An electromagnetic railgun armature capable of reducing aluminum adhesion and a surface modification method

Abstract

The invention provides an electromagnetic rail gun armature capable of reducing aluminum adhesion and a surface modification method, belonging to the field of electromagnetic rail guns. The armature surface of the invention has a modified film, the modified film has positive mixing heat with the copper alloy material of the electromagnetic rail, has conductive properties, and has a higher softening temperature and surface hardness than the Al alloy matrix material of the armature itself. The modified film is a pure tungsten film, a pure silver film, a titanium alloy film, a TiC alloy film, a tungsten stainless steel film or / and a chromium stainless steel film, the modified film thickness is 800nm-8μm, and the modified film presents a columnar crystal structure. The modified film is prepared on the armature surface by magnetron sputtering. The power of magnetron sputtering is 30W-200W, the temperature of the armature surface is 298K-423K, the sputtering time is 30min-300min, and the protective gas is argon. The invention can effectively reduce the aluminum alloy adhesion problem caused by melt deposition during the electromagnetic gun armature launch process by preparing the modified film on the armature surface.

Description

Technical Field

[0001] The invention belongs to the field of electromagnetic rails, and more specifically, relates to an electromagnetic rail gun armature capable of reducing aluminum adhesion and a surface modification method. Background Art

[0002] The research and development of new concept weapons is an important measure to establish the country's military and technological advantages. As a new concept of high-kinetic energy lethal weapon, the electromagnetic rail launcher can surpass the limits of traditional chemical energy weapons. Unlike traditional artillery that relies on gas expansion to propel the projectile, the electromagnetic rail launcher drives the projectile through the Lorentz force in the strong electromagnetic field generated by the instantaneous large current, and directly uses electromagnetic energy to accelerate the projectile to the limit for a short time. The electromagnetic rail launcher has the advantages of fast projectile flight speed (up to several km / s), long range (up to hundreds of km), strong lethality, and high cost-effectiveness. It also has asymmetric combat advantages in the fields of long-range firepower strikes, short-range air defense and anti-missile, and has attracted widespread attention from military powers around the world. The development of new electromagnetic rail launch technology is of great strategic significance to my country's national defense security.

[0003] During the operation of the electromagnetic launch device, the track is in a harsh working environment with high current, instantaneous high temperature and strong magnetic field. The sliding electrical contact condition between the armature and the track is very poor. Complex electrical, magnetic, thermal and force effects and strong side impact forces will occur between the armature and track interfaces, causing damage to the track material in the form of wear, planing and ablation, seriously affecting the service performance and life of the electromagnetic launch equipment.

[0004] At present, the electromagnetic track material mainly uses high-strength and high-conductivity copper alloys (such as nano-alumina dispersed copper), and the armature material is basically selected as lightweight and high-strength 7-series aluminum alloy. Due to the instantaneous large current and Joule heat, the aluminum alloy armature material with a lower melting point will melt first, forming a liquefied layer on the sliding surface, and finally deposited on the surface of the copper alloy track. The melting of the armature surface and the formation of the Al alloy adhesion layer will have a significant negative impact on the contact state of the armature and rail: first, the surface melting will cause the armature mass loss, resulting in the separation of the armature and rail contact and the formation of an arc; second, the Al alloy adhesion layer containing brittle intermetallic compounds will cause the surface state of the track material to change (such as increased roughness and reduced conductivity), resulting in track groove corrosion and wear.

[0005] In recent years, domestic and foreign research has mainly focused on the development of new Cu alloy track materials or surface modification of conventional Cu alloy tracks to improve the track surface wear resistance and ablation resistance. However, these material systems are still mainly Cu-based or Ni-based alloys, and the problem of armature material (Al alloy) melting and deposition on the guide rail has not been fundamentally solved, which has become one of the bottleneck problems limiting the service life of electromagnetic tracks.

