Reconstruction method for surface ablation morphology of emission pivot rail of electromagnetic rail

Abstract

The invention relates to an electromagnetic emission pivot rail surface ablation morphology reconstruction method. Belongs to the technical field of electromagnetic track launching. According to the method, track and armature samples which are actually launched can be obtained under laboratory conditions, destructive disassembly of the electromagnetic launcher is avoided, the cost and period of the method are greatly improved compared with those of a disassembly method, the reconstruction process is simple, and the technological method is easy to operate and control; and carrying out equivalent test and verification on a future electromagnetic emission novel pivot rail friction pair material and a surface treatment material. The reconstruction device is improved, a strategy of finding an arcing point first is adopted, and non-contact ablation reconstruction data accumulation is combined, so that necessary conditions are provided for quickly constructing a scientific and complete reconstruction database of electromagnetic track emission armature and track surface ablation.

Description

Technical Field

[0001] The invention relates to a method for reconstructing the surface ablation morphology of an electromagnetic launch pivot rail, and belongs to the technical field of electromagnetic rail launch. Background Art

[0002] Electromagnetic rail launch technology is a new launch method that uses electromagnetic energy to push objects to achieve ultra-high-speed launch. Its barrel structure consists of two parallel metal rails and a current-carrying armature in the middle. During the launch process, a pulse current flows into one of the rails, passes through the middle armature and flows out from the other rail, forming a strong magnetic field between the parallel metal rails. The current-carrying armature in the middle generates a Lorentz force under the action of the strong magnetic field, thereby pushing the armature carrying the warhead to be ejected at high speed.

[0003] The current-carrying friction process between the armature and the rail is under extreme electromagnetic and thermal coupling conditions. During the launch process, due to the accumulation of friction heat and Joule heat, the armature will soften and the surface will melt, and the armature-rail contact surface will change from "solid-solid" contact, "solid-liquid-solid" contact, to "solid-liquid / arc-solid" contact along the launch direction. During the sliding process between the armature and the rail, the loss of contact will induce the generation of arcs, which will cause erosion damage to the surface of the armature-rail friction pair, seriously affecting the reliability and service life of the launcher.

[0004] At present, common methods for testing the arc ablation of the pivot rail include actual launch tests and equivalent simulation methods. The actual launch test process is complicated, laborious and costly, and is not suitable for studying the ablation properties of materials. China's public patent document CN 117825259 A discloses an equivalent test method for simulating electromagnetic railgun rail ablation, and the method adopted is to use a supersonic plasma generator to generate plasma and spray it onto the surface of the rail sample, thereby obtaining the rail surface ablation morphology. However, the method described requires the generation of a large amount of plasma, the test process cost is high, and only the same workpiece can be tested, and the surface ablation morphology and its correspondence of the pivot rail friction pair cannot be obtained at the same time. China's public patent document CN116202366 A discloses a method for reconstructing the surface of an electromagnetic launch rail. In the patent, the reconstruction of the arc ablation morphology is shown by adjusting parameters such as contact pressure, friction speed, current density, and arcing distance. However, there is a friction process in the friction pair in the early stage of the reconstruction process, and the arc erosion during the arcing process may cause the Al alloy to melt, thereby increasing the arcing distance between the Cu alloy and the Al alloy, and a long arcing process cannot be guaranteed. Summary of the invention

[0005] In view of the deficiencies in the existing technology, the present invention is based on the original patent for track surface reconstruction. During further research, it was found that in the middle and late stages of the electromagnetic track transmitting armature, the armature surface may melt and soften, which may cause a loss of contact between the armature and the track. In order to conduct a better and faster systematic study of this state, the technology recorded in the present invention was developed.

[0006] The present invention can reconstruct the surface ablation morphology of the rear section of the electromagnetic rail launch pivot rail material by adjusting the arc starting test process, and can also be used to test the anti-ablation performance of the pivot rail friction pair after surface treatment (such as coating with an anti-ablation coating).

[0007] The present invention also improves the pin-disc current-carrying friction equipment in view of the deficiencies in the prior art, and newly adds an arc starting point search step to avoid the wear process in the early stage of arc starting. The arc starting process can ensure that the armature material and the track material do not contact and are controlled within a reasonable range, thereby achieving a longer arc starting test process.

