CN114030248A

CN114030248A - Metal reinforced composite material with elastic layer and preparation method thereof

Info

Publication number: CN114030248A
Application number: CN202010699463.7A
Authority: CN
Inventors: 樊学峰; 孙志华; 陆忠泉
Original assignee: Zhejiang Changsheng Sliding Bearings Co Ltd
Current assignee: Zhejiang Changsheng Sliding Bearings Co Ltd
Priority date: 2020-07-20
Filing date: 2020-07-20
Publication date: 2022-02-11

Abstract

The invention provides a metal reinforced composite material with an elastic layer and a preparation method thereof. The metal reinforced composite material comprises a metal substrate, an elastic layer and a sliding layer, wherein the elastic layer is positioned between the metal substrate and the sliding layer, the elastic layer comprises a metal net and a sliding layer material filled in meshes of the metal net, the metal net is connected to the metal substrate through sintering, and the sliding layer material comprises polytetrafluoroethylene, a reinforcing material, a solid lubricant and optional nanoparticles. The sliding layer of the metal reinforced composite material has the advantages of good compactness, no bubbles, thick thickness, capability of turning, good plate bonding strength, good wear resistance, strong self-lubricating capability, high bearing capacity, impact resistance, high temperature resistance and corrosion resistance, and is particularly suitable for producing sliding parts.

Description

Metal reinforced composite material with elastic layer and preparation method thereof

Technical Field

The invention belongs to the technical field of sliding bearing materials, and particularly relates to a metal reinforced composite material with an elastic layer and a preparation method thereof.

Background

In the transmission operation system, the shaft transmission system is used in various important operation links as a basic and most common transmission operation technology. In the automobile production industry, a shaft sleeve is an extremely important component, in particular to an automobile door hinge bush, the bush is fixed with an automobile hinge and is arranged between a shaft and a shaft support, and the shaft and the bush are in a close fit state so as to increase certain torque. The automobile door hinge lining can play a self-lubricating role in the opening and closing motion process of the automobile door, and the opening and closing of the automobile door has certain damping, so that the end of the hinge shaft is uniformly stressed, the abrasion is greatly reduced, the torque attenuation is slowed down, the stability and the service life of the hinge mechanism are improved, and the stable opening and closing of the automobile door, no abnormal sound and comfort are ensured.

At present, a lubricating bushing is generally made of a metal-based composite wear-resistant material, and various problems of thin wear-resistant sliding layer, poor torque, poor compactness, short wear-resistant time, easy aging of a binder, more abrasive dust on a wear-resistant layer and the like of the metal-based composite wear-resistant material in the prior art are not solved, so that the lubricating bushing is still replaced at an excessively high frequency, and the maintenance cost of mechanical equipment is excessively high.

In recent years, the domestic market usually uses a steel plate as a support, wear-resistant material PTFE is paved on the steel plate, the steel plate is plasticized and sintered, and then the steel plate is rolled into a shaft sleeve, and lubricating oil can be not added, so that the shaft sleeve can replace a copper sleeve and a powder metallurgy sleeve, but the following problems still exist: the wear-resistant sliding layer is thin, and the wear-resistant time is short. If the wear-resistant sliding layer is thickened, the wear-resistant sliding layer is not firmly sintered, peeled and even falls off.

Later, bearings have been produced by integrating a metal mesh and a metal plate through a sintering process, and then infiltrating a plastic material in the form of an aqueous emulsion or a dry powder into the metal mesh through a mechanical rolling process. Once the sliding layer of the bearing manufactured by the method is thick, bubbles can be generated in the sliding layer, the bonding strength between layers is reduced, and the wear resistance and the lubricating property of the material are reduced; the sliding layer is porous and has poor compactness, which affects the uniformity of the whole thickness of the bearing and the service life of the bearing.

At present, the copper mesh is adhered to a steel plate through an adhesive in foreign countries, and then an abrasion-resistant sliding layer is adhered to a plate-shaped copper mesh. The manufacturing method has the following defects: the shaft sleeve made of the plate has low bonding strength between the copper mesh and the steel plate, and when the shaft sleeve is corroded by the environment or generates high temperature due to load bearing, the binder can age rapidly, so that the steel plate substrate is separated from the copper mesh, finally, the wear-resistant sliding layer is failed rapidly, and the manufacturing cost of the plate-shaped copper mesh is high.

Therefore, there is still a need in the art for a metal-reinforced composite material for a sliding bearing, which has a sliding layer with good compactness, is firmly sintered, is not easy to fall off, can be thickened and turned, has high bonding strength between a metal mesh and a metal substrate, is not easy to separate, and has good stability and a long service life.