[0006] Therefore, in order to solve the problem of Al alloy deposition and damage on the surface of electromagnetic rails, a new technology needs to be developed. Summary of the invention

[0007] In view of the defects of the prior art, the purpose of the present invention is to provide an electromagnetic rail gun armature and a surface modification method that can reduce aluminum adhesion, construct a coating material that is immiscible with Cu on the surface of the Al alloy armature, and regulate the armature interface energy and the electrical and thermal conductivity and anti-ablation properties, so as to effectively reduce the aluminum alloy adhesion problem caused by melt deposition during the electromagnetic gun armature launch process, thereby meeting the service requirements of the electromagnetic rail launch device.

[0008] To achieve the above-mentioned purpose, the present invention provides an electromagnetic railgun armature capable of reducing aluminum adhesion, wherein the surface of the electromagnetic railgun armature has a modified film, the modified film has positive mixing heat with the copper alloy material of the electromagnetic rail, has conductive properties, and has a higher softening temperature and surface hardness than the Al alloy matrix material of the armature itself, wherein the modified film is a pure tungsten film, a pure silver film, a titanium alloy film, a TiC alloy film, a tungsten stainless steel film, and a chromium stainless steel film.

[0009] Furthermore, the thickness of the modified film is 800 nm to 8 μm, and the modified film has a columnar crystal structure.

[0010] Furthermore, the components included in the pure tungsten film and the mass percentages of each component are: W≥95%, and the remainder is inevitable impurities; the components included in the pure silver film and the mass percentages of each component are: Ag≥95%, and the remainder is inevitable impurities.

[0011] Furthermore, the titanium alloy film includes components and the mass percentages of the components are: Ti≥70%, C≤30%, the sum of the mass percentages of Ti and C is 100%, and the C content is greater than zero.

[0012] Furthermore, the TiC alloy film includes components and the mass percentage of each component is: TiC ≥ 70%, W ≤ 30%, the sum of the mass percentage of TiC and the mass percentage of W is 100%, and the content of W is greater than 0.

[0013] Furthermore, the components of the tungsten stainless steel film and the mass percentages of the components are as follows:

[0014] W 40%~60%, Cr 6%~10%, Ni 5%~10%, Mn 0.5%~2%, Si 0.1%~1%, Mo0.5%~2%, C 0.01~0.02%, and the balance is Fe.

[0015] Furthermore, the components included in the chromium stainless steel film and the mass percentages of the components are respectively:

[0016] Cr 16%~20%, Ni 5%~18%, Mn 1%~2%, Si 0.1%~1%, Mo 0.01%~2%, C0.01~0.05%, P 0~0.05%, S 0~0.009%, and the balance is Fe.

[0017] According to a second aspect of the present invention, there is also provided a method for preparing the electromagnetic railgun armature with reduced aluminum adhesion as described above, comprising the following steps:

[0018] S1: Powder metallurgy or sintering of materials with required components, and then processing them into target materials;

[0019] S2: Smooth the surface of the armature and clean and dry it;

[0020] In general, the above technical solution conceived by the present invention has the following advantages compared with the prior art:

[0021] Beneficial effects:

[0022] 1. The present invention contains a conductive armature surface modification film that is non-miscible with copper alloy, i.e., has a positive mixing heat with Cu. It has a dense structure, good arc erosion resistance, good friction and wear resistance, and has a positive mixing heat with alumina dispersed copper. It has a higher softening temperature and surface hardness than 7075Al alloy (softening hardness>400°C, surface hardness>135HB), and is expected to improve the aluminum alloy deposition damage problem on the surface of the electromagnetic gun track. Compared with 7075Al alloy, the film effectively reduces the amount of copper alloy adhesion by 3 to 16 times.

[0023] 2. The present invention adopts a single target material magnetron sputtering method to prepare a conductive film having positive mixing heat with a copper alloy, which can flexibly control the thickness of the film, has high repeatability and can be industrialized, has strong process operability, and has low manufacturing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is a schematic diagram of the cross-sectional profile of a copper alloy sample after arc ablation experiment in an embodiment of the present invention;

[0025] Figure 2 Schematic diagram of the cross-sectional profile of the sample after arc ablation experiment of the tungsten film sample and the 7075Al alloy substrate in the embodiment of the present invention;

[0026] Figure 3 is the adhesion amount of different material films and 7075Al substrate on copper alloy after the friction and wear test in the embodiment of the present invention;

