A method for reconstructing the ablation morphology of the surface of an electromagnetic orbital launch hub.

Abstract

This invention relates to a method for reconstructing the ablation morphology of the armature surface in electromagnetic launch systems, belonging to the field of electromagnetic orbital launch technology. This invention allows for obtaining samples of the orbit and armature after actual launch under laboratory conditions, avoiding destructive disassembly of the electromagnetic launcher. Its cost and time efficiency are significantly improved compared to disassembly methods. The reconstruction process is simple, and the process is easy to operate and control. Furthermore, this invention can be used to conduct equivalent testing and verification of new armature-rail friction pair materials and surface treatment materials for future electromagnetic launches. Through improvements to the reconstruction device and the adoption of a strategy of first identifying the arc point, combined with the accumulation of non-contact ablation reconstruction data, this invention provides the necessary conditions for rapidly constructing a scientifically complete reconstruction database of the ablation morphology of the armature and orbital surfaces in electromagnetic orbital launch systems.

Description

Technical Field

[0001] This invention relates to a method for reconstructing the ablation morphology of the surface of an electromagnetic launch pivot rail; it belongs to the field of electromagnetic orbital launch technology. Background Technology

[0002] Electromagnetic orbital launch technology is a novel launch method that uses electromagnetic energy to propel objects at ultra-high speeds. Its launch tube structure consists of two parallel metal rails and a current-carrying armature in the middle. During launch, a pulsed current flows into one rail, passes through the central armature, and exits from the other rail. A strong magnetic field is formed between the parallel metal rails. Under the influence of this strong magnetic field, the central current-carrying armature generates a Lorentz force, thereby propelling the armature carrying the warhead out at high speed.

[0003] The launch process involves current-carrying friction between the armature and the track under extreme electromagnetic-thermal coupling conditions. During launch, due to the accumulation of frictional and Joule heat, the armature softens and its surface melts, transitioning from solid-solid contact to solid-liquid-solid contact, and finally to solid-liquid / arc-solid contact along the launch direction. During the sliding process between the armature and track, loss of contact can induce the generation of an electric arc. This arc can cause erosive damage to the surface of the armature-track friction pair, severely affecting the reliability and service life of the launcher.

[0004] Currently, common methods for testing the arc ablation of the pivot rail include actual launch tests and equivalent simulation methods. Actual launch tests are complex, time-consuming, and costly, making them unsuitable for studying the ablation properties of materials. Chinese patent document CN 117825259 A discloses an equivalent testing method for simulating the ablation of an electromagnetic railgun track. This method uses a supersonic plasma generator to produce plasma that is sprayed onto the surface of the rail sample, thereby obtaining the ablation morphology of the track surface. However, this method requires generating a large amount of plasma, resulting in high testing costs, and can only test the same workpiece, making it impossible to simultaneously obtain the surface ablation morphology of the pivot rail friction pair and its corresponding characteristics. Chinese patent document CN116202366 A discloses a method for reconstructing the surface of an electromagnetic launch track. This patent reconstructs the arc ablation morphology by adjusting parameters such as contact pressure, friction speed, current density, and arc initiation distance. However, the friction pair experiences friction in the early stages of the reconstruction process, and the arc erosion during the arc initiation process may cause the Al alloy to melt, increasing the arc initiation distance between the Cu alloy and the Al alloy, making it impossible to guarantee a long arc initiation process. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies. Building upon the original patent for track surface reconstruction, further research revealed that during the mid-to-late stages of electromagnetic track launch armature development, melting and softening of the armature surface may lead to a loss of contact between the armature and the track. To better and more quickly conduct a systematic study of this state, the technology described in this invention was developed.

[0006] This invention reconstructs the ablation morphology of the rear section surface of the electromagnetic rail launch pivot material by adjusting the arc initiation test process. It can also be used to test the ablation resistance of the pivot friction pair surface after treatment (such as coating with an anti-ablation coating).

[0007] This invention also addresses the shortcomings of existing technologies by improving the pin-disc type current-carrying friction device. A new arc-starting point search step is added to avoid the wear process in the early stage of arc-starting. Furthermore, the arc-starting process can ensure that the armature material and the track material do not come into contact and are controlled within a reasonable range, thereby enabling a longer arc-starting test process.

[0008] This invention aims to provide a reasonable, low-cost, and easily controllable method that can reconstruct the ablation microstructure of the pivot-rail friction pair surface at different launch frequencies and locations by changing parameters such as current magnitude and arc initiation time. This provides ample research samples for the ablation damage process of electromagnetic orbital launch pivot-rail friction pair materials, guiding the development of novel high-performance pivot-rail friction pair materials and surface treatment processes. Furthermore, this invention allows for the testing of the ablation resistance of novel pivot-rail friction pair materials and materials with different surface treatments.

