5×10 -1 Pa;

[0024] Step 4: Evacuate the vacuum melting chamber and fill it with protective gas to a positive pressure state. Then start the vacuum pump again to extract the gas. Repeat the vacuuming and argon filling cycle 2 to 3 times to finally keep the furnace under a protective atmosphere.

[0025] Step 5: Switch the components to put the arc gun module into the working position. The tungsten electrode extends downward to melt the raw material by arc. After melting, the arc gun module retracts. Switch the components to put the tilting spoon module into the working position. The corner drive motor adjusts the angle of the tilting spoon module to flip or stir the ingot. Then the tilting spoon module retracts. Repeat the melting process three to four times.

[0026] Step Six: The image acquisition module acquires the time-series temperature field data of the melt or ingot through the thermal imaging module. The image preprocessing module processes the temperature data, and the conductivity prediction module outputs the conductivity estimate. The control decision module generates a control quantity based on the deviation between the target conductivity value and the conductivity estimate. The pulse controller controls the pulse induction heating device accordingly until the target conductivity range or the preset heat treatment time is reached, thus completing the preparation of the resistive functional material and the monitoring of conductivity changes.

[0027] Step 7: Maintain the atmosphere inside the furnace to allow the sample to cool naturally to room temperature. After the sample has cooled sufficiently, open the vent valve, raise the top cover of the chamber, remove the finished alloy casting, clean the surface of the water-cooled copper crucible and the vacuum melting chamber, and close all valves, vacuum pumps, gas sources and cooling water.

[0028] Furthermore, in step five, the arc-starting distance between the tungsten electrode and the raw material is 1mm to 3mm, and after a stable arc is formed, the working distance is adjusted to 5mm to 20mm.

[0029] In step six, the output power of the pulse induction heating device is adjusted within the range of 5kW to 60kW. Each function switch sequentially executes the following steps: the current function module stops working, the current function module retracts, the locking device is released, the selection device is switched, the target function module extends, and the locking device is relocked. When the locking device has not confirmed that the target function module is in place, the arc power supply and pulse power supply remain prohibited from output.

[0030] Compared with the prior art, the present invention has the following advantages:

[0031] 1. This invention integrates a fixed thermal imaging module, an arc gun module, and a tilting spoon module into a single probe. The thermal imaging module remains fixed, and the switching component only controls the extension and retraction of the arc gun module and the tilting spoon module, reducing the number of moving parts involved in the switching process. This structure reduces the number of openings in the vacuum melting chamber and the number of independent operating mechanisms, which helps simplify the equipment structure, reduce the space occupied by the equipment, and improve the reliability of the vacuum seal. Simultaneously, each module can be switched without opening the furnace lid or disrupting the protective atmosphere, reducing the risk of air entering the furnace during melting and the oxidation and contamination of the material. A range-extending gear set composed of a coaxial pinion and a large gear converts a short pressing stroke into a longer tool extension stroke, allowing the tungsten electrode and the tilting spoon to reach deeper melting areas without significantly increasing the operating space above the probe. Angle-driven motors, respectively installed on the arc gun module and the tilting spoon module, allow independent adjustment of their working angles after the tool extends, improving the adjustability of the tungsten electrode arc ignition position and the tilting spoon's flipping trajectory.

[0032] 2. This invention innovatively uses a thermal imager to record the spatiotemporal evolution of the material surface temperature field during pulse induction heating and subsequent cooling at high frame rates. Combined with an inverse thermal conduction algorithm, a two-dimensional thermal conductivity distribution image is reconstructed in real time from the non-equilibrium thermal response. This technology requires no physical contact, avoiding interference with the material surface state. It can quickly capture local thermal conductivity anomalies caused by defects such as cracks and compositional segregation, avoiding the severe lag and inability to reflect the transient spatial distribution of heat treatment that are common in conventional methods. The obtained dynamic thermal conductivity data is not only the basis for conductivity inversion but can also be directly fed back to the pulse power supply to adjust the heating waveform in real time, truly realizing full-field visualization of thermophysical parameters and online process control.

[0033] 3. This invention utilizes time-varying thermal conductivity data acquired by a thermal imager and corresponding measured standard electrical conductivity values ​​to train machine learning models such as deep neural networks and random forests, establishing an end-to-end mapping from dynamic characteristics of the temperature field and the spatial spectrum of thermal conductivity to electrical conductivity. This model can autonomously learn the coupling effects of microscopic defects, grain boundary scattering, and phase composition on electrothermal transport, overcoming the limitations of traditional empirical formulas. During inference, only the thermal conductivity variation sequence monitored by thermal imaging needs to be input, and the global electrical conductivity can be output instantly, laying a data foundation for the accurate prediction of electromagnetic shielding performance.

[0034] 4. This invention combines the real-time conductivity distribution output by machine learning with transmission line theory or plane wave shielding models to calculate absorption loss, reflection loss, and total shielding effectiveness in real time on a computer. Since conductivity is the dominant factor determining impedance and attenuation, this calculation can accurately reflect the changing trend of shielding characteristics from near-field to far-field. Operators can visually observe the evolution of the material's final shielding effectiveness curve under current process parameters during heat treatment. If the effectiveness deviates from the target, the pulse energy or application time can be adjusted in a timely manner, truly internalizing quality inspection into the manufacturing process. This eliminates the passivity of traditional "post-inspection" and controls the conductivity of titanium alloy within a preset range, which helps to reduce RF reflection loss and eddy current shielding effects while meeting structural strength, corrosion resistance, and heat dissipation requirements, thereby improving the shielding problems of existing mobile phone casings.