[0027] Figure 4 is the friction coefficient of the different material films against the 7075Al substrate and the copper alloy in the embodiment of the present invention;

[0028] Figure 5 is a three-dimensional white light interference diagram of the copper alloy surface after the Ti-C film and the copper alloy are rubbed against each other in an embodiment of the present invention;

[0029] Figure 6 is a three-dimensional white light interference diagram of the copper alloy surface after the W film and the copper alloy are rubbed against each other in an embodiment of the present invention;

[0030] Figure 7 is a three-dimensional white light interference diagram of the copper alloy surface after the 316L film and the copper alloy are rubbed against each other in an embodiment of the present invention;

[0031] Figure 8 is a three-dimensional white light interference diagram of the copper alloy surface after the 7075 alloy substrate and the copper alloy are rubbed against each other in an embodiment of the present invention;

[0032] Fig. 9 is a SEM image of the copper alloy surface after the W film and the copper alloy are rubbed against each other in an embodiment of the present invention;

[0033] Fig.10 It is a SEM image of the copper alloy surface after rubbing the 7075Al alloy matrix against the copper alloy in the embodiment of the present invention. DETAILED DESCRIPTION

[0034] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0035] In view of the problems of the prior art, the present invention takes a different approach and uses magnetron sputtering technology to modify the surface of the armature material, constructs a Cu-immiscible coating on the surface of the Al alloy armature, and regulates its interfacial energy and electrical and thermal conductivity and ablation resistance to meet the service requirements of the electromagnetic rail launcher. Specifically, the present invention provides an armature surface modification method for reducing aluminum adhesion of the electromagnetic rail, and its purpose is to provide an armature surface modification film based on the selection of a conductive armature surface modification film with positive mixing heat with the copper alloy, so as to effectively reduce the aluminum alloy adhesion problem caused by melt deposition during the electromagnetic gun armature launch process.

[0036] The electromagnetic rail gun armature surface capable of reducing aluminum adhesion of the present invention has a modified film, the modified film and the copper alloy material of the electromagnetic rail have positive mixing heat, have conductive properties, and have higher softening temperature and surface hardness than the Al alloy matrix material of the armature itself, and the modified film is a pure tungsten film, a pure silver film, a titanium alloy film, a TiC alloy film, a tungsten stainless steel film, and a chromium stainless steel film. The modified film thickness is 800nm ​​to 8μm, and such a film thickness can bring about the effect of strengthening the adhesion of the film to the matrix, reducing the accumulation of internal stress, and effectively improving the friction and wear performance. The modified film has a columnar crystal structure, and such a film structure brings about the effect of dense grain boundaries, few internal defects, and good mechanical properties.

[0037] Specifically, the components included in the pure tungsten film and the mass percentage of each component are: W ≥ 95%, and the remainder is inevitable impurities. The components included in the pure silver film and the mass percentage of each component are: Ag ≥ 95%, and the remainder is inevitable impurities. Inevitable impurities refer to impurities added during powder metallurgy such as powder making, mixing, forming, roasting and post-processing, or a very small amount of carbon elements fixedly added using carbon conductive glue during magnetron sputtering. The components included in the titanium alloy film and the mass percentage of each component are: Ti ≥ 70%, C ≤ 30%, and the sum of the mass percentages of Ti and C is 100%, and the C content is greater than 0. The components included in the TiC alloy film and the mass percentage of each component are: TiC ≥ 70%, W ≤ 30%, the sum of the mass percentage of TiC and the mass percentage of W is 100%, and the content of W is greater than 0. The components and mass percentages of the tungsten stainless steel film are: W 40%-60%, Cr 6%-10%, Ni 5%-10%, Mn 0.5%-2%, Si 0.1%-1%, Mo 0.5%-2%, C 0.01-0.02%, and the balance is Fe. The components and mass percentages of the chromium stainless steel film are: Cr 16%-20%, Ni 5%-18%, Mn 1%-2%, Si 0.1%-1%, Mo 0.01%-2%, C0.01-0.05%, P 0-0.05%, S 0-0.009%, and the balance is Fe. That is, the components of the modified film for preparing the armature surface are mainly limited to the above types.