[0009] This invention uses electromagnetic orbital launch armature material and track material as reconstructed raw materials, and adopts an improved pin-disc type current-carrying friction device. By setting different parameters such as current magnitude and ablation time, and by adding functions such as finding the initial arc starting point and controlling the ablation distance, the ablation structure of the track surface under different launch times can be obtained. It can also test the ablation resistance of different armature and track materials.

[0010] This invention discloses a reconstruction method for an electromagnetic track launch armature and track surface ablation. The reconstruction device used is an improved version of a current-carrying friction testing machine, comprising a disc sample, a pin sample, a power supply system, and a high-precision electric cylinder. The pin sample is connected to a pin sample fixture via an insulating layer, and the pin sample fixture is connected to the high-precision electric cylinder. During operation, the high-precision electric cylinder pushes the pin sample fixture, causing the pin sample to move at a set speed and trajectory. The pin sample is connected to the power supply system via a wire. After the reconstruction device is assembled, there is a gap between the disc sample and the pin sample. The disc sample is connected to a rotary drive device, allowing the disc sample to be either stationary or rotate at a set speed, depending on requirements.

[0011] The reconstruction method includes the following steps:

[0012] Step 1: Find the starting point of the arc

[0013] The circuit current loading power supply is turned on, and the power supply provides current. The pin sample is driven by a high-precision electric cylinder to approach the disc sample at a set speed. At this time, the disc sample is stationary. When the pin sample and the disc sample reach the arc-starting distance, an electric arc is generated. At this time, the circuit detects that current is passing through it. The system locates the position, and the electric cylinder drives the pin sample to retract. The arc-starting point is found.

[0014] Step 2 Arc Initiation Test

[0015] Set the arc ignition current, arc ignition time, and disc sample rotation speed, and begin the arc ignition test. Once the disc sample stabilizes at the set rotation speed, the electric cylinder moves the pin sample to the arc ignition point, and the arc ignition test begins. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. Repeat the arc ignition test until the current in the circuit reaches the set ablation time. Then, the current loading power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position. The arc ignition test is completed. During the arc ignition test, there is a gap between the disc sample and the pin sample.

[0016] During the arc initiation test, there is a gap between the disk sample and the pin sample. This is done in two ways: firstly, to maintain the continuous generation of the arc, and secondly, to avoid the ablation morphology reconstructed by the frictional contact between the pin sample and the disk sample during the test, and to eliminate all interference caused by friction.

[0017] In practical applications, the ablation morphology of the electromagnetic launch armature and track surface is reconstructed based on the microstructure of the disk test and pin sample surface obtained from the experiment.

[0018] Due to variations in current magnitude (based on laboratory conditions and safety, a constant low-voltage power supply and a high-current system are used), the cross-sectional area of ​​the pin sample, and the state of the gas medium (including air), the arc initiation distance may differ in each arc ablation process. To address this, this invention incorporates an arc initiation point search step to locate the arc initiation position before the arc ablation test begins. This method of locating the arc initiation position before the test generates a small area of ​​ablation characteristics on the pin sample surface, which is beneficial for the generation and stable continuation of the arc during the ablation test. Furthermore, it allows the pin sample to be quickly moved to the test point during the test, saving test time.

[0019] The process of finding the arc initiation point is as follows: The power system provides current, at which point the disc sample is stationary. The high-precision electric cylinder drives the pin sample to approach the disc sample at a speed of 5-20 μm / s via the slide rail. When the pin sample and the disc sample generate an electric arc, the electrical circuit system detects the current flowing through them. At this time, the control system positions the arc initiation point, and the motor drives the pin sample back, completing the arc initiation point location search.

[0020] After locating the arc initiation point, set the arc initiation current, arc initiation time, and disc sample rotation speed. The motor drives the pin sample to the arc initiation point, and the arc initiation test begins. When the distance between the pin sample and the disc sample increases due to ablation, the circuit current disappears. The motor continues to drive the pin sample towards the disc sample at a set speed (e.g., 10 μm / s) until current is detected in the circuit again, and the arc continues to be generated. Repeat the above steps until the set arc initiation time is reached. Then, the circuit power is disconnected, the motor drives the pin sample back, the disc sample stops, and the arc initiation test is complete.