[0008] The present invention aims to provide a reasonable method, low process cost, easy control, and can reconstruct the ablation microstructure of the pivot rail friction pair surface at different launch times and different position areas by changing parameters such as current size and arc starting time, so as to provide sufficient research samples for the ablation damage process of the pivot rail friction pair material of electromagnetic rail launch, and guide the development of new high-performance pivot rail friction pair materials and surface treatment processes. At the same time, based on the present invention, the anti-ablation performance of the new pivot rail friction pair material and the materials after different surface treatments can be tested.

[0009] The present invention uses electromagnetic track launching armature material and track material as the reconstructed raw materials, adopts an improved pin-disc current-carrying friction device, sets different current sizes, ablation time and other parameters, and adds functions such as finding the initial arc starting point and controlling the ablation distance to obtain the ablation tissue structure of the track surface under different launch times, and can also test the anti-ablation performance of different armature and track materials.

[0010] The present invention discloses a reconstruction method for electromagnetic rail launch armature and rail surface ablation. The reconstruction device used is improved from a current-carrying friction tester, and comprises 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 tooling through an insulating layer, and the pin sample tooling is connected to the high-precision electric cylinder. When working, the high-precision electric cylinder pushes the pin sample tooling to make the pin sample move at a set speed and trajectory; the pin sample is connected to the power supply system through a wire, and 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 rotation drive device, and the disc sample can be selected to be stationary or rotate at a set rotation speed according to demand; The reconstruction method comprises the following steps: Step 1 Find the arc starting point Turn on the loop current loading power supply, the power supply supplies current, and the pin sample is driven by the high-precision electric cylinder to approach the disk sample at a set speed. At this time, the disk sample is stationary; when the pin sample and the disk sample reach the arc starting distance, an arc is generated. At this time, current is detected in the circuit, the system locates the position, and the electric cylinder drives the pin sample back, and the arc starting point search is completed; Step 2 Arc test Set the arc starting current, arc starting time and disk sample speed, and start the arc starting test. When the disk sample stabilizes to the set speed, the electric cylinder drives the pin sample to the arc starting point, and the arc starting test begins. 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again. Repeat the arc starting test until the current passing through the circuit reaches the set ablation time, the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position. The arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample.

[0011] During the arc starting test, there is a gap between the disk sample and the pin sample. This can maintain the continuous generation of the arc on the one hand, and avoid the ablation morphology reconstructed by the friction contact damage between the pin sample and the disk sample during the test on the other hand, and eliminate all interference caused by friction.

[0012] In practical applications, the ablation morphology of the electromagnetic launch armature and the track surface is reconstructed based on the experimentally obtained microstructure of the disk test and pin sample surface.

[0013] Affected by different current sizes (based on laboratory conditions and safety, using a constant low-voltage power supply and a high-current system), the cross-sectional area of ​​the pin sample, and the state of the gas medium (including air), the arcing distance of each arcing and ablation process may be different. In this regard, the present invention sets an arcing point search step to search for the arcing position before the arcing and ablation test begins. The present invention searches for the arcing position before the arcing and ablation test begins, which can produce a small area of ​​ablation characteristics on the surface of the pin sample, which is beneficial to the generation and stable continuation of the arc during the ablation test, and can quickly move the pin sample to the test point during the test, saving the test process time.

[0014] The arc starting point search process is as follows: the power supply system provides current, the disk sample is stationary, and the high-precision electric cylinder drives the pin sample to approach the disk sample at a speed of 5-20 μm / s through the slide rail. When an arc is generated between the pin sample and the disk sample, current is detected in the electrical circuit system. At this time, the control system locates the arc starting point, and the motor drives the pin sample back to complete the arc starting point search.

[0015] After completing the arc starting position search, set the arc starting current, arc starting time and disk sample speed, and the motor drives the pin sample to the arc starting point, and the arc starting test begins. When the distance between the pin sample and the disk sample increases due to ablation, the loop current in the system disappears, and the motor continues to drive the pin sample to approach the disk sample at a set speed (such as 10 μm / s) until the current is detected in the loop again and the arc continues to be generated. The above steps are repeated until the set arc starting time is reached, the loop power is disconnected, the motor drives the pin sample back, the disk sample stops, and the arc starting test is completed.

