Regulation and control method for electrical contact performance of pivot rail of electromagnetic rail launching device

Abstract

The invention belongs to the technical field of electromagnetic rails, and relates to a method for regulating and controlling the electrical contact performance of a pivot rail of an electromagnetic rail launching device, which comprises the following steps of: 1, carrying out grinding and polishing pretreatment on the surface of a copper-based material to form a mirror surface; 2, the pretreated copper-based material is subjected to surface cleaning through ultrapure water and ethyl alcohol in sequence, and drying treatment is conducted; 3, dissolving an alkane polymer in an organic solvent to prepare a mixed solution; 4, the surface of the pretreated copper-based material is coated with the prepared mixed solution, and the alkane polymer coating is prepared through drying and curing; according to the method, alkane polymer modification is carried out on the surface of the copper-based material by controlling the components, the concentration and the coating thickness of the mixed solution, the surface temperature of an interface is reduced, the contradictory problem of high conductivity and surface ablation abrasion of a pivot rail sliding conductive contact surface is solved, and therefore the service life of an electromagnetic rail is prolonged.

Description

Technical Field

[0001] This invention belongs to the field of electromagnetic track technology, specifically relating to a method for controlling the electrical contact performance of the pivot rail of an electromagnetic track launching device. Background Technology

[0002] Electromagnetic railguns are devices that use the Ampere force generated by the electromagnetic field in an electromagnetic system to accelerate metal projectiles. They possess advantages such as high energy, high precision, long range, and high destructive power. Their structure consists of two parallel fixed rails and an armature that maintains good electrical contact with the rails and can slide along the rail axis. During electromagnetic launch, the armature-rail contact surface operates in a harsh environment of electromagnetic and thermal field coupling and extreme impact. Even with high-precision machining of the metal surface, the non-tight contact conductivity at the contact surface is still achieved through localized electrical contact, with the actual contact area being much smaller than the nominal contact area. The current density at the contact point is extremely high, resulting in significant contact resistance. Typically, increasing the pressure can increase the contact area at the connection point, reducing resistance and surface effects. However, electromagnetic railguns require ultra-high-speed armature movement, and increasing the contact pressure would significantly increase contact resistance. Therefore, the contradiction between high conductivity and frictional resistance severely hinders the engineering application of such high-current sliding conductive devices.

[0003] Currently, to mitigate armature contact ablation, one approach is to improve machining precision and increase contact pressure, but this increases the frictional resistance of armature movement, affecting its speed. Another approach is to select ablation-resistant and wear-resistant materials and improve the mechanical strength of electrode materials or hard metal coatings, but this increases circuit resistance, and arc erosion in the contact gap is unavoidable, sometimes even leading to a reduction in the actual contact area and more severe ablation. The contact sliding conductivity between electrodes is a key factor in obtaining higher electromagnetic driving force; the methods described above cannot resolve the contradiction between high conductivity and surface ablation / wear between the sliding conductive contact surfaces. Summary of the Invention

[0004] This invention aims to solve the technical problem of the contradiction between high conductivity and surface ablation wear between sliding conductive contact surfaces by changing the electrical contact between electrodes from a "point connection" to a "gas-conducting surface connection". Its special feature is as follows: Figure 1The principle behind the pivot-orbit electrical contact performance modulation method is as follows: When the carbon-hydrogen bonds in alkanes homolytically cleave, a hydrogen radical and an alkyl radical (carbon radical) are generated. The three sp hybrid orbitals of carbon have a planar triangular structure. Each sp hybrid orbital overlaps with the orbitals of other atoms along the axis to form a σ bond. The bonding orbital has a pair of electrons with opposite spins, and a p orbital perpendicular to this plane is occupied by a lone electron. The cleavage and ionization process is inevitably affected by an external magnetic field. Under the influence of high-temperature plasma, the cleavage and ionization process of alkanes can generate as many small molecules, hydrogen radicals, carbon radicals, electrons, and charged particles as possible, forming an effective high-conductivity channel, thereby enhancing the interstitial conductivity.

