CN117447799B - Self-lubricating layer and preparation method and application thereof - Google Patents

Abstract

The invention belongs to the technical field of metal powder manufacturing products, and particularly relates to a self-lubricating layer and a preparation method and application thereof. The self-lubricating layer provided by the invention consists of a metallurgical layer and a self-lubricating filling material filled in the metallurgical layer; the self-lubricating filling material comprises raw material components of carbon filling material, glass fiber, molybdenum disulfide, nano barium sulfate and polytetrafluoroethylene; the metallurgical layer is adhered to a metal matrix of which the surface needs to be lubricated; the metallurgical layer is a copper or copper alloy metallurgical layer. The self-lubricating layer which is compact and has higher strength is formed by the mutual matching and synergistic effect of the material components, the metallurgical layer and the self-lubricating filling material, the surface friction coefficient is effectively reduced, the bonding strength is high, the hardness is high, the shearing strength is high, the abrasion loss of the elastic belt is low, the elastic belt is not easy to fall off when the self-lubricating layer is applied to the elastic belt, the abrasion loss of the matched bore is low, and the temperature rise of the inner wall of the bore is slow.

Description

A self-lubricating layer and its preparation method and application

Technical field

The invention belongs to the technical field of metal powder manufacturing products, and specifically relates to a self-lubricating layer and its preparation method and application.

Background technique

The ammunition belt is an important component of the projectile structure. It has the functions of centering, sealing the gunpowder gas, and guiding the projectile. It gives the projectile a certain rotational speed by cooperating with the rifling, or plays a centering and sealing role in the terminally guided projectile without rifling. . The performance of the ammunition belt has an important impact on the initial velocity, accuracy and barrel life of the projectile. Traditional ammunition belts are generally made of copper, soft iron and other metal materials. Under the conditions of high chamber pressure and high temperature during projectile launch, the copper bullet belt is severely worn due to its soft texture, which will cause the propellant body to leak, seriously affecting the initial velocity and accuracy of projectile launch measurement. At the same time, the copper bullet belt cuts into the rifling and along the During the high-speed sliding process of the rifling, copper adheres to the rifling due to mechanical friction and extrusion, resulting in copper hanging phenomenon, which increases the resistance of the projectile to squeeze in, seriously affects the projectile launch performance, and shortens the service life of the barrel. The artillery will be used for a period of time. After a period of time, toxic lead-containing copper removal agents are usually used to remove copper, which endangers the health of soldiers. The development and application of soft iron ammunition belts can completely eliminate the phenomenon of copper hanging. Its hardness is relatively large and its own wear is small, which can ensure the normal launch of projectiles. However, it intensifies the wear of the rifling it contacts and shortens the service life of the gun bore. None of these metal ammunition belts can solve the problem of the inner wall of the gun barrel heating up too quickly during firing. The existing metal ammunition belts have high surface friction coefficient and poor shear strength, which easily wears the ammunition belts. At the same time, it will also increase the wear of the rifling and cause the inner wall of the gun bore to heat up too quickly.

Contents of the invention

Therefore, the technical problem to be solved by the present invention is to overcome the existing metal ammunition belt surface friction coefficient in the prior art, which has a high surface friction coefficient, poor shear strength, and is easy to wear the ammunition belt. At the same time, it will also aggravate the wear of the rifling and cause the inner wall of the gun bore to heat up too quickly, etc. defects, thereby providing a self-lubricating layer and its preparation method and application.

The invention provides a self-lubricating layer, which is composed of a metallurgical layer and a self-lubricating filling material filled in the metallurgical layer;

The raw material components of the self-lubricating filling material are composed of carbon filler, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene;

The metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The metallurgical layer is a copper or copper alloy metallurgical layer.

Preferably, the self-lubricating filling material has raw material components in terms of weight percentage: 2-5% carbon filler, 5-15% glass fiber, 0.8-1.2% molybdenum disulfide, 0.5-1% nanometer barium sulfate, The balance is PTFE.

Preferably, the copper or copper alloy metallurgical layer is prepared from copper or copper alloy powder;

The copper or copper alloy powder is spherical powder;

The copper or copper alloy powder is a mixture of at least two copper or copper alloy powders with different mesh sizes;

The components of the copper alloy powder include, by weight percentage: Sn 3-10%, P 0-0.5%, Pb 0-1%, and the balance is copper;

And/or, the carbon filler is selected from at least one of graphite and carbon fiber.