[0016] The pin-disk friction device used in the present invention can greatly reduce the space and venue used for the experiment. In addition, the present invention uses corresponding experimental parameters (order of magnitude difference) that are much smaller than the current, speed and other condition parameters used in the existing electromagnetic rail launch technology (especially electromagnetic guns), and can construct the ablation state of the pivot rail friction pair under different launch times through the accumulation of ablation time, and obtain the ablation sample of the pivot rail friction pair surface with ablation characteristic correspondence.

[0017] The present invention uses a pin-on-disc 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 ablation degree of the disk sample and the pin sample can produce a superimposed effect due to the use of a rotary ablation method. By controlling the ablation current and ablation time, reconstruction of the morphology similar to that of the actual armature and track surface under different launch times can be achieved.

[0018] The present invention provides a reconstruction method for electromagnetic rail launch armature and rail surface ablation, wherein two pin samples are set; the ablation current in the present invention is supplied by a constant voltage power supply system, and after the current is generated by the power supply system, it flows from one pin to the disc sample and then flows out from another pin sample ( Figure 1 ), wherein the disc sample has a diameter of 100-300 mm, and the pin sample is a cylinder, the diameter of which can be calculated by the required current density, and the diameter is between 1-10 mm. In the present invention, the material of the disc sample is the material used for the track; the pin sample is the material used for the armature.

[0019] The present invention discloses a reconstruction method for electromagnetic rail launch armature and rail surface ablation, wherein the device is improved from a current-carrying friction tester and comprises a disc sample, a pin sample, an external power supply, and a high-precision electric cylinder ( Figure 1 ). By adding the arc starting point search step, the problem of arc starting distance change caused by different current size, sample size and air medium is solved. And according to the detection of current in the circuit, the arc starting distance can be maintained during the ablation test to achieve a long-term stable arc starting test.

[0020] The invention discloses a reconstruction method of electromagnetic rail launch armature and rail surface ablation, which adopts rail material as disc sample material, adopts armature material as pin sample material, controls the rotation speed of disc sample to be 0-3000rpm, preferably 500-3000rpm, controls the current size to be 50-300A, controls the pin sample diameter to be 1-10mm, and corresponds to the current density range of 6.37×10 4 ~3.82×10 8 A / mm 2 , preferably 1.0×10 7 ~3.82×10 8 A / mm 2 In the present invention, such a large current density is used to make it easier to stimulate the arc and maintain stability. If it is too low, it will lead to problems such as arc starting difficulty and unclear reconstruction effect. If it is too high, it will cause the pin sample to melt too quickly due to heat, and the distance between the pin sample and the disc sample will increase, making it impossible to maintain the arc for a long time.

[0021] The present invention provides a reconstruction method for electromagnetic track transmitting armature and track surface ablation. Preferably, the track material is CuCrZr alloy, and the armature material is 7075Al alloy.

[0022] For the study of the ablation of the surface of the pivot-rail friction pair, the current method basically adopts the disassembly analysis of the orbit after launch, and due to the high exit rate of the launch armature, the armature recovery efficiency is extremely low. The present invention forms a method that can obtain orbit and armature samples after actual launch under laboratory conditions, avoiding destructive disassembly of the electromagnetic launcher. Its cost and cycle are greatly improved compared with the disassembly method, the reconstruction process is simple, and the process method is easy to operate and control. In addition, according to the present invention, the equivalent test and verification of the new pivot-rail friction pair materials and surface treatment materials for future electromagnetic launches can be carried out. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 is a schematic diagram of an arc ablation device; Attached Figure 2 This is the ablation morphology of the orbital surface after 45 rounds of firing; Attached Figure 3 This is the ablation morphology of the orbital surface after 100 rounds of firing; Attached Figure 4 This is the surface ablation morphology of the armature launched and recovered for the 45th time in the launch orbit; Attached Figure 5 This is the surface reconstruction image obtained in Example 1; Attached Figure 6 This is the surface reconstruction image obtained in Example 2; Attached Figure 7This is the surface reconstruction image obtained in Comparative Example 1; Attached Figure 8 This is the surface reconstruction image obtained in Comparative Example 2. DETAILED DESCRIPTION

[0024] 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 material used for the track (specifically, CuCrZr alloy); the pin sample is the material used for the armature (specifically, 7075Al alloy); and the diameter of the disc sample is 180 mm.