Disclosure of Invention

In order to solve various problems of the existing bushing made of composite materials, the invention provides a novel metal reinforced composite material with an elastic layer and a manufacturing method thereof. Unlike gluing, the present invention uses a metal mesh (e.g., copper mesh) sintered to a metal plate (e.g., steel plate) to achieve a metallurgical bond with higher bond strength and without the problem of aging of the adhesive. Compared with the composite material manufactured by adopting the common process of steel backing, copper powder and PTFE, the sliding layer of the sliding material is thicker and more compact, the inner hole of the shaft sleeve can be turned for improving the assembly precision, and the copper mesh layer is more elastic than the copper powder layer, so that the torque attenuation is favorably reduced, and the service life of the shaft sleeve is prolonged.

Specifically, the invention provides a metal reinforced composite material with an elastic layer, which comprises a metal substrate, the elastic layer and a sliding layer, wherein the elastic layer is positioned between the metal substrate and the sliding layer, the elastic layer comprises a metal net and a sliding layer material filled in meshes of the metal net, the metal net is connected to the metal substrate through sintering, the sliding layer is made of the same material as the sliding layer material filled in the meshes of the metal net, the sliding layer material comprises polytetrafluoroethylene, a reinforcing material, a solid lubricant and optional nano particles, and the polytetrafluoroethylene is derived from polytetrafluoroethylene dispersed powder.

In one or more embodiments, the metal substrate is a steel plate.

In one or more embodiments, the metal mesh is a copper mesh.

In one or more embodiments, the metal substrate has a thickness of 0.5 to 2.5 mm.

In one or more embodiments, the elastic layer has a thickness of 0.2 to 0.5 mm.

In one or more embodiments, the volume of the sliding layer material in the elastic layer is 40% to 70% of the total volume of the elastic layer.

In one or more embodiments, the sliding layer has a thickness of 0.1mm or more, preferably 0.2mm or more.

In one or more embodiments, the polytetrafluoroethylene is contained in the sliding layer material in an amount of 60 to 80 wt% based on the total weight of the sliding layer material.

In one or more embodiments, the content of the reinforcing material in the sliding layer material is 1 to 10 wt% based on the total weight of the sliding layer material.

In one or more embodiments, the content of the solid lubricant in the sliding layer material is 8 to 30 wt% based on the total weight of the sliding layer material.

In one or more embodiments, the optional nanoparticles are present in the sliding layer material in an amount of 0.1 to 10 wt.%, based on the total weight of the sliding layer material.

In one or more embodiments, the reinforcing material is selected from one or more of carbon fibers, glass fibers, and reinforced polymers; preferably, the reinforcing polymer is selected from one or more of nylon, polyester, aramid fiber, polyimide, polyaryletherketone, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyarylsulfone and polyethersulfone.

In one or more embodiments, the solid lubricant is selected from graphite, MoS₂One or more of graphite fluoride, boron nitride, sodium fluoride, cerium fluoride, lithium fluoride, calcium fluoride, barium sulfate, aluminum oxide, calcium phosphate, calcium sulfate, calcium fluoride, and zinc oxide.

In one or more embodiments, the nanoparticles are selected from one or both of silica nanoparticles and calcium oxide nanoparticles.

In one or more embodiments, the sliding layer and the sliding layer material filled in the meshes of the metal mesh are formed by laying an oily polymer slurry comprising a resin composition comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, and an oily solvent on the surface and meshes of the metal mesh attached to a metal substrate, followed by drying and sintering.

In one or more embodiments, the sliding layer and the sliding layer material filled in the meshes of the metal mesh are formed by laminating a composite green tape including polytetrafluoroethylene, a reinforcing material, a solid lubricant, and optionally nanoparticles, on the surface of the metal mesh attached to the metal substrate and in the meshes, and sintering.

The present invention also provides a method for preparing a metal-reinforced composite material having an elastic layer according to any one of the embodiments of the present invention, the method comprising the steps of drying and sintering an oily polymer slurry laid on the surface and in the meshes of a metal mesh attached to a metal substrate, the oily polymer slurry comprising a resin composition and an oily solvent, the resin composition comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, the polytetrafluoroethylene being a polytetrafluoroethylene dispersed powder.

In one or more embodiments, the metal mesh is attached to the metal substrate by sintering at a temperature of 800-; preferably, the sintering time is 10-25 minutes; preferably, the sintering is protected by using a mixed gas of an inert gas and a reducing gas, such as a hydrogen-nitrogen mixed gas; in the hydrogen-nitrogen mixed gas, the volume ratio of hydrogen to nitrogen is preferably 5: 1 to 2: 1.

in one or more embodiments, the polytetrafluoroethylene is present in the resin composition in an amount of 60 to 80 wt%, based on the total weight of the resin composition.