[0021] This invention uses a pin-disc friction device, which can greatly reduce the space and area required for experiments. Moreover, by employing corresponding experimental parameters (orders of magnitude smaller) than those used in existing electromagnetic rail launch technologies (especially electromagnetic guns), this invention can construct the ablation state of the pivot-rail friction pair under different launch cycles through the accumulation of ablation time, and obtain ablation samples of the pivot-rail friction pair surface with corresponding ablation characteristics.

[0022] This invention uses a pin-disc type current-carrying friction and wear device. Although the current density and speed of the reconstruction process are lower than those of the actual launch conditions, the use of a rotary ablation method allows the ablation degree of the disk sample and the pin sample to have a superimposed effect. By controlling the ablation current and ablation time, it is possible to achieve a reconstruction of the morphology of the actual armature and track surface under different launch times.

[0023] This invention discloses a reconstruction method for the electromagnetic track launch armature and track surface ablation, wherein two pin samples are provided; the ablation current in this invention is supplied by a constant voltage power supply system, and after being generated by the power supply system, the current flows into the disk sample from one pin and then flows out from the other pin sample. Figure 1 The disc sample has a diameter of 100-300 mm, and the pin sample is a cylinder with a diameter calculated from the required current density, ranging from 1-10 mm. In this invention, the disc sample is made of the same material as the track; the pin sample is made of the same material as the armature.

[0024] This invention discloses a method for reconstructing the electromagnetic track launch armature and track surface ablation. The device is an improved version of a current-carrying friction testing machine and comprises a disk sample, a pin sample, an external power supply, and a high-precision electric cylinder. Figure 1By adding an arc initiation point search step, the problem of arc initiation distance changes due to variations in current magnitude, sample size, and air medium is solved. Furthermore, the arc initiation distance can be maintained during ablation testing based on the detection of current in the circuit, enabling stable arc initiation testing over extended periods.

[0025] This invention discloses a reconstruction method for the ablation of the armature and track surface of an electromagnetic track transmitter. The method uses the track material as the disk sample material and the armature material as the pin sample material. The rotational speed of the disk sample is controlled at 0-3000 rpm, preferably 500-3000 rpm. The controlled current is 50-300 A, and the diameter of the controlled pin sample is 1-10 mm. The corresponding current density range during the arc initiation test is 6.37 × 10⁻⁶. 4 ~3.82×10 8 A / mm 2 The preferred value is 1.0×10 7 ~3.82×10 8 A / mm 2 In this invention, such a high current density is used to more easily induce and maintain the stability of the electric arc. If it is too low, it will lead to problems such as difficulty in arc initiation and insignificant reconstruction effect; if it is too high, it will lead to problems such as the pin sample melting too quickly, the distance between the pin sample and the disc sample increasing, and the inability to maintain the electric arc for a long time.

[0026] The present invention discloses a method for reconstructing an electromagnetic track launch armature and track surface ablation. Preferably, the track material is a CuCrZr alloy and the armature material is a 7075Al alloy.

[0027] Current research on the ablation of the pivot-rail friction pair surface primarily involves disassembling and analyzing the track after launch. However, due to the high exit velocity of the launching armature, the armature recovery efficiency is extremely low. This invention presents a method that can obtain samples of the actual launched track and armature under laboratory conditions, avoiding destructive disassembly of the electromagnetic launcher. This method significantly reduces cost and time compared to disassembly methods, simplifies the reconstruction process, and facilitates easy operation and control. Furthermore, this invention can be used to conduct equivalent testing and verification of novel pivot-rail friction pair materials and surface treatment materials for future electromagnetic launches. Attached Figure Description

[0028] Appendix Figure 1 This is a schematic diagram of an arc ablation device;

[0029] Appendix Figure 2 The image shows the ablation morphology of the orbital surface after 45 launches.

[0030] Appendix Figure 3 The image shows the ablation morphology of the orbital surface after 100 launches.

[0031] Appendix Figure 4 Image of the surface ablation morphology of the armature obtained from the 45th launch and recovery of the launch orbit;

[0032] Appendix Figure 5 The surface reconstruction image obtained in Example 1;

[0033] Appendix Figure 6 The surface reconstruction image obtained in Example 2;

[0034] Appendix Figure 7 This is a surface reconstruction image obtained in Comparative Example 1;

[0035] Appendix Figure 8 This is a surface reconstruction image obtained from Comparative Example 2. Detailed Implementation

[0036] In the embodiment, the schematic diagram of the arc ablation reconstruction device is as follows: Figure 1 As shown, the material of the disc sample is the same as that used for the track (specifically, CuCrZr alloy); the material of the pin sample is the same as that used for the armature (specifically, 7075Al alloy); and the diameter of the disc sample is 180 mm.