[0025] Step 1 Find the arc starting point Turn on the loop current loading power supply, the power supply supplies current, and the pin sample is driven by the high-precision electric cylinder to approach the disk sample at a set speed. At this time, the disk sample is stationary; when the pin sample and the disk sample reach the arc starting distance, an arc is generated. At this time, current is detected in the circuit, the system locates the position, and the electric cylinder drives the pin sample back, and the arc starting point search is completed; Step 2 Arc test Set the arc starting current, arc starting time and disk sample speed, and start the arc starting test. When the disk sample stabilizes to the set speed, the electric cylinder drives the pin sample to the arc starting point, and the arc starting test begins. 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again. Repeat the arc starting test until the current passing through the circuit reaches the set ablation time, the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position. The arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample.

[0026] Example 1 First, the diameter of the pin sample was processed to 10 mm. After finding the arc starting point, the arc starting current was set to 100 A (corresponding to a current density of 1.27×10 6 A / m 2), the disk sample rotates at a speed of 1500 rpm, and the arc starting test is started. When the disk sample stabilizes to the set speed of 1500 rpm, the electric cylinder drives the pin sample to the arc starting point and starts arcing; 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again; the arc starting test is repeated until the current passing through the circuit reaches the set ablation time (2 min in this embodiment), the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position. The arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample. The ablation morphology of the disk sample and the pin sample is as shown in the figure. Figure 5 As shown. From the surface ablation morphology of the product obtained in Example 1, it can be seen that some ablation pits and ablation holes appear on the track surface, which are similar to the ablation pits in the ablation morphology of the track surface with 45 shots. Combining the two, it can be seen that: their ablation characteristics are similar, the occupied areas are basically the same, and the surface of the pin sample has a melt structure and ablation holes similar to those on the armature surface. Combining the above parts, it can be concluded that the ablation reconstruction of the armature and track surface is achieved in this embodiment.

[0027] Accumulating pictures of different pin sample diameters, different currents, different speeds and different times provides necessary conditions for subsequent reconstruction. At the same time, the present invention can also more scientifically restore the influence of the on-site atmosphere on the electromagnetic track and the armature.

[0028] Example 2 First, the diameter of the pin sample was processed to 2 mm. After finding the arc starting point, the arc starting current was set to 300 A (corresponding to a current density of 9.55×10 7 A / m 2 ), the disk sample speed is 500 rpm, and the arc starting test is started. When the disk sample stabilizes to the set speed of 500 rpm, the electric cylinder drives the pin sample to the arc starting point and starts arcing; 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again; the arc starting test is repeated until the current passing through the circuit reaches the set ablation time (5 minutes in this embodiment), the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position, and the arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample, and its ablation morphology is as shown in Figure 6As shown. From the surface ablation morphology of the product obtained in Example 2, it can be seen that the track surface is almost covered with ablation pits and ablation holes, which are similar to the ablation pits in the ablation morphology of the track surface with 100 shots. Combining the two, it can be seen that their ablation characteristics are similar, the occupied area is basically the same, and the surface of the pin sample has a melt structure and ablation holes similar to those on the armature surface. Combining the above parts, it can be concluded that the ablation reconstruction of the armature and track surface is achieved under this embodiment for 100 shots.

[0029] Comparative Example 1 First, the diameter of the pin sample is processed to 10 mm. After finding the arc starting point, the arc starting current is set to 100 A (corresponding to a current density of 1.27×106A / m2), the disk sample rotation speed is 1500 rpm, and the arc starting test is started. When the disk sample stabilizes to the set rotation speed of 1500 rpm, the electric cylinder drives the pin sample to the arc starting point and starts arcing. 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again. Repeat the arc starting test until the current passes through the circuit for a long time to reach the set ablation time (1 min in this embodiment), then the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position. The arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample. The ablation morphology of the disk sample and the pin sample is as follows: Figure 7 As shown. From the surface ablation morphology of the product obtained in comparative example 1, it can be seen that ablation holes appear on the surface of the disc sample, but there is no obvious ablation pit morphology on the 45-round track, and there is no melt structure on the surface of the pin sample. This shows that the reconstruction effect of the armature and the track in comparative example 1 is not obvious.