[0005] This invention provides the following technical solution: a method for controlling the electrical contact performance of the pivot rail of an electromagnetic orbital launch device, comprising the following steps:

[0006] Step 1: Grind and polish the surface of the copper-based material to form a mirror finish;

[0007] Step 2: Clean the surface of the pretreated copper-based material sequentially with ultrapure water and ethanol, and then dry it.

[0008] Step 3: Dissolve the alkane polymer in an organic solvent to prepare a mixed solution;

[0009] Step 4: Coat the prepared mixed solution onto the surface of the pretreated copper-based material, and then dry and cure it to obtain the alkane polymer coating.

[0010] Preferably, in step 1, the copper-based material includes brass, copper, or copper-chromium-zirconium alloy.

[0011] Preferably, in step 2, the drying process includes: forced air drying, vacuum drying, or air drying.

[0012] Surface cleaning methods for copper-based materials include: ultrasonic cleaning, lint-free paper wiping, and lint-free cotton wiping.

[0013] Preferably, in step 3, the alkane polymer is an open-chain saturated hydrocarbon, and is a n-alkane;

[0014] Organic solvents include: ethanol, petroleum ether, polymethyl methacrylate, acetone, carbon tetrachloride, or diethyl ether.

[0015] More preferably, the alkane polymer includes one or more of docosane, tetracosane, octacosane, docosane, hexacosane, tetracosane, hexacosane, and pentacosane.

[0016] More preferably, the petroleum ether comprises: high-boiling-point petroleum ether with a temperature of 60–90°C or 90–120°C.

[0017] Preferably, in step 3, the concentration of the mixed solution is 5–30 mg / mL.

[0018] Preferably, in step 4, the coating method of the mixed solution coating includes coating the surface of the copper-based material using a spin coater and / or an airbrush.

[0019] The present invention also discloses a copper-based material with alkane polymer surface modification, wherein the copper-based material is prepared by the above-mentioned method for controlling the pivot rail electrical contact performance of an electromagnetic orbital launch device.

[0020] Preferably, the copper-based material is used for multi-physics field coupled current-carrying friction.

[0021] The beneficial effects of this invention are:

[0022] 1. The long-chain alkane polymer of the present invention is a common phase change material. Under the action of interfacial frictional heat effect, the coating can be rapidly liquefied and has good wetting properties with the track metal, which can quickly fill the gap between the armature and the track. As the temperature rises, the liquefied coating vaporizes in the high-temperature region, which not only helps to absorb local heat and reduce the surface temperature at the interface, but also can quickly remove the air in the gap and reduce the oxidative corrosion of the track by oxygen in the air.

[0023] 2. Under the action of electric arc plasma, the alkane polymer will undergo cracking and ionization, generating a large number of small molecules, electrons and charged particles, forming an effectively extended conductive channel, alleviating the concentration of electric arc energy, reducing track ablation, and ensuring good conductivity between the contact surfaces during sliding without increasing contact pressure, thus overcoming the contradiction between high conductivity and surface ablation wear of the pivot track sliding conductive contact surface.

[0024] 3. The preparation method of the present invention is simple and feasible, and the preparation cycle is short. It is mainly reflected in the fact that alkane polymer coatings can be prepared by simple dissolution, coating, drying and curing. Attached Figure Description

[0025] Figure 1 This is a schematic diagram illustrating the principle of alkane polymer pyrolysis and ionization to enhance gap conductivity in a method for regulating the electrical contact performance of the pivot rail of an electromagnetic orbital launch device according to the present invention.

[0026] Figure 2 This is a comparison chart of the gap resistance under a peak breakdown current of 37A obtained in Embodiment 1 and Comparative Example 1 of the present invention.