[0035] 5. The pulse induction heating in this invention features highly concentrated energy and instantaneous action only in the required area, achieving a thermal efficiency of over 80% and significantly reducing energy consumption. Simultaneously, the pulse induction heating device employs a gradient structure with a thicker upper section and a thinner lower section, along with a multi-layered coil stacking and winding structure, enabling different axial positions to have varying electromagnetic coupling and heat input adjustment capabilities. By zoning and pulse-controlling each coil segment, it helps compensate for differences in heat dissipation capacity at different locations in the water-cooled copper crucible, reducing the axial temperature gradient inside the melt or ingot and improving heating uniformity. Furthermore, the alternating magnetic field can generate electromagnetic stirring in the conductive melt, promoting melt flow and uniform distribution of alloying elements. This solves the problem of online quality assessment for irregularly shaped electromagnetic shielding components in aerospace and communication equipment, expanding the application boundaries of intelligent manufacturing in the field of complex structural functional materials. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the device of the present invention.

[0037] Figure 2 This is an enlarged structural schematic diagram of the three-in-one multifunctional probe of the present invention.

[0038] Figure 3 This is a schematic diagram of the computer-side temperature field data processing and power supply closed-loop control process.

[0039] Figure 4(a) is a tissue image of the sample after two hours of heat treatment, and Figure 4(b) is a tissue image after six hours of heat treatment.

[0040] Figure 5 This is a line graph showing the change in electrical conductivity of the sample (TC4 alloy) over heat treatment time.

[0041] The components include: 1. Vacuum melting chamber; 2. Chamber top cover; 3. Three-in-one multi-functional probe; 5. Bellows sealing assembly; 6. Operating lever; 7. Switching assembly; 8. Arc gun module; 9. Tungsten electrode; 10. Flipping spoon module; 11. Spoon handle; 12. Spoon head; 13. Thermal imaging module; 14. Infrared detector; 15. Infrared transmission protective window; 16. Signal feedthrough; 17. Water-cooled copper crucible; 18. Melting groove; 19. Crucible inlet; 20. Crucible outlet; 21. Thermal insulation layer; 22. Pulse induction heating device; 23. Upper coil section; 24. Lower coil section; 25. Stacked winding unit. 26. Insulating support layer; 27. Pulse power supply; 28. Computer; 29. ​​Image acquisition module; 30. Image preprocessing module; 31. Conductivity prediction module; 32. Control decision module; 33. Pulse controller; 34. Arc power supply; 35. Vacuum system; 36. Vacuum pumping pipeline; 37. Vacuum pump; 38. Protective gas supply assembly; 39. Pressure sensor; 40. Water cooling system; 41. Locking component; 42. Reset component; 43. Sliding push rod; 44. Guide frame; 45. Selector component; 46. Protective shutter; 47. Angle drive motor; 48. Insulating electrical feeder component; 49. Range extender gear set. Detailed Implementation

[0042] Specific implementation method one: Combining Figures 1 to 3This embodiment describes an arc melting and pulse induction heat treatment device for resistive materials based on a three-in-one probe and conductivity closed-loop control. The device includes a main body and a three-in-one multi-functional probe 3. The probe 3 includes a probe housing and a switching component 7, an arc gun module 8, a tilting spoon module 10, and a thermal imaging module 13 disposed therein. The thermal imaging module 13 is vertically fixed in the middle of the probe housing, and the arc gun module 8 and the tilting spoon module 10 are respectively disposed on both sides of the thermal imaging module 13. The switching component 7 is used to selectively move either the arc gun module 8 or the tilting spoon module 10 from a retracted position to a working position, while keeping the other unselected module in the retracted position. The thermal imaging module 13 maintains its position during tool module switching. The switching component 7 is disposed within the probe housing and includes a selection... The device comprises a selector 45, a guide frame 44, a sliding push rod 43, a reset component 42, and a locking component 41. The guide frame 44 is fixedly disposed within the probe housing, with its lower part located within the probe housing. The sliding push rod 43 is axially slidably disposed within the guide frame 44. The arc gun module 8 and the material-turning spoon module 10 are respectively installed at the lower ends of the corresponding sliding push rods 43. The selector 45 is slidably disposed on the upper part of the guide frame 44 to drive the corresponding sliding push rod 43 to move from the retracted position to the working position along the guide frame 44. The reset component 42 acts on each sliding push rod 43 to restore the sliding push rod 43 from the working position to the retracted position. The locking component 41 is disposed between the guide frame 44 and the sliding push rod 43 to lock the sliding push rod 43 extended to the working position and to restrict two or more sliding push rods 43 from extending simultaneously.

[0043] In this embodiment, the thermal imaging module 13 is fixedly installed in the middle of the three-in-one multi-functional probe 3. The optical axis of the infrared detector head 14 always faces the melting groove 18, and the thermal imaging module 13 does not participate in mechanical switching. The guide frame 44 is provided with guide channels on both sides of the thermal imaging module 13, and the arc gun module 8 and the tipping spoon module 10 are respectively installed at the lower end of the corresponding sliding push rod 43.

[0044] Specific Implementation Method Two: Combining Figure 2 In this embodiment, the switching component 7 further includes a range extender gear set 49 respectively disposed on both sides of the arc gun module 8 and the material scoop module 10. Each range extender gear set 49 includes an output rack, a pinion, and a gear coaxially fixedly connected. The selector 45 drives the input rack to move, and the input rack meshes with the pinion. The gear coaxially connected with the pinion meshes with the output rack. The pitch circle radius of the gear is larger than that of the pinion, so that the moving distance of the sliding push rod 43 is greater than the pressing distance of the selector 45.