[0030] Comparative Example 2 First, the diameter of the pin sample is processed to 10 mm. After finding the arc starting point, the arc starting current is set to 100 A (corresponding to a current density of 1.27×106A / m2), the disk sample rotation speed is 1500 rpm, and the arc starting test is started. When the disk sample stabilizes to the set rotation speed of 1500 rpm, the electric cylinder drives the pin sample to the arc starting point and starts arcing. 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again. Repeat the arc starting test until the current passes through the circuit for a long time to reach the set ablation time (3 min in this embodiment), then the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position. The arc starting test is completed. During the arc starting test, there is a distance between the disk sample and the pin sample. The ablation morphology of the disk sample and the pin sample is as follows: Figure 8As shown. From the surface ablation morphology of the product obtained in Comparative Example 2, it can be seen that ablation pits and ablation holes appear on the surface of the disc sample, but the ablation degree is more obvious than that of the 45-round track, but compared with the 100-round track, the ablation degree is insufficient. Therefore, it is necessary to increase the current density and ablation time, reduce the rotation speed of the disc sample, and increase the ablation degree, in order to obtain an ablation reconstruction morphology similar to that of the 100-round track.

Claims

1. A method for reconstructing electromagnetic rail launch armature and rail surface ablation, characterized in that: The reconstruction device used is improved from a current-carrying friction tester, and includes 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 through an insulating layer, and the pin sample fixture is connected to a high-precision electric cylinder. When working, the high-precision electric cylinder pushes the pin sample fixture to make the pin sample move at a set speed and trajectory. The pin sample is connected to the power supply system through a wire. After the reconstruction device is assembled, there is a gap between the disk sample and the pin sample. The disk sample is connected to a rotation drive device. The disk sample can be selected to be stationary or rotate at a set rotation speed according to needs. The reconstruction method comprises the following steps: Step 1 Find the arc starting point Turn on the loop current loading power supply, the power supply supplies current, and the pin sample is driven by the high-precision electric cylinder to approach the disk sample at a set speed. At this time, the disk sample is stationary; when the pin sample and the disk sample reach the arc starting distance, an arc is generated. At this time, current is detected in the circuit, the system locates the position, and the electric cylinder drives the pin sample back, and the arc starting point search is completed; Step 2 Arc test Set the arc starting current, arc starting time and disk sample speed, and start the arc starting test. When the disk sample stabilizes to the set speed, the electric cylinder drives the pin sample to the arc starting point, and the arc starting test begins. 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, the system detects that there is no current passing through the circuit, and the electric cylinder continues to drive the pin sample close to the disk sample until the arc appears again. Repeat the arc starting test until the current passing through the circuit reaches the set ablation time, the current loading power supply is turned off, the disk sample stops rotating, and the electric cylinder drives the pin sample away from the disk sample to the disassembly position, and the arc starting test is completed.

2. A method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: Two pin specimens are provided.

3. A method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: After the current is generated by the power supply system, it flows from a pin into the disk sample and then flows out from another pin sample. The disk sample has a diameter of 100-300 mm. The pin sample is a cylinder whose diameter can be calculated based on the required current density and is between 1-10 mm.

4. A method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: The material of the disc sample is the material used for the track; the material of the pin sample is the material used for the armature.

5. The method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: The speed of the control panel sample is 0-3000 rpm, the control current is 50-300 A, the diameter of the control pin sample is 1-10 mm, and the current density range of the corresponding arc starting test process is 6.37×10 4 -3.82×10 8 A / mm 2 .

6. A method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: The rotation speed of the control panel sample is 500~3000rpm, the control current is 50-300A, the diameter of the control pin sample is 1-10mm, and the corresponding current density range of the arc starting test process is 1.0×10 7 ~3.82×10 8 A / mm 2 .

7. A method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: The current density range of the arc starting test process is 1.0×10 7 ~3.82×10 8 A / m 2 .

8. The method for reconstructing electromagnetic rail launch armature and rail surface ablation according to claim 1, characterized in that: The rail material is CuCrZr alloy, and the armature material is 7075 Al alloy.

Images