[0027] Figure 3 This is a comparison chart of the ablation amount of copper-based materials after vacuum arc ablation obtained in Embodiment 1 and Comparative Example 1 of the present invention;

[0028] Figure 4This is a vacuum arc ablation SEM image of the copper-based material obtained in Comparative Example 1 of the present invention.

[0029] Figure 5 The image shows a vacuum arc ablation SEM image of the copper-based material modified with alkane polymer obtained in Example 1 of this invention.

[0030] Figure 6 This is a comparison chart of contact resistance under a 3600A pulse current obtained in Embodiment 2 and Comparative Example 1 of the present invention;

[0031] Figure 7 This is a diagram showing the phase transition and interstitial gas discharge effect of the alkane polymer obtained in Example 2 of the present invention;

[0032] Figure 8 These are comparison images of the wear of the simulated electromagnetic rail launch armature obtained in Embodiment 3 and Comparative Example 2 of the present invention.

[0033] Figure 9 These are comparison images of simulated electromagnetic rail launch track wear obtained in Embodiment 3 and Comparative Example 2 of the present invention;

[0034] Figure 10 Schematic diagrams of spin coating (a) and spray coating (b) of a uniformly mixed solution provided in embodiments of the present invention;

[0035] Figure 11 A flowchart of a method for regulating the electrical contact performance of the pivot rail of an electromagnetic rail launcher is provided for embodiments of the present invention. Detailed Implementation

[0036] The related technologies of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0037] like Figures 1-11 As shown, the method for controlling the pivot rail electrical contact performance of the electromagnetic rail launcher in this embodiment includes the following steps:

[0038] Step 1: Grind and polish the surface of the copper-based material to form a mirror finish;

[0039] Step 2: Clean the surface of the pretreated copper-based material sequentially with ultrapure water and ethanol, and then dry it.

[0040] Step 3: Dissolve the alkane polymer in an organic solvent to prepare a mixed solution;

[0041] Step 4: Coat the mixed solution prepared in step 3 onto the surface of the pretreated copper-based material, and then dry and cure it to obtain the alkane polymer coating.

[0042] Furthermore, the copper-based material is any one of brass, copper, or copper-chromium-zirconium alloy.

[0043] Furthermore, the drying process can be any one of blower drying, vacuum drying, or air drying.

[0044] Furthermore, the surface cleaning method of the copper-based material is any one or a combination of ultrasonic cleaning, lint-free paper wiping, and lint-free cotton wiping.

[0045] Furthermore, the alkane polymer is an open-chain saturated hydrocarbon, all of which are n-alkanes.

[0046] Furthermore, the alkane polymer is one or more of docosane, tetracosane, octacosane, docosane, hexadecane, tetradecane, tetradecane, hexadecane, and pentadecane.

[0047] Furthermore, the organic solvent is any one of ethanol, petroleum ether, acetone, carbon tetrachloride, or diethyl ether.

[0048] Furthermore, the petroleum ether organic solvent is a high-boiling-point petroleum ether with a temperature of 60–90°C or 90–120°C.

[0049] Furthermore, the concentration of the solution is 5–30 mg / mL.

[0050] Furthermore, the coating method is to use a spin coater / airbrush for spin coating / spraying.

[0051] Example

[0052] Example 1: Surface modification of alkane polymers to enhance the interstitial conductivity and ablation resistance of copper-based materials

[0053] 1) Grind and polish the circular copper-based composite materials with diameters of 10mm and 28mm to form a mirror effect, then place them in ultrapure water and ethanol in sequence, ultrasonically clean for 10 minutes, and let them air dry naturally.

[0054] 2) Dissolve 30 mg of n-tetracosane in 1 mL of petroleum ether and sonicate at room temperature for 10 min to obtain a homogeneous mixed solution.