[0037] Step 1: Find the starting point of the arc

[0038] The circuit current loading power supply is turned on, and the power supply provides current. The pin sample is driven by a high-precision electric cylinder to approach the disc sample at a set speed. At this time, the disc sample is stationary. When the pin sample and the disc sample reach the arc-starting distance, an electric arc is generated. At this time, the circuit detects that current is passing through it. The system locates the position, and the electric cylinder drives the pin sample to retract. The arc-starting point is found.

[0039] Step 2 Arc Initiation Test

[0040] Set the arc ignition current, arc ignition time, and disc sample rotation speed, and begin the arc ignition test. Once the disc sample stabilizes at the set rotation speed, the electric cylinder moves the pin sample to the arc ignition point, and the arc ignition test begins. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. Repeat the arc ignition test until the current in the circuit reaches the set ablation time. Then, the current loading power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position. The arc ignition test is completed. During the arc ignition test, there is a gap between the disc sample and the pin sample.

[0041] Example 1

[0042] First, the diameter of the pin sample is machined to 10 mm. After locating the arc initiation point, the arc initiation current is set to 100 A (corresponding to a current density of 1.27 × 10⁻⁶). 6 A / m2 The disc sample rotates at 1500 rpm to initiate the arc ignition test. Once the disc sample stabilizes at the set speed of 1500 rpm, the electric cylinder moves the pin sample to the arc ignition point to begin arc ignition. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. The arc ignition test is repeated until the current in the circuit reaches the set ablation time (2 minutes in this embodiment). Then, the current loading power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position, completing the arc ignition test. During the arc ignition test, there is a gap between the disc sample and the pin sample. The ablation morphology of the disc sample and the pin sample is as follows. Figure 5 As shown in the image, the surface ablation morphology of the product obtained in Example 1 reveals some ablation pits and holes on the track surface. These are quite similar to the ablation pits in the ablation morphology image of the track surface after 45 launches. Combining the two, it can be seen that their ablation characteristics are similar, the area occupied is basically the same, and the pin sample surface shows a melt structure and ablation holes similar to the armature surface. Based on the above, it can be concluded that this example achieves ablation reconstruction of the armature and track surface after 45 launches.

[0043] Accumulating images of samples with different pin diameters, currents, rotation speeds, and durations provides the necessary conditions for subsequent reconstruction. Simultaneously, this invention can also scientifically reconstruct the influence of the ambient atmosphere on the electromagnetic track and armature.

[0044] Example 2

[0045] First, the diameter of the pin sample is machined to 2 mm. After locating the arc initiation point, the arc initiation current is set to 300 A (corresponding to a current density of 9.55 × 10⁻⁶). 7 A / m 2 The disk sample rotates at 500 rpm to initiate the arc ignition test. Once the disk sample stabilizes at the set speed of 500 rpm, the electric cylinder moves the pin sample to the arc ignition point to initiate the arc. When the distance between the pin sample and the disk sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disk sample until the arc reappears. The arc ignition test is repeated until the current in the circuit reaches the set ablation time (5 minutes in this embodiment). Then, the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder moves the pin sample away from the disk sample to the disassembly position. The arc ignition test is completed. During the arc ignition test, there is a gap between the disk sample and the pin sample, and its ablation morphology is as follows. Figure 6As shown in the image, the surface ablation morphology of the product obtained in Example 2 shows that the track surface is almost entirely covered with ablation pits and holes. These are quite similar to the ablation pits in the track surface ablation morphology image after 100 launches. Combining the two, it can be seen that their ablation characteristics are similar, the area occupied is basically the same, and the pin sample surface shows a melt structure and ablation holes similar to the armature surface. Based on the above, it can be concluded that this example achieves ablation reconstruction of the armature and track surface after 100 launches.

[0046] Comparative Example 1

[0047] First, the diameter of the pin sample is machined to 10 mm. After locating the arc initiation point, the arc initiation current is set to 100 A (corresponding to a current density of 1.27 × 10⁻⁶). 6 A / m 2 The disc sample rotates at 1500 rpm to initiate the arc ignition test. Once the disc sample stabilizes at the set speed of 1500 rpm, the electric cylinder moves the pin sample to the arc ignition point to initiate the arc. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. The arc ignition test is repeated until the current in the circuit reaches the set ablation time (1 min in this embodiment). Then, the current loading power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position, completing the arc ignition test. During the arc ignition test, there is a gap between the disc sample and the pin sample. The ablation morphology of the disc sample and the pin sample is as follows. Figure 7 As shown in the image, the surface ablation morphology of the product obtained in Comparative Example 1 shows ablation holes on the surface of the disc sample, but no obvious ablation pits were observed on the 45-shot track, and no melt structure was present on the surface of the pin sample. This indicates that the reconstruction effect on the armature and track in Comparative Example 1 is not significant.