[0045] In this embodiment, the two range-extending mechanisms operate independently and are prevented from extending simultaneously by a locking element 41 or a mechanical limiting structure. The infrared detector head 14 remains fixed throughout the aforementioned extension and rotation adjustments. Depending on the thermal imager's wavelength, the infrared transmission protective window 15 can be made of sapphire, calcium fluoride, germanium, or zinc selenide.

[0046] In this embodiment, a small pressing stroke of the selector 45 can be converted into a larger output stroke of the sliding push rod 43. When the selector 45 for the arc position is pressed, the input rack moves downward and drives the pinion to rotate. The pinion drives the large gear, which is fixed coaxially with it, to rotate synchronously. The large gear drives the corresponding output rack to move downward, thereby extending the arc gun module 8 and the tungsten electrode 9 into the melting area. After reaching the working position, the locking member 41 engages with the sliding push rod 43 to keep the arc gun module 8 in the extended position.

[0047] Specific implementation method three: Combining Figure 1 In this embodiment, the three-in-one multi-functional probe 3 is fixed to the top cover 2 of the cavity by a bellows sealing assembly 5. The bellows sealing assembly 5 is used to maintain a vacuum seal during lifting, rotating or swinging operations. The power supply conductor of the arc gun module 8 passes through the bellows sealing assembly 5 through an insulating electrical feeder. The thermal imaging module 13 is connected to the image acquisition module 29 through a signal feeder 16.

[0048] While ensuring the high vacuum sealing of the cavity, the probe's overall movement and independent power supply and signal transmission for each internal functional module are realized, providing a fundamental guarantee for the engineering application of the core integrated probe.

[0049] Specific implementation method four: Combination Figure 1 and Figure 2 This embodiment describes an arc gun module 8 that includes a tungsten electrode 9, an electrode holder, and a ceramic insulating sleeve.

[0050] The material-turning spoon module 10 includes a spoon handle 11 and a spoon head 12 disposed at the lower end of the spoon handle 11. The spoon head 12 is made of high-temperature resistant metal or high-temperature resistant ceramic. The arc gun module 8 and the material-turning spoon module 10 are respectively connected to a rotary drive motor 47. The rotary drive motor 47 is used to drive the corresponding tool module to rotate around its axis to adjust the working angle of the tungsten electrode 9 or the spoon head 12 relative to the melting groove 18.

[0051] The thermal imaging module 13 includes an infrared detector 14 and an infrared transmission protective window 15 disposed on the front side of the infrared detector 14. The field of view of the infrared detector 14 covers the melt or ingot area inside the water-cooled copper crucible 17.

[0052] After the arc gun module 8 of this embodiment is locked in place, the operator simultaneously controls the corresponding angle drive motor 47 via the operating lever 6 located at the upper end of the probe. The angle drive motor 47 drives the arc gun module 8 to rotate around its mounting axis, thereby adjusting the angle between the tungsten electrode 9 and the raw material. After melting stops, the angle drive motor 47 first restores the arc gun module 8 to the initial angle that allows for retraction, then the locking member 41 is released, and the reset member 42 drives the sliding push rod 43 and the arc gun module 8 to retract upwards.

[0053] The corner drive motor 47 in this embodiment is equipped with a heat insulation shield, a cooling structure and a temperature sensor. The temperature sensor is connected to the intelligent control system and stops the motor when the temperature exceeds a set threshold.

[0054] In addition, the tilting spoon module 10 adopts the same telescopic method. After pressing the tilting stop selection piece 45, the other side's extension gear set 49 drives the corresponding sliding push rod 43 to move downward, so that the spoon handle 11 and spoon head 12 enter the melting groove 18. After the tilting spoon module 10 is locked in place, the corresponding rotation drive motor 47 drives the tilting spoon module 10 to rotate around the rotating shaft, so that the spoon head 12 forms an arc motion, thereby completing the lifting, pushing or flipping of the ingot. The tilting spoon module 10 swings back and forth within a preset rotation angle of 90° to 180° limited by the mechanical limiting piece.

[0055] Specific Implementation Method Five: Combining Figure 2 In this embodiment, the thermal imaging module 13 further includes a protective shutter 46. When the arc gun module 8 is in the arc ignition state or the arc intensity exceeds a set threshold, the protective shutter 46 is closed. When entering the temperature measurement or pulse induction heat treatment stage, the protective shutter 46 is opened.

[0056] This embodiment shuts down the infrared detector 14 to protect it from irreversible damage when the electric arc ignites or the arc light exceeds the threshold, and turns it on during the temperature measurement / heat treatment stage to ensure normal acquisition of temperature field data. This is a key protective measure for the "thermal imaging module" of this invention to work reliably for a long time in harsh front-end environments.

[0057] Specific Implementation Method Six: Combination Figure 1 This embodiment describes the equipment body, which includes a vacuum melting chamber 1, a water-cooled copper crucible 17 disposed in the vacuum melting chamber 1, a vacuum system 35 and a water cooling system 40 connected to the vacuum melting chamber 1, an arc power supply 34 electrically connected to the arc gun module 8, a pulse induction heating device 22 disposed on the outer periphery of the water-cooled copper crucible 17, a pulse power supply 27 electrically connected to the pulse induction heating device 22, and an intelligent control system.