[0055] 3) Using a spin coater, the mixed solution prepared in step 2 was spin-coated onto the surface of the copper-based material at 3000 RPM and 10 s. The material was then placed in the air to air dry and cure, resulting in a copper-based metal electrode modified with an alkane polymer coating.

[0056] 4) The modified copper-based metal electrode was subjected to vacuum arc ablation experiment in an arc plasma characteristic experimental device.

[0057] Example 2: Surface modification of alkane polymers to enhance the electrical conductivity of copper-based materials.

[0058] 1) Grind and polish the circular copper-based composite materials with diameters of 28mm and 10mm to form a mirror effect, then place them in ultrapure water and ethanol in sequence, ultrasonically clean for 10 minutes, and let them air dry naturally.

[0059] 2) Dissolve 30 mg of n-octacosanane in 1 mL of petroleum ether and sonicate at 25 °C for 10 min to obtain a homogeneous mixed solution.

[0060] 3) Using a spin coater, the mixed solution prepared in step 2 was spin-coated onto the surface of the copper-based material at 3000 RPM and 10 s. The material was then placed in the air to air dry and cure, resulting in a copper-based metal electrode modified with an alkane polymer coating.

[0061] 4) The modified copper-based metal electrode was tested for electrical contact performance using a pulse current contact resistance measuring device.

[0062] Example 3: Surface modification of alkane polymers to enhance the electrical contact performance of electromagnetic rail launchers.

[0063] 1) Grind and polish the 1500×20×5mm brass and copper-chromium-zirconium track.

[0064] 2) Wipe the pre-treated copper-based track polished surface with lint-free paper and alcohol to remove surface grease and other contaminants, and then let it air dry naturally.

[0065] 3) Dissolve 150 mg of n-tetracosane in 5 mL of petroleum ether and sonicate at 25 °C for 10 min to obtain a homogeneous mixed solution.

[0066] 4) Using an airbrush, spray the mixed solution prepared in step 3 onto the polished surfaces of the brass track and the copper-chromium-zirconium track, place it in the air, let it air dry and cure naturally, and obtain the brass track electrode modified with alkane polymer coating.

[0067] 5) The modified brass and copper-chromium-zirconium rail electrodes were tested for electrical contact performance in a simulated electromagnetic rail launcher.

[0068] Comparative Example 1:

[0069] 1) Grind and polish circular copper-based composite materials with diameters of 10mm and 28mm to create a mirror finish.

[0070] 2) The pretreated copper-based composite material was placed in ultrapure water and ethanol in sequence, ultrasonically cleaned for 10 minutes, and then air-dried.

[0071] 3) The cleaned copper-based metal electrode from step 2 was subjected to a vacuum arc ablation experiment in an arc plasma characteristic experimental device.

[0072] 4) The cleaned copper-based metal electrode from step 2 is subjected to electrical contact performance testing using a pulse current contact resistance measuring device.

[0073] Comparative Example 2:

[0074] 1) Grind and polish the 1500×20×5mm brass and copper-chromium-zirconium track.

[0075] 2) Wipe the pre-treated copper-based track polished surface with lint-free paper and alcohol to remove surface grease and other contaminants, and then let it air dry naturally.

[0076] 3) The surface-cleaned brass and copper-chromium-zirconium rail electrodes were tested for electrical contact performance in a simulated electromagnetic rail launcher.

[0077] from Figure 2 It can be seen that in the vacuum arc ablation experiment, after the vacuum gap breaks down, the alkane polymer-modified copper-based metal electrode can generate more charged particles, effectively reducing the gap resistance and enhancing the gap conductivity.

[0078] from Figure 3 It can be seen that, under the influence of the endothermic phase transition of alkane and the improvement of interstitial conductivity, the surface-modified copper-based electrode material has a lower ablation rate.

[0079] from Figure 4 It can be seen that in the vacuum arc ablation experiment, the copper-based ablation pits in Comparative Example 1 have dense and large cathode spots.