In one or more embodiments, the reinforcing material is present in the resin composition in an amount of 1 to 10 wt% based on the total weight of the resin composition.

In one or more embodiments, the solid lubricant is contained in the resin composition in an amount of 8 to 30 wt% based on the total weight of the resin composition.

In one or more embodiments, the optional nanoparticles are present in the resin composition in an amount of 0.1 to 10 wt%, based on the total weight of the resin composition.

In one or more embodiments, the oily solvent is selected from any one or a mixture of any more of kerosene, white oil, naphtha, petroleum-based solvents, naphthenic solvents, and aliphatic solvents; preferably, the oily solvent comprises kerosene, white oil, crude gasoline and a petroleum-based solvent, wherein the content of the kerosene is preferably 5-40 wt%, the content of the white oil is preferably 3-20 wt%, the content of the crude gasoline is preferably 20-60 wt%, the content of the petroleum-based solvent is preferably 16-32 wt%, and the petroleum-based solvent is preferably petroleum ether.

In one or more embodiments, the oily polymer slurry has a solid content of 75 to 85 wt%.

In one or more embodiments, the oily polymer slurry is obtained by mixing a mixture comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, and the oily solvent; the mixture is preferably obtained by mixing at-10 to-5 ℃; preferably, before the oily solvent and the mixture are mixed, the mixture is dried, the drying time is preferably 30 minutes to 1 hour, and the drying temperature is preferably 100 ℃ to 110 ℃.

In one or more embodiments, the temperature for drying the oily polymer slurry laid on the meshes and surface of the metal mesh is 180 to 250 ℃.

In one or more embodiments, after the oily polymer slurry is laid on the meshes and surface of the metal mesh and before drying, the whole of the metal mesh and the metal substrate on which the oily polymer slurry is laid may be cold rolled.

In one or more embodiments, the composite raw material belt which is covered and pressed on the meshes and the surface of the metal net is sintered, and the sintering temperature is 380-400 ℃; the sintering time is preferably 15-30 minutes; preferably, the sintering is protected by a mixed gas of an inert gas and a reducing gas, for example, a mixed atmosphere of hydrogen and nitrogen.

The present invention also provides another method of preparing a metal-reinforced composite material having an elastic layer according to any one of the embodiments of the present invention, the method comprising the step of sintering a composite green tape comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, the polytetrafluoroethylene being a polytetrafluoroethylene dispersion powder, which is laminated on the surface and in the meshes of a metal mesh attached to a metal substrate.

In one or more embodiments, the metal mesh is attached to the metal substrate by sintering at a temperature of 800-; preferably, the sintering time is 10-25 minutes; preferably, the protection is performed by using a mixed gas of an inert gas and a reducing gas, for example, a hydrogen-nitrogen mixed gas, during sintering.

In one or more embodiments, the polytetrafluoroethylene content in the composite raw material tape is 60-80 wt% based on the total weight of the composite raw material tape.

In one or more embodiments, the reinforcing material is present in the composite raw material tape in an amount of 1 to 10 wt%, based on the total weight of the composite raw material tape.

In one or more embodiments, the solid lubricant is present in the composite raw material tape in an amount of 8 to 30 wt% based on the total weight of the composite raw material tape.

In one or more embodiments, the optional nanoparticles are present in the composite green tape in an amount of 0.1 to 10 wt%, based on the total weight of the composite green tape.

In one or more embodiments, the composite green tape is formed from a blend comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant, and optionally nanoparticles, pressed into a green body and extruded in the form of a strip; the mixture is preferably obtained by mixing at-10 to-5 ℃.

In one or more embodiments, the composite green tape has a thickness of 0.5 to 1 mm.

In one or more embodiments, the composite raw material tape is dried before being laminated on the meshes and the surface of the metal mesh, and the drying temperature is preferably about 100 to 110 ℃, and the time is preferably 30min to 1 hour.

The present invention also provides a sliding member comprising the metal-reinforced composite material according to any one of the embodiments of the present invention or a metal-reinforced composite material produced by the method according to any one of the embodiments of the present invention; preferably, the sliding component is a bushing, a flanged bearing, a gasket or a backing plate.

The invention also provides application of the polytetrafluoroethylene dispersion powder in preparing the metal reinforced composite material or improving the compactness of a sliding layer, the thickness of the sliding layer, the turning property, the wear resistance, the self-lubricating capacity, the high temperature resistance and/or the corrosion resistance of the metal reinforced composite material.