Preferably, the copper or copper alloy powder is a mixture of 300-350 mesh, 200-250 mesh and 100-150 mesh copper or copper alloy powder; the 300-350 mesh, 200-250 mesh and 100-150 mesh copper or copper The mass ratio of alloy powder is 1: (1-3): (1-5);

Alternatively, the copper or copper alloy powder is a mixture of 300-350 mesh and 200-250 mesh copper or copper alloy powder; the mass ratio of the 300-350 mesh and 200-250 mesh copper or copper alloy powder is 1: ( 1-3).

Optionally, the copper or copper alloy powder is a mixture of 300 mesh, 200 mesh and 100 mesh copper or copper alloy powder, and the mass ratio of the 300 mesh, 200 mesh and 100 mesh copper or copper alloy powder is 1:3:5 ;

Alternatively, the copper or copper alloy powder is a mixture of 300 mesh and 200 mesh copper or copper alloy powder; the mass ratio of the 300 mesh and 200 mesh copper or copper alloy powder is 1:3.

Preferably, the thickness of the self-lubricating layer is 0.5-3mm, accounting for 3-10% of the total thickness of the self-lubricating layer and the metal matrix. The inventor found that when the self-lubricating layer accounts for 3-10% of the total thickness of the self-lubricating layer and the metal matrix, it can achieve optimal lubrication without affecting other properties. If the thickness of the self-lubricating layer is too thick, it will reduce the material stiffness, and if it is too thin, it will affect the lubrication effect.

The metal matrix can be selected according to different needs and actual conditions, and is not specifically limited. Optionally, the metal matrix is selected from soft iron or low carbon steel; optionally, the metal matrix is a ring-shaped matrix.

Soft iron is pure iron, with a purity of 99.8-99.9% and a carbon content of no more than 0.0218%.

Mild steel is carbon steel with a carbon content of less than 0.25%. It is also called mild steel because of its low strength, low hardness and softness.

The invention provides a method for preparing the above-mentioned self-lubricating layer, which includes the following steps:

1) Sintering copper or copper alloy powder on the outer surface of the metal matrix through one sintering, cooling to form a copper or copper alloy metallurgical layer;

2) Mix the components of the self-lubricating filling material, roll them onto the surface of the copper or copper alloy metallurgical layer, and perform secondary sintering and cooling;

3) Molding to form the self-lubricating layer.

Preferably, the sintering temperature of the primary sintering in step 1) is 850-950°C, and the primary sintering time is 5-10 hours;

And/or, the sintering thickness of the copper or copper alloy powder in step 1) is 1-5mm;

And/or, the cooling described in step 1) is uniform cooling, and when the temperature is cooled to 200°C, the cooling time used is 1-3h;

And/or, the rolling pressure in step 2) is 3-10MPa, and the rolling pressure is until the thickness of the self-lubricating filling material is 1-2mm;

And/or, the secondary sintering temperature in step 2) is 380-400°C, and the secondary sintering time is 3-5 hours;

And/or, the molding pressure described in step 3) is 20-40MPa, and the thickness of the self-lubricating layer is 0.5-3mm;

Optionally, before and after molding as described in step 3), the thickness reduction rate of the self-lubricating layer is not less than 20%.

Preferably, the primary sintering in step 1) is performed in a mixed atmosphere of reducing gas and inert gas;

And/or, the secondary sintering in step 2) is performed in a mixed atmosphere of reducing gas and inert gas;

And/or, the reducing gas is selected from at least one of hydrogen and carbon monoxide;

and/or, the inert gas is selected from at least one of nitrogen and inert gas;

And/or, the volume ratio of reducing atmosphere and inert gas is 1: (5-40).

The preferred solution is to use a continuous tunnel sintering furnace for atmosphere sintering. Make the carbon filler, glass fiber, molybdenum disulfide, nano-barium sulfate and polytetrafluoroethylene evenly penetrate into the pores of the copper or copper alloy metallurgical layer, so that the above-mentioned self-lubricating filling material is evenly filled in the copper Or in the structure of the copper alloy metallurgical layer, a self-lubricating layer that is closely combined with the base metal and has a certain strength is formed.