[0058] The intelligent control system includes an image acquisition module 29, an image preprocessing module 30, a conductivity prediction module 31, a control decision module 32, and a pulse controller 33, all housed in a computer 28. The conductivity prediction module 31 inputs the time-series temperature field data acquired by the thermal imaging module 13 into a pre-trained conductivity prediction model and outputs an estimated conductivity value for the processed material. The control decision module 32 generates a control quantity based on the deviation between the estimated conductivity value and the target value, and adjusts the pulse power supply 27 through the pulse controller 33. The image preprocessing module 30 performs correction processing on the time-series temperature field data and extracts features such as maximum temperature, average temperature, temperature gradient, heating rate, and cooling rate from the processed time-series temperature field data.

[0059] The device body of this embodiment also includes a cavity top cover 2, a pulse induction heating device 22, a pulse power supply 27, an arc power supply 34, a vacuum system 35, and a water cooling system 40. The water-cooled copper crucible 17 is located in the lower middle part of the vacuum melting cavity 1, and its melting groove 18 is located below the three-in-one multi-functional probe 3.

[0060] The vacuum system 35 includes a vacuum pumping line 36, a vacuum pump 37, a protective gas supply assembly 38, and a pressure sensor 39. The vacuum pump 37 is connected to the vacuum melting chamber 1 through the vacuum pumping line 36, the protective gas supply assembly 38 supplies argon or other inert gases into the chamber, and the pressure sensor 39 outputs a pressure signal to the computer 28.

[0061] Computer 28 communicates with the monitoring elements of thermal imaging module 13, pulse controller 33, pressure sensor 39, and water cooling system 40. Computer 28 can display the status of temperature field, conductivity estimation, etc.

[0062] Computer 28 is connected to the three-in-one multi-functional probe 3, pulse power supply 27, and arc power supply 34 respectively, and is used to coordinate the working sequence of different functional modules and adjust the heating process according to the material state. Thermal imaging module 13 continuously acquires temperature distribution images of the surface of melt or ingot and transmits the images to computer 28 through signal feeder 16.

[0063] The image acquisition module 29 in computer 28 receives thermal images at different times, and the image preprocessing module 30 performs noise reduction, temperature correction, and effective region extraction on the images. Based on the heat conduction equation... The thermal conductivity of the material is inverted. Here, ρ is the material density, Cp is the specific heat capacity of the material, T is the temperature, t is the time, k is the thermal conductivity to be determined, and Q is the equivalent heat source generated by pulse induction heating.

[0064] The computer continuously adjusts the thermal conductivity k based on the known material dimensions, pulse input energy, and boundary heat dissipation conditions to minimize the difference between the temperature field calculated by the heat conduction model and the temperature field actually measured by the thermal imaging module 13. This yields the equivalent thermal conductivity, the rate of change of thermal conductivity, and the spatial distribution characteristics of thermal conductivity at each moment.

[0065] During the creation of training labels, training samples that have undergone different heat treatment times are stopped from heating and cooled to a specified temperature. Then, their conductivity reference values ​​are measured using the four-probe method or eddy current method. According to the sample number and heat treatment time, the conductivity reference values ​​are matched with the corresponding temperature field data, thermal conductivity data, and pulse heating parameters to form a set of training samples. The conductivity prediction module 31 uses the machine learning model trained on these samples. The control decision module 32 compares the conductivity estimate output by the conductivity prediction module 31 with a pre-set conductivity target range and determines whether to increase, decrease, or stop heating based on the deviation between the two. The pulse controller 33 adjusts the output power and pulse frequency of the pulse power supply 27 according to the control quantity given by the control decision module 32, enabling the pulse induction heating device 22 to heat or maintain the material in stages. This forms a cyclical control process of "temperature field acquisition—conductivity prediction—control quantity calculation—pulse heating adjustment—temperature field re-acquisition" until the conductivity estimate enters the target range or meets the preset termination condition. This setup allows arc melting, material turning, temperature measurement, and pulse heating to automatically coordinate in a prescribed sequence, preventing collisions caused by different modules simultaneously entering the melting area. It also allows for the indirect acquisition of changes in the electrical conductivity of high-temperature materials using thermal imaging data and machine learning models.

[0066] Specific implementation method seven: Combination Figure 3 This embodiment describes a conductivity prediction model 31 obtained through machine learning. The conductivity reference value is obtained by the four-probe method, eddy current method, or conductivity retesting after cooling. The conductivity prediction model 31 is a support vector regression model, random forest model, gradient boosting model, artificial neural network model, convolutional neural network model, long short-term memory network model, or a combination thereof.

[0067] This implementation method solves the problem of direct conductivity measurement under high temperature conditions by introducing a machine learning model, and covers the mainstream implementation paths by using multiple model types, providing a reliable source of conductivity feedback signal for the entire closed-loop control system.

[0068] Specific implementation method eight: Combination Figure 1In this embodiment, the pulse induction heating device 22 is disposed on the outer periphery of the water-cooled copper crucible 17 and includes multiple stacked winding units 25 stacked and wound along the axial direction of the water-cooled copper crucible 17. The multiple stacked winding units 25 form an upper coil segment 23 and a lower coil segment 24. The equivalent winding thickness of the upper coil segment 23 is greater than the equivalent winding thickness of the lower coil segment 24. The equivalent winding thickness is the total radial dimension formed by the radial dimension of the conductor, the number of radial stacking layers, and the insulation gap between adjacent conductors in the corresponding coil segment. The ratio of the equivalent winding thickness of the upper coil segment 23 to the lower coil segment 24 is 1.1:1 to 3:1, and the axial turn density of the upper coil segment 23 is not less than the axial turn density of the lower coil segment 24; the upper coil segment 23 and the lower coil segment 24 are respectively provided with independent electrical connection terminals, and the pulse controller 33 can adjust the current amplitude and pulse frequency of the upper coil segment 23 and the lower coil segment 24 respectively; each stacked winding unit 25 is wound with a rectangular cross-section hollow copper conductor or insulated stranded conductor, and is separated from the water-cooled copper crucible 17 by an insulating support layer 26.