The invention also provides the application of the composite raw material belt or the oily polymer slurry in preparing the metal reinforced composite material or improving the compactness of a sliding layer, the thickness of the sliding layer, the turning property, the wear resistance, the self-lubricating capability, the high temperature resistance and/or the corrosion resistance of the metal reinforced composite material, wherein the composite raw material belt or the oily polymer slurry contains polytetrafluoroethylene dispersed powder; preferably, the oily polymer slurry or the composite green tape is as described in any embodiment herein.

Drawings

Fig. 1 is a schematic view showing a pattern of a sample in test example 2, wherein the left side is a side view and the right side is a plan view, a represents a liner flange outer diameter, B represents a liner height, and C represents a liner outer diameter.

Fig. 2 is a schematic physical photograph of the sample in test example 2.

FIG. 3 is a metallographic micrograph of a cross section of a sample in test example 2.

Fig. 4 shows the dimensional and geometric accuracy requirements of the test block in test example 4, where a represents the reference plane,

represents flatness,// represents parallelism.

Fig. 5 is a schematic view of the peel performance test of the test piece in test example 5.

Detailed Description

To make the features and effects of the present invention comprehensible to those skilled in the art, general description and definitions are made below with reference to terms and expressions mentioned in the specification and claims. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

The theory or mechanism described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, i.e., the present disclosure may be practiced without limitation to any particular theory or mechanism.

All features defined herein as numerical ranges or percentage ranges, such as amounts, amounts and concentrations, are for brevity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to cover and specifically disclose all possible subranges and individual numerical values (including integers and fractions) within the range.

Herein, unless otherwise specified, the ratio refers to a mass ratio, and the percentage refers to a mass percentage.

In this context, for the sake of brevity, not all possible combinations of features in the various embodiments or examples are described. Therefore, the respective features in the respective embodiments or examples may be arbitrarily combined as long as there is no contradiction between the combinations of the features, and all the possible combinations should be considered as the scope of the present specification.

The existing composite material for the sliding bearing has various problems of thin wear-resistant sliding layer, poor compactness, short wear-resistant time, easy aging of a binder and the like, so that the replacement frequency of a lubricating bushing is too high, and the maintenance cost of mechanical equipment is too high. In order to solve the problems, the metal substrate and the metal mesh (including woven mesh and punched mesh) are sintered (metallurgical bonding is formed), and the lubricating layer is laid by adopting a composite raw material belt process (uncured) or a direct paste extrusion mode, so that the metal reinforced composite material and the preparation method thereof have the following advantages: the sliding layer has better compactness and thicker thickness and can be turned; the plate has good bonding strength, good wear resistance, strong self-lubricating capability, high bearing capacity, impact resistance, high temperature resistance and corrosion resistance; can realize the flow line production, the production cost is low, green.

The metal reinforced composite material comprises a metal substrate, a metal mesh layer (elastic layer) and a sliding layer or consists of the metal substrate, the metal mesh layer and the sliding layer, wherein the metal mesh layer is positioned between the metal substrate and the sliding layer, the metal mesh layer comprises a metal mesh and a sliding layer material filled in meshes of the metal mesh or consists of the metal mesh and the sliding layer material filled in the meshes of the metal mesh, and the metal mesh is connected onto the metal substrate through sintering.

Metal substrates suitable for use in the present invention include, but are not limited to, steel sheets, copper sheets, aluminum sheets, stainless steel sheets, and the like. In a preferred embodiment, the metal substrate used in the present invention is a steel plate; the steel sheet is preferably a passivated steel sheet. The thickness of the metal substrate is preferably 0.5 to 2.5 mm. In a preferred embodiment, the invention uses high quality carbon structural steel cold rolled steel sheets or strips, for example 08, 08F, such as SPCC, SPCD cold rolled steel sheets and strips produced by Bao Steel group.

In the present invention, the thickness of the metal mesh layer is preferably 0.2 to 0.5 mm. The content (volume ratio) of the sliding layer material in the metal mesh layer is preferably 40% to 70%. The type of the metal mesh suitable for the present invention is not particularly limited, and may be, for example, a woven mesh, a punched mesh. Materials suitable for the metal mesh of the present invention include, but are not limited to, steel mesh, copper mesh, aluminum mesh, stainless steel mesh, and the like. In some embodiments, the metal mesh used in the present invention is a copper mesh, such as a punched copper mesh, a woven copper mesh. It is understood that the copper mesh described herein includes copper alloy mesh. Expanded metal (e.g., woven mesh, punched mesh) suitable for use in the present invention may be obtained from commercially available sources, such as the commercially available QSn6.5-0.1, QSn8-0.3 copper alloy mesh, or may be prepared by methods known in the art, such as expanded metal from sheet metal. The mesh shape of the metal net is not particularly limited, and may be, for example, a diamond shape, a square shape, a circular shape, a semicircular shape, or the like. In the invention, the metal mesh layer has certain elasticity and can improve the impact resistance of the metal reinforced composite material, so the metal mesh layer is also called as an elastic layer.