The present invention provides an application of the above-mentioned self-lubricating layer or the self-lubricating layer prepared by the above-mentioned preparation method in reducing the friction coefficient of the material surface.

The present invention provides an application of the above-mentioned self-lubricating layer or the self-lubricating layer prepared by the above-mentioned preparation method in metal elastic belts, pistons and/or plungers.

The present invention also provides a self-lubricating metal elastic belt, which includes an annular metal matrix and the above-mentioned self-lubricating layer or the self-lubricating layer prepared by the above-mentioned preparation method;

The material of the annular metal matrix is selected from one of soft iron and low carbon steel.

Optionally, the metal base is the part that is in contact with and assembled with the projectile body, and the self-lubricating layer on the outer surface is the working part that is in contact with the gun bore. The self-lubricating layer on the outer surface prevents contact between the base metal and the rifling or barrel lining during the extrusion process when the projectile is fired. The ammunition belt uses soft iron or low carbon steel as the base body, which has the same expansion coefficient as the cartridge case, good conduction performance (that is, the performance of the rifling causing the projectile to rotate) and sufficient strength.

The technical solution of the present invention has the following advantages:

(1) The self-lubricating layer provided by the present invention is composed of a metallurgical layer and a self-lubricating filling material filled in the metallurgical layer; the raw material components of the self-lubricating filling material include carbon filler, glass fiber, It is composed of molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene; the metallurgical layer is bonded to a metal substrate that needs to lubricate the surface; the metallurgical layer is a copper or copper alloy metallurgical layer. The self-lubricating layer of the present invention fills the copper or copper alloy metallurgical layer with the self-lubricating filling material, which can enhance the strength and bonding strength of the self-lubricating layer, realize the filling of the self-lubricating filling material, and achieve good self-lubricating performance. Reduce the coefficient of friction. Nano-barium sulfate, molybdenum disulfide and polytetrafluoroethylene all have lubricating effects, and glass fiber has the effect of reinforcing material strength and improving material hardness. The present invention uses copper or copper alloy metallurgical layers and self-lubricating filling materials to cooperate with each other, and self-lubricating filling materials. Among the lubricating filling materials, carbon fillers, glass fibers, molybdenum disulfide, nano-barium sulfate and polytetrafluoroethylene are combined with various specific lubricating materials and reinforcing materials to form a dense and high-strength self-lubricating layer. , its surface friction coefficient is effectively reduced, the bonding strength is high, the hardness is high, and the shear strength is high. When applied to the cartridge belt, the cartridge belt has low wear and is not easy to fall off. At the same time, the adapted gun bore has low wear and the inner wall of the gun bore heats up slowly.

(2) The self-lubricating layer provided by the invention, the self-lubricating filling material, in terms of weight percentage, raw material components: 2-5% carbon filler, 5-15% glass fiber, 0.8-1.2% molybdenum disulfide, Nano-barium sulfate 0.5-1%, and the balance is polytetrafluoroethylene; by further controlling the raw material component content of the self-lubricating filling material, the present invention further reduces the friction coefficient of the self-lubricating layer, improves the bonding strength, and increases the hardness. , so that when the self-lubricating layer is applied to the ammunition belt, it further reduces the wear of the ammunition belt and makes it less likely to fall off. At the same time, the wear of the adapted gun bore is further reduced, and the temperature of the inner wall of the gun bore is further slowed down.