[0069] In this embodiment, the pulse induction heating device 22 is located between the outer wall of the water-cooled copper crucible 17 and the inner wall of the vacuum melting chamber 1. Multiple stacked winding units 25 can be annular, near-rectangular, or segmented annular structures adapted to the outer contour of the water-cooled copper crucible 17, and are stacked layer by layer along the axis of the water-cooled copper crucible 17. The upper coil segment 23 employs a larger conductor radial dimension, a greater number of radial stacked layers, a smaller axial turn spacing, or a combination thereof; the lower coil segment 24 employs a smaller conductor radial dimension, a fewer radial stacked layers, a larger axial turn spacing, or a combination thereof, thereby making the equivalent winding thickness of the upper coil segment 23 greater than that of the lower coil segment 24. The ratio of the equivalent winding thickness of the upper coil segment 23 to the lower coil segment 24 is 1.1:1 to 3:1. Each stacked winding unit 25 is positioned and maintained at a set spacing by an insulating support layer 26.

[0070] Specific Implementation Method Nine: Combining Figures 1 to 3 This embodiment describes the following steps:

[0071] Step 1: Inspect the water-cooled copper crucible 17, the three-in-one multi-functional probe 3, the vacuum system 35 and the water-cooling system 40, and confirm that the switches and valves of each part are in the closed state, the power adjustment knob is set to zero, and the gas source is in good condition.

[0072] Step 2: After opening the vent valve to restore the furnace pressure to atmospheric pressure, raise the furnace cover and place the alloy material to be melted into the water-cooled copper crucible 17. After loading, lower the furnace cover and lock it.

[0073] Step 3: Turn on the main power and start the vacuum pump. Open the corresponding valves to evacuate the furnace body, reducing the internal pressure to 3×10⁻⁶.-1 Pa to 5×10 -1 Pa;

[0074] Step 4: Evacuate the vacuum melting chamber 1 and fill it with protective gas to a positive pressure state. Then start the vacuum pump again to extract the gas. Repeat the vacuuming and argon filling cycle 2 to 3 times to finally keep the furnace under a protective atmosphere.

[0075] Step 5: Switch component 7 to bring the arc gun module 8 into the working position. The tungsten electrode 9 extends downward to perform arc melting on the raw material. After melting is completed, the arc gun module 8 retracts. Switch component 7 to bring the tilting spoon module 10 into the working position. The corner drive motor 47 adjusts the angle of the tilting spoon module 10 to flip or stir the ingot. Then, the tilting spoon module 10 retracts. Repeat the melting process three to four times.

[0076] Step Six: The image acquisition module 29 acquires the time-series data of the temperature field of the melt or ingot through the thermal imaging module 13. The image preprocessing module 30 processes the temperature data, and the conductivity prediction module 31 outputs the conductivity estimate. The control decision module 32 generates a control quantity based on the deviation between the conductivity target value and the conductivity estimate. The pulse controller 33 controls the pulse induction heating device 22 accordingly until the conductivity target range is reached or the preset heat treatment time is reached, thus completing the preparation of the resistive functional material and the monitoring of conductivity changes.

[0077] Step 7: Maintain the atmosphere inside the furnace to allow the sample to cool naturally to room temperature. After the sample has cooled sufficiently, open the vent valve, raise the top cover 2 of the chamber, remove the finished alloy casting, clean the surface of the water-cooled copper crucible 17 and the vacuum melting chamber 1, and close all valves, vacuum pumps, gas sources and cooling water.

[0078] Specific Implementation Method Ten: Combining Figure 1 and Figure 2 In this embodiment, the arc-starting distance between the tungsten electrode 9 and the raw material in step five is 1 mm to 3 mm. After a stable arc is formed, the working distance is adjusted to 5 mm to 20 mm.

[0079] In step six, the output power of the pulse induction heating device 22 is adjusted within the range of 5kW to 60kW. Each function switch sequentially executes the following actions: the current function module stops working, the current function module retracts, the locking element 41 is released, the selection element 45 is switched, the target function module extends, and the locking element 41 is relocked. When the locking element 41 does not confirm that the target function module is in place, the arc power supply 34 and the pulse power supply 27 remain prohibited from output.

[0080] Combination Figures 1 to 5 Description of embodiments of the present invention:

[0081] Using Ti-6Al-4V titanium alloy as an example material, the cavity can be pumped down to 3×10 -1 Pa to 5×10 -1 Pa is applied and argon purging is performed 2 to 3 times. The arc-starting distance between the tungsten electrode 9 and the raw material can be 1 mm to 3 mm, and the working distance can be adjusted to 5 mm to 20 mm after a stable arc is formed. After one melting is completed, the ingot is flipped using the flipping spoon module 10 and the melting is repeated. After the last melting, the pulse induction heat treatment stage is entered. The output power of the pulse power supply 27 can be adjusted within the range of 5 kW to 60 kW; in one example, the power during the holding stage is about 15 kW, and the specific value is determined according to the temperature field, the conductivity target, and the rated capacity of the equipment.