[0038] The present invention adopts magnetron sputtering to prepare the modified film on the armature surface. It includes the following steps:

[0039] S1: Powder metallurgy or sintering of materials with required components, and then processing them into target materials;

[0040] S2: Smooth the surface of the armature and clean and dry it;

[0041] S3: magnetron sputtering is performed. The parameters of magnetron sputtering are: the background vacuum value is less than or equal to 5×10 -4 Pa, the power is 30W~200W, the target substrate distance is 40mm~100mm, the protective gas pressure is 0.2Pa~6.0Pa, the temperature of the armature surface is 298K~423K, the sputtering time is 30min~300min, and the protective gas is argon.

[0042] In order to better illustrate the method and the armature surface modification film of the present invention, they are further described in detail below in conjunction with specific embodiments.

[0043] Example 1

[0044] The main component of the armature surface modified tungsten alloy film that is immiscible with copper alloy and conductive in this embodiment is W, and the mass percentage (wt.%) of the elements are respectively:

[0045] W 99.999

[0046] Others are unavoidable residual impurities

[0047] Its preparation method is:

[0048] S1: Prepare the target material, use powder metallurgy to make a pure tungsten alloy target with a purity of 99.99wt%, then use a rolling machine to process it to a diameter of 60*3mm, and then ultrasonically clean and dry it;

[0049] S2: Processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying. Specifically, the substrate is cleaned with acetone, alcohol and deionized water in sequence, and finally blown dry for use.

[0050] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, fill the sputtering chamber with argon gas to stabilize the argon pressure at 1.0Pa, the sputtering power is 100W, and the target-substrate distance is 60mm. Specifically, first, close the target baffle, pre-sputter for 10min to remove the oxide film on the target surface, and after the sputtering glow is stable, open the target baffle, keep the argon pressure, sputtering power, and target-substrate distance stable, and sputter for 90min. During this process, the circulating water system is used to ensure that the substrate temperature is 363K, that is, the W film is obtained.

[0051] The pure tungsten alloy film obtained in this embodiment has a thickness of 3.9 μm and a columnar crystal structure. The atomic percentage content of the components is: W 99.99 wt.%, and the rest is the balance.

[0052] Example 2

[0053] The main components of the armature surface modified tungsten stainless steel film that is immiscible with copper alloy and conductive in this embodiment are W, Cr, Ni, Mn, Si, Mo, C, and Fe, and the mass percentage (wt.%) of the elements are respectively:

[0054] W 50.00

[0055] Cr 8.50

[0056] Ni 7.00

[0057] Mn 1.00

[0058] Si 0.50

[0059] Mo 1.00

[0060] C 0.015

[0061] Fe Residue

[0062] Its preparation method is:

[0063] S1: Prepare the target material, use powder metallurgy to make the alloy according to the raw material ratio into a tungsten alloy target, then use a rolling machine to process it to a diameter of 60*3mm, and then ultrasonically clean and dry it.

[0064] S2: Processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying. Specifically, the substrate is cleaned with acetone, alcohol and deionized water in sequence, and finally blown dry for use.

[0065] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, argon is filled into the sputtering chamber to stabilize the argon pressure at 1.0Pa, the sputtering power is 100W, and the target-substrate distance is 60mm. First, the target baffle is closed, and pre-sputtering is performed for 10 minutes to remove possible oxide film on the target surface. After the sputtering glow is stable, the target baffle is opened, and the argon pressure, sputtering power, and target-substrate distance are kept stable for 90 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363K, that is, a tungsten alloy film is obtained.

[0066] The tungsten stainless steel alloy film obtained in this embodiment has a thickness of 3.9 μm and a columnar crystal structure. The mass percentage content of the components is: W 50.00wt%, Cr 8.50wt%, Ni 7.00wt%, Mn 1.00wt%, Si 0.50wt%, Mo1.00wt%, C 0.015wt%, and Fe balance.