(3) In the self-lubricating layer provided by the present invention, the copper or copper alloy metallurgical layer is prepared from copper or copper alloy powder; the copper or copper alloy powder is spherical powder; the copper or copper alloy powder includes at least two A kind of spherical powder with different mesh numbers; the components of the copper alloy powder, by weight percentage, include: Sn 3-10%, P 0-0.5%, Pb 0-1%, and the balance is copper; the copper Or the copper alloy powder is a mixture of 300-350 mesh spherical powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder; the 300-350 mesh spherical powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder The mass ratio is 1: (1-3): (1-5); or, the copper or copper alloy powder is a mixture of 300-350 mesh spherical powder and 200-250 mesh spherical powder; the 300-350 mesh The mass ratio of spherical powder and 200-250 mesh spherical powder is 1: (1-3). The present invention uses the components of copper alloy powder, in terms of weight percentage: Sn 3-10%, P 0-0.5%, Pb 0-1%, and the balance is copper, which can further improve the strength and hardness of the overall material and adjust to suit scenes to be used. The metallurgical layer of the present invention is a copper or copper alloy metallurgical layer. By limiting the raw materials for preparing the copper or copper alloy metallurgical layer, the copper or copper alloy powder is spherical and is easier to form voids, so that the raw material components of the self-lubricating filling material are sufficient. Filled into the copper or copper alloy metallurgical layer to form an embedded structure, which improves the bonding strength and shear strength of the material and is not easy to fall off. Copper or copper alloy powder includes at least two spherical powders with different mesh sizes, which can form irregular pores, either wide at the top and narrow at the bottom, or narrow at the top and wide at the bottom, which helps the raw material components of the self-lubricating filling material to be fully filled into the copper Or the copper alloy metallurgical layer forms an embedded structure, which improves the bonding strength and shear strength of the material, prevents it from falling off easily, enhances the hardness of the self-lubricating layer, and helps reduce the friction coefficient of the self-lubricating layer. It is used in elastic belts to reduce elastic belt wear. amount and bore loss to help reduce the heating rate of the inner wall of the bore; when the copper or copper alloy powder is a mixture of 300-350 mesh spherical powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder; the 300-350 mesh spherical powder When the mass ratio of powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder is 1: (1-3): (1-5), you can go one step further by selecting three types of copper or copper alloy powder with different particle sizes. The formation of irregular pores, either wide at the top and narrow at the bottom, or narrow at the top and wide at the bottom, further helps the raw material components of the self-lubricating filling material to fully fill into the copper or copper alloy metallurgical layer to form an embedded structure, further improving the bonding of the material. Strength and shear strength, making it less likely to fall off; further enhancing the hardness of the self-lubricating layer, further helping to reduce the friction coefficient of the self-lubricating layer, and being used in ammunition belts to further reduce the wear of the ammunition belt and the loss of the barrel, further helping to reduce the inner wall of the barrel Heating rate.

(4) The preparation method of the self-lubricating layer provided by the present invention includes the following steps: 1) Sintering copper or copper alloy powder on the outer surface of the metal matrix through one sintering, cooling to form a copper or copper alloy metallurgical layer; 2) Sintering the self-lubricating layer The components of the lubricating filling material are mixed, rolled to the surface of the copper or copper alloy metallurgical layer, and subjected to secondary sintering and cooling; 3) molding to form the self-lubricating layer. The present invention uses primary sintering and secondary sintering to sinter the components of self-lubricating filling materials such as copper or copper alloy powder and low-boiling point polytetrafluoroethylene on the metal matrix. Compared with one-time direct sintering, the sintering strength can be improved and at the same time Ensure the content of PTFE in the self-lubricating layer, realize the effective use of PTFE, and improve the self-lubricating performance of the material. The role of secondary sintering penetration can make the carbon filler, glass fiber, molybdenum disulfide, nano-barium sulfate and polytetrafluoroethylene more closely combined with the copper or copper alloy metallurgical layer, improve the strength of the self-lubricating layer, and ensure that it is used in elastic belts. No shedding after launch.

(5) The self-lubricating layer provided by the present invention or the self-lubricating layer prepared by the preparation method is used in the piston and/or plunger, which can reduce the friction between the piston and/or plunger and the inner wall of the cavity device, and greatly reduce the friction between the piston and/or plunger and the inner wall of the cavity device. Wear of the inner wall of the cylinder.