In the present invention, when sintering the metal mesh (e.g. copper mesh) and the metal substrate (e.g. steel plate), the sintering temperature is preferably 800-1000 deg.C, such as 880-920 deg.C, and the sintering time is preferably 10-25 minutes. In this case, the sintering is preferably performed under a mixed gas of an inert gas and a reducing gas, for example, a nitrogen-hydrogen mixed gas. In the nitrogen-hydrogen mixed gas, the volume ratio of hydrogen to nitrogen is preferably 5: 1 to 2: 1, e.g., 3: about 1. In some embodiments, the invention lays a metal mesh (such as a copper mesh) on a metal substrate (such as a steel plate, preferably a passivated steel plate), and puts the metal mesh into a sintering furnace to sinter into a whole, wherein the sintering is protected from oxidation by a mixed hydrogen-nitrogen atmosphere, the sintering temperature is 900 +/-20 ℃, and the sintering time is 10-25 minutes. After sintering, a metallurgical bond is formed between the metal mesh and the metal substrate.

As can be understood by those skilled in the art, the sliding layer and the sliding layer filled in the mesh of the metal mesh are made of the same material and are integrally formed. Therefore, in the text, when "sliding layer material" is described, the corresponding description applies to both the sliding layer and the sliding layer material filled in the mesh of the metal mesh, unless otherwise specified.

The sliding layer material of the metal reinforced composite material of the present invention comprises polytetrafluoroethylene, and the polytetrafluoroethylene is preferably polytetrafluoroethylene dispersed powder. In some embodiments, the sliding layer material of the present invention comprises or consists of polytetrafluoroethylene, a reinforcing material, a solid lubricant, and optionally nanoparticles.

The polytetrafluoroethylene used in the invention is polytetrafluoroethylene powder. The polytetrafluoroethylene powder comprises polytetrafluoroethylene synthesized by a suspension method and polytetrafluoroethylene synthesized by an emulsion method. Both of these polytetrafluoroethylene are well known in the art and can be prepared by methods known in the art. In general, polytetrafluoroethylene synthesized by the suspension method is called polytetrafluoroethylene suspension powder, and polytetrafluoroethylene synthesized by the emulsion method is called polytetrafluoroethylene dispersion powder. The present invention preferably uses polytetrafluoroethylene synthesized by an emulsion method, i.e., polytetrafluoroethylene dispersed powder. Polytetrafluoroethylene dispersion powders are commercially available, and may be, for example, Polyflon F201, F104 manufactured by Daikin Logio, Co., Ltd., Teflon 6CJ manufactured by Mitsui dupont Fluorochemical, Ltd., and polytetrafluoroethylene dispersion powders manufactured by Zhonghao Chenguang, Shandong Yue, Zhejiang Juhua, etc. The average particle diameter of the polytetrafluoroethylene dispersion powder is preferably 400-600. mu.m, for example, about 500. mu.m. The present inventors have found that thicker and denser sliding layers can be achieved using the dispersed powder. In the sliding layer material, the content of polytetrafluoroethylene is preferably 60-80 wt%, such as 65-80 wt%, 65-78 wt%.

The reinforcing material suitable for the present invention is not particularly limited, and may be a reinforcing material commonly used for preparing sliding materials, including but not limited to carbon fibers, glass fibers, reinforced polymers, and the like. Examples of reinforcing polymers include, but are not limited to, nylon, polyester, aramid fibers, polyimide, polyaryletherketone, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyarylsulfone, polyethersulfone, and the like. The size of the reinforcing material (e.g., the diameter and length of the fiber) depends on the kind of the reinforcing material, and may be determined as required, and for example, the diameter of the carbon fiber is preferably 7 to 8 μm, and the length is preferably 80 to 150 μm. In a preferred embodiment, the reinforcing material is carbon and/or aramid fibers. In the sliding layer material, the content of the reinforcing material is preferably 1 to 10 wt%, for example, 5 to 10 wt%, 5 to 8 wt%. The addition of the reinforcing material is beneficial to improving the bearing and wear-resisting properties of the polytetrafluoroethylene material.