[0067] Example 3

[0068] This embodiment is the same as the embodiment 2, except that the composition of the tungsten stainless steel film is different. The main components of this embodiment are W, Cr, Ni, Mn, Si, Mo, C, and Fe, and the mass percentage (wt.%) of the elements are:

[0069] W 40.00

[0070] Cr 10

[0071] Ni 5

[0072] Mn2

[0073] Si 0.1

[0074] Mo 2

[0075] C 0.01

[0076] Fe Residue

[0077] The preparation method is the same as that of Example 2, except that in step S3, the background vacuum value is 4×10 -4 Pa, the power is 200 W, the target substrate distance is 40 mm, the protective gas pressure is 0.2 Pa, the temperature of the armature surface is 298 K, the sputtering time is 30 min, and the protective gas is argon.

[0078] The thickness of the tungsten-stainless steel alloy film obtained in this embodiment is 8 μm, and it has a columnar crystal structure.

[0079] Example 4

[0080] This embodiment is the same as the embodiment 2, except that the composition of the tungsten stainless steel film is different. The main components of this embodiment are W, Cr, Ni, Mn, Si, Mo, C, and Fe, and the mass percentage (wt.%) of the elements are:

[0081] W 60

[0082] Cr 6

[0083] Ni 10

[0084] Mn 0.5

[0085] Si 1

[0086] Mo 0.5

[0087] C 0.05

[0088] Fe Residue

[0089] The preparation method is the same as that of Example 2, except that in step S3, the background vacuum value is 5×10 -4Pa, the power is 30 W, the target substrate distance is 100 mm, the protective gas pressure is 6.0 Pa, the temperature of the armature surface is 423 K, the sputtering time is 300 min, and the protective gas is argon.

[0090] The thickness of the tungsten-stainless steel alloy film obtained in this embodiment is 800 nm, and it has a columnar crystal structure.

[0091] Example 5

[0092] The chromium stainless steel film on the surface of the armature that is immiscible with the copper alloy and conductive in this embodiment mainly comprises Fe, Cr, Ni, Mn, Si, Mo, and C, and the mass percentage (wt.%) of the elements are respectively:

[0093] Cr 17.00

[0094] Ni 14.00

[0095] Mn 2.00

[0096] Si 1.00

[0097] Mo 2.00

[0098] C 0.03

[0099] P 0

[0100] S 0

[0101] Fe Residue

[0102] Its preparation method is:

[0103] S1: Prepare the target material, use powder metallurgy to make the alloy according to the raw material ratio into 316L alloy target, then use rolling machine to process it to a diameter of 60*3mm, and then ultrasonically clean and dry it;

[0104] S2: processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying;

[0105] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, argon is filled into the sputtering chamber to stabilize the argon pressure at 1.0Pa, the sputtering power is 80W, and the target-substrate distance is 70mm. First, the target baffle is closed, and pre-sputtering is performed for 10 minutes to remove possible oxide film on the target surface. After the sputtering glow is stable, the target baffle is opened, and the argon pressure, sputtering power and target-substrate distance are kept stable for 80 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363K, that is, the 316L film obtained has a film thickness of 3.5μm, and it is tested to have a columnar crystal structure.

[0106] Example 6

[0107] The main components of the armature surface modified chromium stainless steel alloy film that is immiscible with copper alloy and electrically conductive are Fe, Cr, Ni, Mn, Si, Mo, C, P, and S, and the mass percentage (wt.%) of the elements are respectively:

[0108] Cr 18.25

[0109] Ni 8.00

[0110] Mn 1.25

[0111] Si 0.50

[0112] C 0.02

[0113] P 0.03

[0114] S 0.005

[0115] Fe Residue

[0116] Its preparation method is:

[0117] S1: Prepare the target material, use powder metallurgy to make the alloy according to the raw material ratio into 304L alloy target, then use rolling machine to process it to a diameter of 60*3mm, and then ultrasonically clean and dry it;

[0118] S2: Processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying; the drying is specifically washing with acetone, alcohol and deionized water in sequence, and finally blowing dry for standby use.

[0119] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, argon is filled into the sputtering chamber to stabilize the argon pressure at 0.2Pa, the sputtering power is 100W, and the target-substrate distance is 60mm. First, the target baffle is closed, and pre-sputtering is performed for 10 minutes to remove possible oxide film on the target surface. After the sputtering glow is stable, the target baffle is opened to maintain the stability of argon pressure, sputtering power and target-substrate distance, and sputtering is performed for 100 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363K, that is, the obtained 304L film.