(6) The self-lubricating metal elastic belt provided by the present invention includes an annular metal matrix and the self-lubricating layer or the self-lubricating layer prepared by the preparation method; the material of the annular metal matrix is selected from soft iron. , a kind of low carbon steel. The self-lubricating metal ammunition belt provided by the present invention has excellent comprehensive properties such as high lubrication performance, good strength, high temperature resistance, etc., slows down the friction and wear between the ammunition belt material and the barrel, causes less damage to the gun body and greatly reduces copper hanging. , which can ensure shooting accuracy. PTFE directly volatilizes under the high temperature of the barrel during the firing process. Other materials in the metallurgical layer are resistant to high temperatures and will not fall off after firing. The ammunition belt uses soft iron or low carbon steel as the base body, which has the same expansion coefficient as the cartridge case, good conduction performance and sufficient strength. Through the cooperation of the soft iron matrix or the low carbon steel matrix and the metallurgical layer, as well as the joint action of the components of the metallurgical layer, the invention provides an ammunition belt with a certain strength while reducing the wear of the ammunition belt itself and the wear of the gun bore, improving The inner wall of the gun barrel heats up too quickly. It has strong heat resistance and will not fall off after firing. It can be used in the preparation of large-sized, long-range, and high-precision artillery shells. The self-lubricating metal ammunition belt provided by the present invention can quickly fill the barrel or rifling during the squeezing process of the shell in the early stage of firing, has outstanding sealing performance, is stronger than plastic ammunition belts, has high stability when the shells move at high speed, and can be fired continuously. It does not affect the shooting accuracy, increases the amount of shells fired, and extends the maintenance cycle. At the same time, the self-lubricating metal elastic belt provided by the present invention has a metal matrix that is easy to process, and the self-lubricating powder metallurgy layer can realize continuous and batch manufacturing, and has a high cost performance; the elastic belt structure can be adjusted according to actual needs by adjusting the self-lubricating powder metallurgy layer. The thickness, density and related material types can be used to obtain a series of products with different performances to meet the needs of various types of artillery and gun belts.

Detailed ways

The following examples are provided to better understand the present invention. They are not limited to the best embodiments and do not limit the content and protection scope of the present invention. Anyone who is inspired by the present invention or uses the present invention to Any product that is identical or similar to the present invention by combining it with other features of the prior art falls within the protection scope of the present invention.

If no specific experimental steps or conditions are specified in the examples, the procedures can be carried out according to the conventional experimental steps or conditions described in literature in the field. If the manufacturer of the reagents or instruments used is not indicated, they are all conventional reagent products that can be purchased commercially.

The materials used in the following examples and comparative examples of the present invention are as follows: the glass fiber is an alkali-free glass fiber (E-glass fiber) with a diameter of 5-15 μm and a length of 1-3 mm; the particle size of nano-barium sulfate is 50-200 nm, and the purity is > 99%; the degree of polymerization of polytetrafluoroethylene is on the order of 104, and the average particle size is 50 μm; the fiber diameter of carbon fiber is 7-20 μm, and the length is 3-5 mm.

Example 1

This embodiment provides a self-lubricating layer, which is composed of a copper alloy metallurgical layer and a self-lubricating filling material filled in the copper alloy metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, consists of raw material components: 3% graphite, 10% glass fiber, 1% molybdenum disulfide, 0.7% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper alloy metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 8%, P 0.3%, Pb 0.5%, and the balance copper;

The copper alloy spherical powder is a mixture of 300 mesh copper alloy spherical powder, 200 mesh copper alloy spherical powder and 100 mesh copper alloy spherical powder, with a mass ratio of 1:3:5.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 900°C and the sintering time is It takes 7h, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and the time used is 1h when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 4mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 7MPa, the rolling thickness is 1.5mm, the secondary sintering temperature is 390°C, the secondary sintering time is 4h, the secondary sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and cooled;

3) Molding, the molding pressure is 35MPa to form the self-lubricating layer, wherein the thickness of the self-lubricating layer from molding to 2.5mm accounts for 5% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Example 2

This embodiment provides a self-lubricating layer, which is composed of a copper alloy metallurgical layer and a self-lubricating filling material filled in the copper alloy metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, consists of raw material components: 2% graphite, 5% glass fiber, 0.8% molybdenum disulfide, 0.5% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper alloy metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 3% and the balance copper;

The copper alloy spherical powder is a mixture of 300 mesh copper alloy spherical powder, 200 mesh copper alloy spherical powder and 100 mesh copper alloy spherical powder, with a mass ratio of 1:1:1.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 850°C and the sintering time is It is 5h, the sintering atmosphere is carbon monoxide and nitrogen (volume ratio 1:25), and the time used is 1.5h when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 2mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 10MPa, the rolling thickness is 1mm, the secondary sintering temperature is 380°C, the sintering time is 3h, the secondary sintering atmosphere is carbon monoxide and nitrogen (volume ratio 1:25), and cooled;