The solid lubricant suitable for use in the present invention is not particularly limited, and may be a solid lubricant commonly used for preparing sliding materials, including but not limited to graphite, MoS₂Graphite fluoride, boron nitride, sodium fluoride, cerium fluoride, lithium fluoride, calcium fluoride, barium sulfate, aluminum oxide, calcium phosphate, calcium sulfate, calcium fluoride, zinc oxide, and the like. The content of the solid lubricant in the sliding layer material is preferably 8 to 30 wt%, for example, 10 to 25 wt%, 15 to 25 wt%. In a preferred embodiment, the solid lubricant is one or more, preferably two or more, selected from the group consisting of aluminum oxide, calcium fluoride, graphite, and barium sulfate, for example, aluminum oxide and calcium fluoride, graphite and barium sulfate, or aluminum oxide and barium sulfate. The particle size of the aluminum oxide and calcium fluoride is preferably 30 μm or less, for example 10 μm or less. The particle size of the graphite is preferably 30 to 50 μm.The particle size of barium sulfate is preferably 1000 mesh or less, and more preferably 1250 mesh or less.

The nanoparticles suitable for use in the present invention are not particularly limited, and are preferably one or both of silica nanoparticles and calcium oxide nanoparticles. When included, the content of the nanoparticles in the sliding layer material is preferably 0.1 to 10 wt%, for example 0.5 to 5 wt%, 1 to 3 wt%. The particle size of the nanoparticles is preferably 50 to 200 nm. In a preferred embodiment, the sliding layer material comprises nanoparticles. The solid lubricant and the nano-particles in the sliding layer material can generate a friction chemical reaction with the surface of the metal coupling in the friction process, so that a friction film or a transfer film with high coverage and high bearing capacity is formed on the surface of the metal coupling. The strength of the friction film or the transfer film is higher than that of the reinforced material, so that the reinforced material can be prevented from being damaged, the friction coefficient of a friction system can be obviously reduced, meanwhile, the wear resistance of a sliding layer is improved, and particularly, in the application of an automobile door hinge, the friction and wear performance of the material can be improved, and the torque attenuation and the sinking amount of a door can be favorably reduced.

In some embodiments, the sliding layer material comprises 60 to 80 wt%, such as 65 to 80 wt%, 65 to 78 wt% of polytetrafluoroethylene, 1 to 10 wt%, such as 5 to 10 wt%, 5 to 8 wt% of reinforcing material, 8 to 30 wt%, such as 10 to 25 wt%, 15 to 25 wt% of solid lubricant, and 0.1 to 10 wt%, such as 0.5 to 5 wt%, 1 to 3 wt% of optional nanoparticles.

The components and the proportion of the sliding layer material are optimized and blended, so that the metal reinforced composite material has the advantages of good sliding layer compactness, no bubbles, thick thickness, turning capability, good wear resistance, strong self-lubricating capability, high bearing capability, impact resistance, high temperature resistance, corrosion resistance and the like.

In the present invention, the sliding layer and the sliding layer material filled in the meshes of the metal mesh are formed by laminating the composite raw material tape on the surface and meshes of the metal mesh attached to the metal substrate and sintering, or formed by spreading the oily polymer slurry on the surface and meshes of the metal mesh attached to the metal substrate and drying and sintering.

The invention directly sinters a metal mesh (such as a copper mesh) on a metal substrate (such as a steel plate), then a layer of composite raw material belt is covered and pressed on the metal mesh (such as the copper mesh) to form a metal reinforced composite material whole body through sintering, and the composite raw material belt is melted at high temperature and permeates into an inner hole of the copper mesh and the surface of the copper mesh; or, the oily polymer slurry is laid on a metal net, and the metal reinforced composite material is formed by drying and sintering. The thickness of the sliding layer of the metal reinforced sliding material prepared by the method can exceed 0.3mm, and the compactness is excellent; the thickness of the sliding layer of the metal reinforced sliding material prepared by adopting the common process of the steel backing, the copper powder and the PTFE is generally 0.01-0.03mm, and the maximum thickness is not more than 0.05mm, otherwise, the sliding layer is easy to peel and delaminate, and the binding force is reduced. In a preferred embodiment, the sliding layer of the metal-reinforced sliding material of the present invention has a thickness of 0.05mm or more, for example, 0.1mm or more, 0.2mm or more, 0.3mm or more, and the like.