[0120] The 304L film obtained in this example has a thickness of 4.9 μm and has a columnar crystal structure.

[0121] Example 7

[0122] The main components of the armature surface modified chromium stainless steel alloy film that is immiscible with copper alloy and electrically conductive are Fe, Cr, Ni, Mn, Si, Mo, C, P, and S, and the mass percentage (wt.%) of the elements are respectively:

[0123] Cr 16

[0124] Ni 5

[0125] Mn2

[0126] Si 0.1

[0127] Mo 0.01

[0128] C 0.05

[0129] P 0.05

[0130] S 0.009

[0131] Fe Residue

[0132] The preparation method is the same as that of Example 5, except that in step S3, argon is filled into the sputtering chamber to stabilize the argon pressure at 5.0 Pa, the sputtering power is 60 W, the target substrate distance is 50 mm, the target baffle is first closed, and pre-sputtering is performed for 10 minutes to remove the oxide film that may exist on the target surface. After the sputtering glow is stable, the target baffle is opened, the argon pressure, sputtering power, and target substrate distance are kept stable, and sputtering is performed for 280 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363 K, that is, the 304L film is obtained. The 304L film obtained in this embodiment has a thickness of 6.8 μm and has a columnar crystal structure.

[0133] Example 8

[0134] This embodiment is the same as embodiment 7, except that the main components of the chromium stainless steel alloy film and the mass percentage of each component are:

[0135] Cr 20

[0136] Ni 18

[0137] Mn 1

[0138] Si 0.8

[0139] Mo 0.9

[0140] C 0.02

[0141] P 0.01

[0142] Fe Residue

[0143] The preparation method of this embodiment is the same as that of embodiment 7, except that in step S3, argon is filled into the sputtering chamber to stabilize the argon pressure at 3.0 Pa, the sputtering power is 190 W, the target substrate distance is 90 mm, the target baffle is first closed, and pre-sputtering is performed for 10 minutes to remove the oxide film that may exist on the target surface. After the sputtering glow is stable, the target baffle is opened, the argon pressure, sputtering power, and target substrate distance are kept stable, and sputtering is performed for 40 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 298 K. The thickness of the modified film obtained in this embodiment is 1.2 μm, and it has a columnar crystal structure.

[0144] Example 9

[0145] The armature surface modified titanium alloy film of the present embodiment that is immiscible with copper alloy and electrically conductive is mainly composed of Ti and C, and the mass percentage (wt.%) of the elements are respectively:

[0146] Ti 70.00

[0147] C 30.00

[0148] Its preparation method is:

[0149] S1: Prepare the target material, sinter the powder according to the raw material ratio into a titanium alloy target with a diameter of 60*3mm, ultrasonically clean and dry it, and bind a copper target of the same size behind the titanium alloy target;

[0150] S2: Processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying; the drying is specifically washing with acetone, alcohol and deionized water in sequence, and finally blowing dry for standby use.

[0151] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, argon is filled into the sputtering chamber to stabilize the argon pressure at 1.0 Pa, the sputtering power is 100 W, and the target-substrate distance is 60 mm. First, the target baffle is closed, and pre-sputtering is performed for 10 minutes to remove possible oxide film on the target surface. After the sputtering glow is stable, the target baffle is opened, and the argon pressure, sputtering power and target-substrate distance are kept stable for 90 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363 K, and a titanium alloy film is obtained.

[0152] The titanium alloy film obtained in this embodiment has a thickness of 3.9 μm and a columnar crystal structure. The atomic percentage contents of the components are: Ti 70.00 wt %, C 30.00 wt %.

[0153] In the composition of the titanium alloy film, the content of Ti and the content of C can be regulated within respective ranges, wherein the content of Ti is not higher than 70% by mass, and the content of C is not higher than 30% by mass.