[0082] The three-in-one multi-functional probe 3, with its infrared detector head 14 and infrared transmission protective window 15, forms a thermal imaging module 13. This module continuously records the temperature distribution changes during the solidification process of the molten metal and feeds the data back to the computer 28. This configuration enables non-contact, real-time temperature monitoring of the Ti-6Al-4V alloy melting and solidification process, avoiding interference from traditional temperature measurement methods on the molten pool state. Simultaneously, it acquires the temperature field variation patterns of the molten metal, providing data support for temperature control and microstructure evolution analysis during heat treatment, thus improving the controllability and stability of the material preparation process.

[0083] The preparation method of this embodiment includes the following steps:

[0084] Step 1: Before operation, the equipment needs to be inspected, including the water-cooled copper crucible 17, the three-in-one multi-functional probe 3, the vacuum system 35, and the water-cooling system 40. Ensure all switches and valves are closed. Check that the power adjustment knob is at zero and confirm that the argon cylinder 38 and other gas sources are in good working order.

[0085] Step 2: After opening the vent valve to restore the furnace pressure to atmospheric pressure, raise the furnace lid and place the alloy material to be melted into the water-cooled copper crucible 17. To facilitate smoother arc ignition later, one sample can be placed slightly higher than the others. After loading, lower and lock the furnace lid to ensure the furnace is completely sealed, preparing for subsequent vacuuming.

[0086] Step 3: Turn on the main power and start the vacuum pump. Open the corresponding valves to evacuate the furnace body, reducing the internal pressure to 3×10⁻⁶. -1 -5×10 -1 Pa is used to eliminate the interference of air inside the furnace on the smelting process.

[0087] Step 4: Evacuate the vacuum melting chamber (1) and fill it with protective gas to a positive pressure state, then start the vacuum pump again to extract the gas. This "vacuuming-argon filling" cycle usually needs to be repeated two to three times to remove the residual air in the furnace to the maximum extent, and finally keep the furnace under an argon protective atmosphere to prevent the alloy from oxidizing during the melting process.

[0088] Step 5: By switching component 7, the arc gun module 8 is put into the working position. Press the corresponding pressing end of the selection component 45, which drives the sliding push rod 43 to move axially along the guide frame 44. The small displacement of the pressing end is converted into a larger displacement of the tool end through the gear and rack extension mechanism. When the arc setting is selected, the arc gun module 8 drives the tungsten electrode 9 to extend downward to perform arc melting on the raw material. After melting is completed, the arc gun module 8 is retracted to ensure uniform alloy composition. By switching component 7, the flipping spoon module 10 is put into the working position. The angle drive motor 47 adjusts the angle of the flipping spoon module 10 to flip or stir the ingot. Then the flipping spoon module 10 is retracted. Usually, the sample needs to be flipped and melted three to four times.

[0089] Step Six: Using the operating lever 6, the thermal imaging module 13 is positioned to acquire the time-series data of the temperature field of the melt or ingot. The temperature data is processed by the image preprocessing module 30, and the conductivity prediction module 31 outputs the conductivity estimate. The control decision module 32 generates a control quantity based on the deviation between the conductivity target value and the conductivity estimate. The pulse controller 33 controls the pulse induction heating device 22 accordingly until the conductivity target range is reached or the preset heat treatment time is reached, thus completing the preparation of the resistive functional material and the monitoring of conductivity changes.

[0090] Step 7: After melting, do not open the furnace immediately. Maintain the furnace atmosphere to allow the sample to cool naturally to room temperature. After the sample has cooled sufficiently, open the vent valve and raise the furnace lid. Use a special tool to remove the finished alloy casting. Then, thoroughly clean the surface of the water-cooled copper crucible 17 and the vacuum melting chamber 1 with degreased cotton gauze soaked in anhydrous ethanol. Finally, close all valves, vacuum pumps, gas sources, and cooling water, and restore the equipment to its initial state to complete the entire operation.

[0091] This embodiment achieves precise control over the alloy heating, holding, and solidification processes by applying pulsed induction heating with different power, frequency, and duration during alloy melting and heat treatment. This facilitates the study of the effects of different heat treatment parameters on the microstructure evolution, resistivity changes, and electrical conductivity properties of the Ti-6Al-4V alloy.

[0092] This invention integrates an electric arc gun, a material-turning spoon, and a thermal imager into a single probe, and directly embeds a pulse induction heat treatment device into the electric arc melting process, thus constructing an integrated melting and heat treatment process. It utilizes a thermal imager for non-contact, full-field, real-time monitoring of the spatiotemporal evolution of the material's surface thermal conductivity. Combined with a machine learning model, it infers changes in electrical conductivity from dynamic thermal conductivity data, and then uses a computer to calculate electromagnetic shielding effectiveness online. This closed-loop intelligent system solves key problems inherent in traditional methods, such as the deterioration of microstructure and lengthy processes caused by the separate melting and heat treatment steps, the inability to perceive thermal and electrical conductivity online, the difficulty in accurately modeling the electrothermal transport relationships of complex alloys, the inability to detect shielding effectiveness offline and provide real-time process guidance, the reliance on inefficient trial-and-error iterations for high-performance shielding material development, and the inability to evaluate the shielding performance of irregularly shaped components online, coupled with high energy consumption.