3) Molding, the molding pressure is 40MPa to form the self-lubricating layer, wherein the thickness of the self-lubricating layer from molding to 0.5mm accounts for 10% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Example 3

This embodiment provides a self-lubricating layer, which is composed of a copper alloy metallurgical layer and a self-lubricating filling material filled in the copper alloy metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, consists of raw material components: 5% graphite, 15% glass fiber, 1.2% molybdenum disulfide, 1% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper alloy metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 10%, P 0.5%, Pb 1%, and the balance copper;

The copper alloy spherical powder is a mixture of 300 mesh copper alloy spherical powder, 200 mesh copper alloy spherical powder and 100 mesh copper alloy spherical powder, with a mass ratio of 1:2:5.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 950°C and the sintering time is It takes 10 hours, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:40), and the time used is 3 hours when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 5mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 3MPa, the rolling thickness is 2mm, the secondary sintering temperature is 400°C, the sintering time is 4h, the secondary sintering atmosphere is hydrogen and nitrogen (volume ratio 1:40), and cooled;

3) Molding, the molding pressure is 20MPa to form the self-lubricating layer, wherein the thickness of the self-lubricating layer from molding to 3mm accounts for 10% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Example 4

This embodiment provides a self-lubricating layer, which is composed of a copper alloy metallurgical layer and a self-lubricating filling material filled in the copper alloy metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, includes raw material components: 3% carbon fiber, 10% glass fiber, 1% molybdenum disulfide, 0.7% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper alloy metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 8%, Pb 0.5%, and the balance copper;

The copper alloy spherical powder is a mixture of 300 mesh copper alloy spherical powder, 200 mesh copper alloy spherical powder and 100 mesh copper alloy spherical powder, with a mass ratio of 1:3:5.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 900°C and the sintering time is It takes 7h, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and the time used is 1h when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 4mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 7MPa, the rolling thickness is 1.5mm, the secondary sintering temperature is 390°C, the sintering time is 4h, the secondary sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and cooled;

3) Molding, the molding pressure is 35MPa to form the self-lubricating layer, wherein the thickness of the self-lubricating layer from molding to 2.5mm accounts for 3% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Example 5

This embodiment provides a self-lubricating layer, which is composed of a copper metallurgical layer and a self-lubricating filling material filled in the copper metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, consists of raw material components: 3% carbon fiber, 10% glass fiber, 1% molybdenum disulfide, 0.7% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper metallurgical layer is prepared from copper spherical powder; the copper spherical powder is a mixture of 300-mesh copper spherical powder, 200-mesh copper spherical powder and 100-mesh copper spherical powder, with a mass ratio of 1:3:5.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 900°C and the sintering time is 7h, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and the time used is 1h when the temperature is uniformly cooled to 200°C to form a copper metallurgical layer. The sintering thickness of the copper metallurgical layer is 4mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 7MPa, the rolling thickness is 1.5mm, the secondary sintering temperature is 390°C, the sintering time is 4h, the secondary sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and cooled;

3) Molding. The molding pressure is 35MPa to form the self-lubricating layer. The thickness of the self-lubricating layer from molding to 2.5mm accounts for 7% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Example 6

This embodiment provides a self-lubricating layer, which is composed of a copper alloy metallurgical layer and a self-lubricating filling material filled in the copper alloy metallurgical layer;

The self-lubricating filling material, in terms of weight percentage, consists of raw material components: 3% graphite, 10% glass fiber, 1% molybdenum disulfide, 0.7% nanometer barium sulfate, and the balance is polytetrafluoroethylene;

The copper alloy metallurgical layer is bonded to a metal substrate that requires a lubricated surface;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 8%, P 0.3%, Pb 0.5%, and the balance copper;

Copper alloy spherical powder is a mixture of 300-mesh copper alloy spherical powder and 200-mesh copper alloy spherical powder, with a mass ratio of 1:3.