[0154] Example 10

[0155] The armature surface modified TiC-doped alloy film of the present embodiment that is immiscible with copper alloy and conductive is mainly composed of TiC and W, and the mass percentage (wt.%) of the elements are respectively:

[0156] TiC 70.00

[0157] W 30.00

[0158] Its preparation method is:

[0159] S1: Prepare the target material, sinter the powder according to the raw material ratio into a TiC-doped alloy target with a diameter of 60*3mm, clean and dry it by ultrasonic, and bind a copper target of the same size behind the TiC-doped alloy target;

[0160] S2: Processing the substrate, selecting 7075Al alloy as the substrate material, flattening the substrate surface to make it smooth, and then cleaning and drying. The drying process is specifically to clean with acetone, alcohol and deionized water in sequence, and finally blow dry for standby use.

[0161] S3: Perform magnetron sputtering. First, evacuate the vacuum to a value of 5×10 -4 Pa, argon is filled into the sputtering chamber to stabilize the argon pressure at 1.0 Pa, the sputtering power is 40 W, and the target-substrate distance is 40 mm. First, the target baffle is closed, and pre-sputtering is performed for 10 minutes to remove possible oxide film on the target surface. After the sputtering glow is stable, the target baffle is opened, and the argon pressure, sputtering power and target-substrate distance are kept stable for 90 minutes. During this process, a circulating water system is used to ensure that the substrate temperature is 363 K, and the TiC-doped alloy is obtained.

[0162] The TiC-doped alloy film obtained in this embodiment has a thickness of 3.9 μm and a columnar crystal structure. The atomic percentage contents of the components are: TiC 70.00 wt %, W 30.00 wt %.

[0163] In actual engineering practice, the components included in the TiC alloy film and the mass percentage of each component are: TiC ≥ 70%, W ≤ 30%, and the content of each of the two can fluctuate within this range.

[0164] In the above embodiments, 7075Al alloy is selected as the matrix material, and 7075Al alloy is the actual armature material.

[0165] Figure 1It is a schematic diagram of the cross-sectional profile of the copper alloy sample after the arc ablation experiment in the embodiment of the present invention. It can be seen from the figure that the height of the ablation product adhered to the surface of the same copper alloy sample when compared with the tungsten film sample is low, and the amount of the ablation product is small, while the height of the ablation product adhered to the surface when compared with the 7075Al alloy substrate is arc ablated. Figure 2 2 is a schematic diagram of the cross-sectional profile of the tungsten film sample and the 7075Al alloy substrate after arc ablation experiment in the embodiment of the present invention. It can be seen from the figure that the ablation pit depth of the tungsten film sample is shallow, while the ablation pit depth of the 7075Al alloy substrate is deep. Combining the two figures, it can be seen that the presence of the tungsten film can effectively reduce the ablation of the 7075Al alloy substrate, reduce the adhesion of the ablation product on the copper alloy surface, and improve the arc ablation resistance.

[0166] Figure 3 It is the adhesion amount of different material films and 7075Al substrate on copper alloy after the friction and wear test in the embodiment of the present invention. It can be seen from the figure that the adhesion amount of different material system films selected by the present invention on the copper alloy surface after the friction and wear test is less than that of the 7075Al substrate, and the adhesion amount to the copper alloy is effectively reduced by 3 to 16 times.

[0167] Figure 4 It is the friction coefficient of the friction between the different material films and the 7075Al substrate and the copper alloy in the embodiment of the present invention. It can be seen from the figure that the friction coefficient of the friction between the different material system films selected by the present invention and the copper alloy is lower than that when the 7075Al substrate and the copper alloy are rubbed together, which effectively improves the friction and wear performance.

[0168] Figure 5 3D white light interference diagram of the copper alloy surface after the rubbing of the Ti-C film and the copper alloy in the embodiment of the present invention. It can be seen from the diagram that the fluctuation of the surface morphology of the copper alloy after the rubbing of the Ti-C film and the copper alloy is Figure 6 3D white light interference diagram of the copper alloy surface after the W film and the copper alloy are rubbed against each other in the embodiment of the present invention. It can be seen from the diagram that the fluctuation degree of the surface morphology of the copper alloy after the W film and the copper alloy are rubbed against each other is Figure 7 316L film and copper alloy are rubbed against each other to form a three-dimensional white light interference diagram of the copper alloy surface. It can be seen from the diagram that the fluctuation of the copper alloy surface morphology after the 316L film and copper alloy are rubbed against each other is Figure 8 This is a three-dimensional white light interference diagram of the copper alloy surface after the 7075 alloy substrate and the copper alloy are rubbed in the embodiment of the present invention. The figure shows the fluctuation of the surface morphology of the copper alloy after the 7075 alloy substrate and the copper alloy are rubbed. By comparison, it can be seen that after the modified film applied by the present invention is rubbed with the copper alloy, the surface fluctuation is lower, and it appears flatter than the 7075 aluminum alloy substrate, with less adhesion.