Composite raw material tapes suitable for use in the present invention comprise polytetrafluoroethylene, preferably polytetrafluoroethylene dispersion powder. In some embodiments, a composite green tape suitable for use in the present invention comprises or consists of polytetrafluoroethylene, a reinforcing material, a solid lubricant, and optionally nanoparticles; in the composite raw material tape, the content of polytetrafluoroethylene is preferably 60-80 wt%, the content of reinforcing materials is preferably 1-10 wt%, the content of solid lubricants is preferably 8-30 wt%, and the content of optional nanoparticles is preferably 0.1-10 wt%. The thickness of the composite raw material belt is matched according to the required thickness of the sliding layer, and is generally 0.5-1 mm.

In the present invention, the composite raw material tape may be made of a resin composition.

The resin composition suitable for preparing the composite raw material tape comprises polytetrafluoroethylene, and the polytetrafluoroethylene is preferably polytetrafluoroethylene dispersion powder. The invention discovers that the polytetrafluoroethylene suspension powder cannot be extruded to form the composite raw material belt when being used as the polytetrafluoroethylene raw material, and the polytetrafluoroethylene dispersion powder can be successfully used for preparing the composite raw material belt. In some embodiments, a resin composition suitable for use in the present invention comprises or consists of polytetrafluoroethylene, a reinforcing material, a solid lubricant, and optionally nanoparticles; in the resin composition, the content of polytetrafluoroethylene is preferably 60-80 wt%, the content of reinforcing material is preferably 1-10 wt%, the content of solid lubricant is preferably 8-30 wt%, and the content of optional nanoparticles is preferably 0.1-10 wt%.

In the present invention, the polytetrafluoroethylene, the reinforcing material, the solid lubricant and the nanoparticles in the composite raw material tape and the resin composition for preparing the composite raw material tape may be the polytetrafluoroethylene, the reinforcing material, the solid lubricant and the nanoparticles in the sliding layer material described in any of the above embodiments and their contents, which are not described herein again.

In the present invention, the composite raw material tape may be formed by pressing the resin composition into a green body and then extruding the green body in the form of a long strip. In some embodiments, the composite green tape is prepared by: the components of the resin composition are mixed and stirred uniformly, the mixture is placed into an ultrasonic vibration sieve, the materials are sieved and scattered, and the materials are pressed into a green body and extruded in a strip form to form the unsintered composite raw material belt.

Preferably, the components of the resin composition are mixed at low temperature (e.g., in a low temperature blender); the stirring temperature is preferably-10 ℃ to-5 ℃; the rotating speed of the stirrer is preferably 2000-3000 rpm; the stirring time is preferably 8 to 15 minutes. The components of the resin composition are stirred at low temperature (-10 ℃ to-5 ℃) to enable the polytetrafluoroethylene to be in a sand shape, so that intermolecular diffusion between the polytetrafluoroethylene and the added filler is facilitated, agglomeration of the resin composition during stirring is avoided, and the resin composition is dispersed more uniformly.

Preferably, the composite raw material tape is dried before being laminated on the meshes and the surface of the metal mesh. The drying temperature is preferably about 100-110 ℃, and the drying time is preferably about 30 min-1 hour.

It can be understood that, when the composite raw material tape is laminated on the mesh and the surface of the metal mesh, the laminating pressure should be such that a uniform resin composition is formed on the side of the metal mesh not connected to the metal substrate, and the mesh of the metal mesh is filled with the resin composition, and those skilled in the art can adjust the laminating pressure according to the required thickness of the sliding layer.

In the invention, when the composite raw material belt which is covered and pressed on the meshes and the surface of the metal net is sintered, the sintering temperature is preferably 380-400 ℃, for example 390 +/-5 ℃; the sintering time is preferably 15 to 30 minutes, for example 20 to 30 minutes; it is preferable to protect the sintering with a mixed gas of an inert gas and a reducing gas, for example, a mixed atmosphere of hydrogen and nitrogen.

In some embodiments, the metal-reinforced composite of the present invention is prepared by:

(1) spreading a copper net on a passivated steel plate, putting the passivated steel plate into a sintering furnace, and sintering the passivated steel plate into a whole at the sintering temperature of 900 +/-50 ℃ for 10-25 minutes;

(2) uniformly mixing and stirring the components of the resin composition to obtain a mixture, wherein the stirring temperature is-10 to-5 ℃, and the rotating speed of a stirrer is 2000 to 3000 rpm; placing the mixture into an ultrasonic vibration sieve, sieving and scattering the materials, pressing the materials into a green body, and extruding the green body in a strip form to form an unsintered composite raw material belt;

(3) drying the composite raw material belt, covering and pressing the dried composite raw material belt on the inner hole and the surface of a copper net for sintering, wherein the sintering temperature is 390 +/-5 ℃, the time is 20-30 minutes, and the hydrogen-nitrogen mixed atmosphere is protected;

thereby obtaining the metal reinforced composite material.