This embodiment provides a method for preparing a self-lubricating layer, which includes the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 900°C and the sintering time is It takes 7h, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and the time used is 1h when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 4mm;

2) Mix graphite, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene according to the specified proportion, roll it to the surface of the copper alloy metallurgical layer, and then put it into the atmosphere sintering furnace for secondary sintering. The rolling pressure is 7MPa, the rolling thickness is 1.5mm, the secondary sintering temperature is 390°C, the sintering time is 4h, the secondary sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and cooled;

3) Molding, the molding pressure is 35MPa to form the self-lubricating layer, wherein the thickness of the self-lubricating layer from molding to 2.5mm accounts for 5% of the total thickness of the self-lubricating layer and the annular soft iron matrix.

Comparative example 1

This comparative example provides a lubricating layer, which is a copper alloy metallurgical layer;

The copper alloy metallurgical layer is prepared from copper alloy spherical powder; the components of the copper alloy spherical powder are, by weight percentage: Sn 8%, P 0.3%, Pb 0.5%, and the balance copper;

The copper alloy spherical powder is a mixture of 300 mesh copper alloy spherical powder, 200 mesh copper alloy spherical powder and 100 mesh copper alloy spherical powder, with a mass ratio of 1:3:5.

This comparative example provides a preparation method for the lubricating layer, including the following steps:

1) The soft iron matrix (carbon content is 0.02%) is processed into a ring shape, and the copper alloy spherical powder is sintered on the outer surface of the ring-shaped soft iron matrix through one sintering in a continuous tunnel sintering furnace. The sintering temperature is 900°C and the sintering time is It takes 7h, the sintering atmosphere is hydrogen and nitrogen (volume ratio 1:6), and the time used is 1h when the temperature is uniformly cooled to 200°C to form a copper alloy metallurgical layer. The sintering thickness of the copper alloy metallurgical layer is 4mm;

2) Molding, the molding pressure is 35MPa to form the lubricating layer, wherein the thickness of the lubricating layer is 2.5mm, accounting for 5% of the total thickness of the lubricating layer and the annular soft iron matrix.

Comparative example 2

This comparative example provides a self-lubricating layer. Compared with Example 1, the only difference is that the raw material components of the self-lubricating filling material do not include polytetrafluoroethylene, and the proportions of other raw material components remain unchanged.

This comparative example provides a method for preparing a self-lubricating layer. Compared with Example 1, the only difference is that polytetrafluoroethylene is not added in step 2).

Comparative example 3

This comparative example provides a self-lubricating layer. Compared with Example 1, the only difference is that the raw material components of the self-lubricating filling material do not include nanometer barium sulfate, and the proportions of other raw material components remain unchanged.

This comparative example provides a method for preparing a self-lubricating layer. Compared with Example 1, the only difference is that in step 2), nanometer barium sulfate is not added.

Comparative example 4

This comparative example provides a self-lubricating layer. Compared with Example 1, the only difference is that the raw material components of the self-lubricating filling material do not include molybdenum disulfide, and the proportions of other raw material components remain unchanged.

This comparative example provides a method for preparing a self-lubricating layer. Compared with Example 1, the only difference is that molybdenum disulfide is not added in step 2).

test case

The self-lubricating layers prepared in all examples and the lubricating layers or self-lubricating layers prepared in comparative examples were subjected to the following tests: friction coefficient test on the surface of the self-lubricating layer, test standard: ASTM G 133-22; hardness test of the self-lubricating layer, test Standard: "Metal Brinell Hardness Test" (GB/T231.1-2002); Shear strength test of self-lubricating layer, test standard: "Method for determination of shear strength of sintered bimetallic materials" (YS/T 485-2005 ).

The self-lubricating layer prepared in all examples and the lubricating layer or self-lubricating layer prepared in the comparative example, as well as the annular metal soft iron matrix inside the whole body, are precision processed using CNC equipment to process the inner circle, and complete chamfering and other precision processing. A self-lubricating metal simulated ammunition belt is obtained when the required dimensions are met. Simulate shooting on the self-lubricating metal simulated ammunition belt, use the weighing method to measure the wear of the simulated ammunition belt, simulate shooting 10 times in a row, use the weighing method to measure the loss of the simulated rifling, and use an infrared thermal imaging camera to detect the temperature of the inner wall of the gun bore Increase the amplitude, and record whether the simulated ammunition belt falls off after being ejected. The test results are shown in Table 1.