[0093] Combining Figure 4(a) and Figure 4(b), Figure 5 This invention demonstrates the following effects: In the microstructure of Ti-6Al-4V alloy subjected to pulsed induction heating for two hours, the grain size was large, the microstructure was unevenly distributed, and there were obvious lamellar structures and wrinkled deformation areas in some regions. Grain boundary features were indistinct, and the internal microstructure continuity was poor. With the application of pulsed induction heating, the microstructure of the Ti-6Al-4V alloy changed significantly. The grain morphology was adjusted, the originally coarse microstructure gradually became finer, and the lamellar structure became more uniformly distributed. Monitoring the change in electrical conductivity of the Ti-6Al-4V alloy after six hours of heat treatment revealed that the initial electrical conductivity of the untreated sample was approximately 5.8 × 10⁻⁶. 5 With increasing heat treatment time, the conductivity decreased sequentially to 5.5 × 10⁻⁶ S / m. 5 S / m, 5.1×10 5 S / m and 4.7×10 5 S / m. This change indicates that pulsed induction heating can effectively regulate the internal microstructure of the alloy, causing changes in lattice distortion, defect state, and second-phase distribution, enhancing electron scattering, thereby achieving an increase in resistivity and continuous control of conductivity.

[0094] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control, comprising a device body, characterized in that: It also includes a three-in-one multi-functional probe (3). The three-in-one multi-functional probe (3) includes a probe housing and a switching component (7), an arc gun module (8), a material flipping spoon module (10), and a thermal imaging module (13) disposed therein. The thermal imaging module (13) is vertically fixed in the middle of the probe housing, and the arc gun module (8) and the flipping spoon module (10) are respectively disposed on both sides of the thermal imaging module (13); the switching component (7) is used to selectively move the arc gun module (8) or the flipping spoon module (10) from the retracted position to the working position, and keep the other unselected module in the retracted position. The thermal imaging module (13) remains unchanged in position during the tool module switching process. The switching component (7) is disposed within the probe housing. The switching component (7) includes a selector (45), a guide frame (44), a sliding push rod (43), a reset component (42), and a locking component (41). The guide frame (44) is fixedly disposed within the probe housing, with its lower part located within the probe housing. The sliding push rod (43) is axially slidably disposed within the guide frame (44). The arc gun module (8) and the material-turning spoon module (10) are respectively installed at the lower ends of the corresponding sliding push rods (43). The selector (45) is slidably disposed on the upper part of the guide frame (44) for driving the corresponding sliding push rod (43) to move from the retracted position to the working position along the guide frame (44); the reset member (42) acts on each sliding push rod (43) to restore the sliding push rod (43) from the working position to the retracted position; the locking member (41) is disposed between the guide frame (44) and the sliding push rod (43) for locking the sliding push rod (43) that has extended to the working position and for restricting two or more sliding push rods (43) from extending at the same time.

2. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control as described in claim 1, characterized in that: The switching component (7) also includes a range extender gear set (49) respectively set on both sides of the arc gun module (8) and the flipping spoon module (10). Each range extender gear set (49) includes an output rack, a pinion and a gear that are coaxially fixedly connected. The selector (45) drives the input rack to move. The input rack meshes with the pinion, and the gear that is coaxially connected with the pinion meshes with the output rack. The pitch circle radius of the gear is greater than that of the pinion, so that the moving distance of the sliding push rod (43) is greater than the pressing distance of the selector (45).

3. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control as described in claim 1, characterized in that: The three-in-one multi-functional probe 3 is fixed to the top cover (2) of the cavity by a bellows sealing assembly (5). The bellows sealing assembly (5) is used to maintain a vacuum seal during lifting, rotating or swinging operations. The power supply conductor of the arc gun module (8) passes through the bellows sealing assembly (5) through an insulating power feeder. The thermal imaging module (13) is connected to the image acquisition module (29) through a signal feeder (16).

4. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control as described in claim 1, characterized in that: The arc gun module (8) includes a tungsten electrode (9), an electrode holder, and a ceramic insulating sleeve; The material-turning spoon module (10) includes a spoon handle (11) and a spoon head (12) disposed at the lower end of the spoon handle (11). The spoon head (12) is made of high-temperature resistant metal or high-temperature resistant ceramic. The arc gun module (8) and the material-turning spoon module (10) are respectively connected to a rotary drive motor (47). The rotary drive motor (47) is used to drive the corresponding tool module to rotate around its axis to adjust the working angle of the tungsten electrode (9) or the spoon head (12) relative to the melting groove (18). The thermal imaging module (13) includes an infrared detector (14) and an infrared transmission protective window (15) located on the front side of the infrared detector (14). The field of view of the infrared detector (14) covers the melt or ingot area inside the water-cooled copper crucible (17).

5. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control according to claim 4, characterized in that: The thermal imaging module (13) also includes a protective shutter (46). When the arc gun module (8) is in the arc-starting state or the arc intensity exceeds the set threshold, the protective shutter (46) is closed. When entering the temperature measurement or pulse induction heat treatment stage, the protective shutter (46) is opened.

6. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control according to claim 1, characterized in that: The main body of the equipment includes a vacuum melting chamber (1), a water-cooled copper crucible (17) disposed in the vacuum melting chamber (1), a vacuum system (35) and a water cooling system (40) connected to the vacuum melting chamber (1), an arc power supply (34) electrically connected to the arc gun module (8), a pulse induction heating device (22) disposed on the outer periphery of the water-cooled copper crucible (17), a pulse power supply (27) electrically connected to the pulse induction heating device (22), and an intelligent control system; The intelligent control system includes an image acquisition module (29), an image preprocessing module (30), a conductivity prediction module (31), a control decision module (32), and a pulse controller (33) installed in a computer (28). The conductivity prediction module (31) is used to input the temperature field time series data acquired by the thermal imaging module (13) into a pre-trained conductivity prediction model and output the conductivity estimate of the processed material. The control decision module (32) generates a control quantity based on the deviation between the conductivity estimate and the target value, and adjusts the pulse power supply (27) through the pulse controller (33). The image preprocessing module (30) is used to perform correction processing on the temperature field time series data and extract the maximum temperature, average temperature, temperature gradient, heating rate, and cooling rate features from the processed temperature field time series data.