[0080] from Figure 5 It can be seen that, in the vacuum arc ablation experiment, compared with Comparative Example 1, the copper-based metal electrode modified with alkane polymer in Example 1 has smaller and more dispersed cathode spots.

[0081] from Figure 6 It can be seen that in the pulse current contact resistance test, under multiple 3600A high current pulse inputs, the alkane-modified copper-based metal electrode has a smaller contact resistance.

[0082] from Figure 7 As can be seen, in the pulse current contact resistance test, in Example 2, the surface alkane polymer underwent a solid-liquid (gas)-solid phase change process, which eliminated some of the interstitial air, resulting in adhesion areas in the copper-based material.

[0083] from Figure 8 It can be seen that, in the simulated electromagnetic orbital launch test, compared with Comparative Example 2, the alkane polymer coating in Example 3 can effectively absorb local heat and reduce the erosion of the aluminum alloy armature.

[0084] from Figure 9 It can be seen that, in the simulated electromagnetic orbit launch test, compared with Comparative Example 2, the alkane polymer coating in Example 3 can play a wetting role, reduce frictional resistance, weaken the frictional wear between the pivot and the rail, and reduce aluminum deposition on the rail.

[0085] In summary, this invention modifies the surface of copper-based materials with alkane polymers by controlling the composition, concentration, and coating thickness of the mixed solution, thereby reducing the surface temperature at the interface and resolving the contradiction between high conductivity and surface ablation wear on the sliding conductive contact surface of the pivot rail, thus improving the service life of the electromagnetic rail. At the same time, the preparation method is simple and feasible, with a short preparation cycle, and has good prospects for application in multi-physics field coupled current-carrying friction conditions.

[0086] It should be emphasized that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. A method for controlling the electrical contact performance of the pivot rail of an electromagnetic orbital launcher, characterized in that, Includes the following steps: Step 1: Grind and polish the surface of the copper-based material to form a mirror finish; Step 2: Clean the surface of the pretreated copper-based material sequentially with ultrapure water and ethanol, and then dry it. Step 3: Dissolve the alkane polymer in an organic solvent to prepare a mixed solution; Step 4: Coat the prepared mixed solution onto the surface of the pretreated copper-based material, and then dry and cure it to obtain an alkane polymer coating.

2. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 1, characterized in that, In step 1, the copper-based material includes brass, copper, or copper-chromium-zirconium alloy.

3. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 1, characterized in that, In step 2, the drying process includes: forced air drying, vacuum drying, or air drying. The surface cleaning methods for the copper-based materials include: ultrasonic cleaning, wiping with lint-free paper, and wiping with lint-free cotton.

4. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 1, characterized in that, In step 3, the alkane polymer is an open-chain saturated hydrocarbon, and is a n-alkane; The organic solvents include: ethanol, petroleum ether, polymethyl methacrylate, acetone, carbon tetrachloride, or diethyl ether.

5. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 4, characterized in that, The alkane polymer includes one or more of docosane, tetracosane, octacosane, docosane, hexacosane, tetracosane, hexacosane, and pentane.

6. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 4, characterized in that, The petroleum ethers include high-boiling-point petroleum ethers with temperatures ranging from 60 to 90°C and 90 to 120°C.

7. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 1, characterized in that, In step 3, the concentration of the mixed solution is 5–30 mg / mL.

8. The method for controlling the pivot rail electrical contact performance of an electromagnetic rail launcher according to claim 1, characterized in that, In step 4, the coating method of the mixed solution coating includes coating the surface of the copper-based material using a spin coater and / or an airbrush.

9. A copper-based material with an alkane polymer surface modified, characterized in that, The copper-based material is prepared using the method for controlling the electrical contact performance of the pivot rail of the electromagnetic orbital launch device as described in any one of claims 1-8.

10. A copper-based material with alkane polymer surface modification according to claim 9, characterized in that, The copper-based material is used for multi-physics field coupled current-carrying friction.

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