Table 1

Obviously, the above-mentioned embodiments are only examples for clear explanation and are not intended to limit the implementation. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. An exhaustive list of all implementations is neither necessary nor possible. The obvious changes or modifications derived therefrom are still within the protection scope of the present invention.

Claims (9)

1. A self-lubricating layer, characterized in that the self-lubricating layer consists of a metallurgical layer and a self-lubricating filling material filled in the metallurgical layer; The raw material components of the self-lubricating filling material are composed of carbon filler, glass fiber, molybdenum disulfide, nanometer barium sulfate and polytetrafluoroethylene; The metallurgical layer is bonded to a metal substrate that requires a lubricated surface; The metallurgical layer is a copper or copper alloy metallurgical layer; The self-lubricating filling material, in terms of weight percentage, has raw material components: 2-5% carbon filler, 5-15% glass fiber, 0.8-1.2% molybdenum disulfide, 0.5-1% nanometer barium sulfate, and the balance is PTFE; The carbon filler is selected from at least one of graphite and carbon fiber; The metallurgical layer is prepared from copper or copper alloy powder; The copper or copper alloy powder is a mixture of 300-350 mesh spherical powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder. 2. The self-lubricating layer according to claim 1, characterized in that the components of the copper alloy powder, by weight percentage: Sn 3-10%, P 0-0.5%, Pb 0-1%, the remainder The amount is copper. 3. The self-lubricating layer according to claim 2, characterized in that the mass ratio of the 300-350 mesh spherical powder, 200-250 mesh spherical powder and 100-150 mesh spherical powder is 1: (1-3) : (1-5). 4. The self-lubricating layer according to claim 1, characterized in that the thickness of the self-lubricating layer is 0.5-3mm, accounting for 3-10% of the total thickness of the self-lubricating layer and the metal matrix; And/or, the metal matrix is selected from soft iron or low carbon steel; And/or, the metal matrix is a cyclic matrix. 5. A method for preparing a self-lubricating layer according to any one of claims 1 to 4, characterized in that it includes the following steps: 1) Sintering copper or copper alloy powder on the outer surface of the metal matrix through one sintering, cooling to form a copper or copper alloy metallurgical layer; 2) Mix the components of the self-lubricating filling material, roll them onto the surface of the copper or copper alloy metallurgical layer, and perform secondary sintering and cooling; 3) Molding to form the self-lubricating layer. 6. The preparation method of the self-lubricating layer according to claim 5, characterized in that the sintering temperature of the primary sintering in step 1) is 850-950°C, and the primary sintering time is 5-10h; And/or, the sintering thickness of the copper or copper alloy metallurgical layer in step 1) is 1-5mm; And/or, the cooling described in step 1) is uniform cooling, and when the temperature is cooled to 200°C, the cooling time used is 1-3h; And/or, the rolling pressure in step 2) is 3-10MPa, and the rolling pressure is until the thickness of the self-lubricating filling material is 1-2mm; And/or, the secondary sintering temperature in step 2) is 380-400°C, and the secondary sintering time is 3-5 hours; And/or, the molding pressure described in step 3) is 20-40MPa, and the thickness of the self-lubricating layer is 0.5-3mm; And/or, the primary sintering in step 1) is performed in a mixed atmosphere of reducing gas and inert gas; And/or, the secondary sintering in step 2) is performed in a mixed atmosphere of reducing gas and inert gas; And/or, the reducing gas is selected from at least one of hydrogen and carbon monoxide; and/or, the inert gas is selected from at least one of nitrogen and inert gas; And/or, the volume ratio of reducing atmosphere and inert gas is 1: (5-40). 7. Application of the self-lubricating layer according to any one of claims 1 to 4 or the self-lubricating layer prepared by the preparation method according to claims 5 or 6 in reducing the friction coefficient of the material surface. 8. Application of the self-lubricating layer according to any one of claims 1 to 4 or the self-lubricating layer prepared by the preparation method according to claims 5 or 6 in metal elastic belts, pistons and/or plungers. 9. A self-lubricating metal elastic belt, characterized in that it includes an annular metal matrix and a self-lubricating layer according to any one of claims 1-4 or a self-lubricating layer prepared by the preparation method according to claims 5 or 6. layer; The material of the annular metal matrix is selected from one of soft iron and low carbon steel.