7. The resistive material arc melting and pulse induction heat treatment equipment based on a three-in-one probe and conductivity closed-loop control according to claim 6, characterized in that: The conductivity prediction model (31) is obtained by machine learning, and the conductivity reference value is obtained by the four-probe method, eddy current method or conductivity retest after cooling; the conductivity prediction model (31) is a support vector regression model, random forest model, gradient boosting model, artificial neural network model, convolutional neural network model, long short-term memory network model or a combination thereof.

8. The device for arc melting and pulse induction heat treatment of resistive materials based on a three-in-one probe and closed-loop conductivity control according to claim 1, characterized in that: The pulse induction heating device (22) is disposed on the outer periphery of the water-cooled copper crucible (17) and includes multiple stacked winding units (25) stacked and wound along the axial direction of the water-cooled copper crucible (17). The multiple stacked winding units (25) form an upper coil segment (23) and a lower coil segment (24). The equivalent winding thickness of the upper coil segment (23) is greater than the equivalent winding thickness of the lower coil segment (24). The equivalent winding thickness is the total radial dimension formed by the radial dimension of the conductor, the number of radial stacking layers, and the insulation gap between adjacent conductors in the corresponding coil segment. The upper coil segment (23) The ratio of the equivalent winding thickness of the upper coil segment (23) to the lower coil segment (24) is 1.1:1 to 3:1, and the axial turn density of the upper coil segment (23) is not less than the axial turn density of the lower coil segment (24); the upper coil segment (23) and the lower coil segment (24) are respectively provided with independent electrical connection terminals, and the pulse controller (33) can adjust the current amplitude and pulse frequency of the upper coil segment (23) and the lower coil segment (24) respectively; each stacked winding unit (25) is wound with a rectangular cross-section hollow copper conductor or insulated stranded conductor, and is separated from the water-cooled copper crucible (17) by an insulating support layer (26).

9. A method for preparing and monitoring resistive materials using an arc melting and pulse induction heat treatment apparatus based on a three-in-one probe and conductivity closed-loop control, as described in any one of claims 1 to 8, characterized in that: Includes the following steps: Step 1: Check the water-cooled copper crucible (17), the three-in-one multi-functional probe (3), the vacuum system (35) and the water-cooling system (40), confirm that the switches and valves of each part are closed, the power adjustment knob is set to zero, and confirm that the gas source is in good condition; Step 2: After opening the vent valve to restore the pressure inside the furnace to atmospheric pressure, raise the furnace cover and put the alloy material to be melted into the water-cooled copper crucible (17). After the material is loaded, lower the furnace cover and lock it. Step 3: Turn on the main power and start the vacuum pump. Open the corresponding valves to evacuate the furnace body and reduce the gas pressure inside the furnace to 3×10⁻¹Pa to 5×10⁻¹Pa. Step 4: Evacuate the vacuum melting chamber (1) and fill it with protective gas to a positive pressure state. Then start the vacuum pump again to extract the gas. Repeat the vacuuming and argon filling cycle 2 to 3 times to keep the furnace under a protective atmosphere. Step 5: By switching component (7), the arc gun module (8) is put into the working position, and the tungsten electrode (9) extends downward to perform arc melting on the raw material. After melting is completed, the arc gun module (8) is retracted. By switching component (7), the tilting spoon module (10) is put into the working position, and the corner drive motor (47) adjusts the angle of the tilting spoon module (10) to flip or stir the ingot. Then the tilting spoon module (10) is retracted, and the melting is repeated three to four times. Step 6: The image acquisition module (29) acquires the time-series data of the temperature field of the melt or ingot through the thermal imaging module (13), the image preprocessing module (30) processes the temperature data, and the conductivity prediction module (31) outputs the conductivity estimate. The control decision module (32) generates a control quantity based on the deviation between the conductivity target value and the conductivity estimate. The pulse controller (33) controls the pulse induction heating device (22) accordingly until the conductivity target range is reached or the preset heat treatment time is reached, thus completing the preparation of the resistive functional material and the monitoring of conductivity changes. Step 7: Maintain the atmosphere inside the furnace to allow the sample to cool naturally to room temperature. After the sample has cooled sufficiently, open the vent valve and raise the top cover of the cavity (2). Take out the finished alloy casting, clean the surface of the water-cooled copper crucible (17) and the vacuum melting cavity (1), and close all valves, vacuum pumps, gas sources and cooling water.

10. The method for preparing and monitoring resistivity materials according to claim 9, characterized in that: In step five, the arc-starting distance between the tungsten electrode (9) and the raw material is 1mm to 3mm. After a stable arc is formed, the working distance is adjusted to 5mm to 20mm. In step six, the output power of the pulse induction heating device 22 is adjusted within the range of 5kW to 60kW. Each function conversion sequentially executes the following actions: the current function module stops working, the current function module retracts, the locking element (41) is released, the selection element (45) is switched, the target function module extends, and the locking element (41) is relocked. When the locking element (41) does not confirm that the target function module is in place, the arc power supply (34) and the pulse power supply (27) remain prohibited from output.

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