[0169] Fig. 9 : is a SEM image of the copper alloy surface after the W film and the copper alloy are rubbed against each other in the embodiment of the present invention. It can be seen from the image that the surface morphology of the copper alloy after the W film and the copper alloy are rubbed against each other is: Fig.10 : This is a SEM image of the copper alloy surface after the 7075Al alloy substrate and the copper alloy are rubbed in the embodiment of the present invention. It can be seen from the figure that the surface morphology of the copper alloy and the morphology of the adhesion product after the 7075Al alloy substrate and the copper alloy are rubbed. By comparison, it can be seen that the surface of the copper alloy is relatively smoother after the W film and the copper alloy are rubbed, and there is less adhesion.

[0170] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An electromagnetic railgun armature capable of reducing aluminum adhesion, characterized in that: Its surface has a modified film, which can effectively reduce the aluminum alloy adhesion problem caused by melt deposition during the electromagnetic gun armature launch process. The modified film has positive mixing heat with the copper alloy material of the electromagnetic track and has conductive properties. It has a higher softening temperature and surface hardness than the Al alloy matrix material of the armature itself. It is a pure tungsten film, a pure silver film, a titanium alloy film, a TiC alloy film, a tungsten stainless steel film or a chromium stainless steel film.

2. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 1, characterized in that: The thickness of the modified film is 800nm~8μm.

3. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 2, characterized in that: The modified membrane has a columnar crystal structure.

4. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 3, characterized in that: The components of pure tungsten film and the mass percentage of each component are: W ≥ 95%, the remainder is inevitable impurities, The components included in the pure silver film and the mass percentage of each component are: Ag ≥ 95%, and the remainder is inevitable impurities.

5. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 3, characterized in that: The titanium alloy film includes components and the mass percentages of the components are: Ti≥70%, C≤30%, the sum of the mass percentages of Ti and C is 100%, and the C content is greater than 0.

6. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 3, characterized in that: The TiC alloy film includes components and the mass percentage of each component is: TiC ≥ 70%, W ≤ 30%, the sum of the mass percentage of TiC and the mass percentage of W is 100%, and the content of W is greater than 0.

7. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 3, characterized in that: The components of tungsten stainless steel film and the mass percentage of each component are: W 40% ~ 60%, Cr 6% ~ 10%, Ni 5% ~ 10%, Mn 0.5% ~ 2%, Si 0.1% ~ 1%, Mo 0.5% ~2%, C 0.01 ~ 0.02%, and the balance is Fe.

8. An electromagnetic railgun armature capable of reducing aluminum adhesion as claimed in claim 3, characterized in that: The components of chromium stainless steel film and the mass percentage of each component are: Cr 16% ~ 20%, Ni 5% ~ 18%, Mn 1% ~ 2%, Si 0.1% ~ 1%, Mo 0.01% ~ 2%, C 0.01 ~0.05%, P 0 ~ 0.05%, S 0 ~ 0.009%, and the balance is Fe.

9. A method for preparing an electromagnetic railgun armature with reduced aluminum adhesion as claimed in any one of claims 1 to 8, characterized in that: It includes the following steps: S1: Powder metallurgy or sintering of materials with required components, and then processing them into target materials; S2: Smooth the surface of the armature and clean and dry it; S3: magnetron sputtering is performed. The parameters of magnetron sputtering are: the background vacuum value is less than or equal to 5×10 -4 Pa, the power is 30W~200W, the target substrate distance is 40mm~100mm, the protective gas pressure is 0.2Pa~6.0Pa, the temperature of the armature surface is 298K~423K, the sputtering time is 30min~300min, and the protective gas is argon.

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