[0048] Comparative Example 2

[0049] First, the diameter of the pin sample is machined to 10 mm. After locating the arc initiation point, the arc initiation current is set to 100 A (corresponding to a current density of 1.27 × 10⁻⁶). 6 A / m 2The disc sample rotates at 1500 rpm to initiate the arc ignition test. Once the disc sample stabilizes at the set speed of 1500 rpm, the electric cylinder moves the pin sample to the arc ignition point to initiate the arc. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. The arc ignition test is repeated until the current in the circuit reaches the set ablation time (3 minutes in this embodiment). Then, the current loading power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position, completing the arc ignition test. During the arc ignition test, there is a gap between the disc sample and the pin sample. The ablation morphology of the disc sample and the pin sample is as follows. Figure 8 As shown in the image, the surface ablation morphology of the product obtained in Comparative Example 2 reveals ablation pits and holes on the disk sample surface. While the ablation degree is more pronounced compared to the 45-shot track, it is insufficient compared to the 100-shot track. Therefore, it is necessary to increase the current density and ablation time, and decrease the disk sample rotation speed, to increase the ablation degree and obtain an ablation reconstruction morphology similar to that of the 100-shot track.

Claims

1. A method for reconstructing an electromagnetic track launch armature and track surface ablation, characterized in that: The reconstruction device used is an improved version of the current-carrying friction tester. It consists of a disc sample, a pin sample, a power supply system, and a high-precision electric cylinder. The pin sample is connected to the pin sample fixture through an insulating layer. The pin sample fixture is connected to the high-precision electric cylinder. During operation, the high-precision electric cylinder pushes the pin sample fixture so that the pin sample moves at a set speed and trajectory. The pin sample is connected to the power system via a wire. After the reconstruction device is assembled, there is a gap between the disc sample and the pin sample. The disc sample is connected to a rotary drive device, and the disc sample can be kept stationary or rotated at a set speed as needed. The reconstruction method includes the following steps: Step 1: Find the starting point of the arc The circuit current loading power supply is turned on, and the power supply provides current. The pin sample is driven by a high-precision electric cylinder to approach the disc sample at a set speed. At this time, the disc sample is stationary. When the pin sample and the disc sample reach the arc-starting distance, an electric arc is generated. At this time, the circuit detects that current is passing through it. The system locates the position, and the electric cylinder drives the pin sample to retract. The arc-starting point is found. Step 2 Arc Initiation Test Set the arc-initiating current, arc-initiating time, and disc sample rotation speed, and begin the arc-initiating test. Once the disc sample stabilizes at the set rotation speed, the electric cylinder moves the pin sample to the arc-initiating point, and the arc-initiating test begins. When the distance between the pin sample and the disc sample increases due to material loss caused by ablation, the arc may disappear. At this time, no current flows through the system detection circuit, and the electric cylinder continues to move the pin sample closer to the disc sample until the arc reappears. Repeat the arc-initiating test until the current in the circuit reaches the set ablation time. Then, the current-loaded power supply is turned off, the disc sample stops rotating, and the electric cylinder moves the pin sample away from the disc sample to the disassembly position, completing this arc-initiating test. The corresponding current density range for the arc-initiating test process is 1.0 × 10⁻⁶. 7 ~3.82×10 8 A / m 2 .

2. The reconstruction method for electromagnetic track launching armature and track surface ablation according to claim 1, characterized in that: Two pin samples were set up.

3. The reconstruction method for electromagnetic track launching armature and track surface ablation according to claim 1, characterized in that: After the current is generated by the power supply system, it flows into the disc sample from one pin and then flows out from the other pin sample. The diameter of the disc sample is 100-300 mm, and the pin sample is a cylinder with a diameter that can be calculated by the required current density, ranging from 1 to 10 mm.

4. The reconstruction method for electromagnetic track launching armature and track surface ablation according to claim 1, characterized in that: The disc sample is made of the same material as the track; the pin sample is made of the same material as the armature.

5. The reconstruction method for electromagnetic track launching armature and track surface ablation according to claim 1, characterized in that: The rotational speed of the control disc sample is 500~3000 rpm, the control current is 50-300A, the diameter of the control pin sample is 1-10mm, and the corresponding current density range during the arc initiation test is 1.0×10⁻⁶. 7 ~3.82×10 8 A / mm 2 .

6. The reconstruction method for electromagnetic track launching armature and track surface ablation according to claim 1, characterized in that: The track material is CuCrZr alloy, and the armature material is 7075 Al alloy.

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