The oily polymer slurry suitable for use in the present invention comprises or consists of a resin composition and an oily solvent. The resin composition in the oily polymer slurry may be the resin composition as described in any of the embodiments above for the preparation of the composite green tape. It is understood that the resin composition in the oily polymer slurry is a powder before being mixed with the oily solvent. It is understood that the oily polymer slurry used in the present invention is a paste in a sludge state at normal temperature. The solid content of the oily polymer slurry used in the invention is preferably 75-85 wt%.

The differences between the present invention and the conventional wet fluorine process for producing a metal-reinforced sliding material include: in one aspect, the conventional wet fluorine method is to lay an aqueous PTFE emulsion on the surface and in the meshes of a copper mesh, while the invention uses an oily solvent; on the other hand, the conventional wet fluorine uses PTFE suspension powder, while the present invention uses PTFE dispersion powder, which is easily agglomerated and is not suitable for use in an aqueous emulsion, and the present invention has found that a sliding layer made of the dispersion powder can achieve a thicker and denser effect.

Preferably, in the resin composition of the oily polymer slurry, the content of polytetrafluoroethylene is 60 to 80 wt%, and the polytetrafluoroethylene is preferably polytetrafluoroethylene dispersed powder. In some embodiments, the resin composition suitable for the oily polymer slurry of the present invention comprises or consists of polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles; in the resin composition of the oily polymer slurry, the content of polytetrafluoroethylene is preferably 60 to 80 wt%, the content of the reinforcing material is preferably 1 to 10 wt%, the content of the solid lubricant is preferably 8 to 20 wt%, and the content of the optional nano-particles is preferably 0.1 to 10 wt%.

The oily solvent contained in the oily polymer slurry suitable for use in the present invention may be any one or a mixture of any more of kerosene, white oil, naphtha, petroleum-based solvent, naphthenic solvent and aliphatic solvent. The petroleum-based solvent may be, for example, petroleum ether. When contained, the content of kerosene is preferably 5 to 40 wt%, the content of white oil is preferably 3 to 20 wt%, the content of naphtha is preferably 20 to 60 wt%, the content of petroleum-based solvent is preferably 16 to 32 wt%, the content of naphthenic solvent is preferably 14 to 25 wt%, and the content of aliphatic solvent is preferably 17 to 54 wt% in the oily solvent. In some embodiments, the oily solvent comprises or consists of kerosene, white oil, naphtha and petroleum-based solvent, wherein the kerosene is preferably 5 to 40 wt%, more preferably 25 to 35 wt%, the white oil is preferably 3 to 20 wt%, more preferably 10 to 18 wt%, the naphtha is preferably 20 to 60 wt%, more preferably 25 to 35 wt%, the petroleum-based solvent is preferably 16 to 32 wt%, more preferably 20 to 30 wt%, and the petroleum-based solvent is preferably petroleum ether.

The invention discovers that PTFE dispersed powder is not easy to agglomerate in oily polymer slurry by adopting the oily solvent mixed resin composition, and a prepared sliding layer can obtain thicker and more compact effect; in addition, the solid lubricant and the nano particles can be fully dispersed in the oily solvent and fully mixed with the PTFE dispersion powder so as to fully generate the tribochemical reaction.

In the present invention, the oily polymer slurry may be made from the resin composition described herein and the oily solvent described herein. In some embodiments, the oily polymer slurry is prepared by: the components of the resin composition are mixed and stirred uniformly to obtain a mixture, and the mixture and the oily solvent are stirred uniformly to present an oily slurry state, so that oily polymer slurry is obtained. The amount ratio (mass ratio) of the resin composition to the oily solvent is preferably 75: 25 to 85: 15.

preferably, the components of the resin composition are mixed at low temperature (e.g., in a low temperature blender); the stirring temperature is preferably-10 ℃ to-5 ℃; the rotating speed of the stirrer is preferably 2000-3000 rpm; the stirring time is preferably 8 to 15 minutes.

Preferably, the mixture is dried before the oily solvent and the mixture are mixed; the drying time is preferably 30 minutes to 1 hour, and the drying temperature is preferably 100 to 110 ℃.

When the oily polymer slurry is laid on the mesh and surface of the metal net, the thickness of the oily polymer slurry laid on the surface of the metal net is matched according to the thickness required for the sliding layer, and may be, for example, 0.5 to 1 mm.

In the invention, the temperature for drying the oily polymer slurry laid on the meshes and the surface of the metal net is preferably 180-250 ℃, and the drying time is preferably 20-30 minutes. The drying is performed to remove the oily solvent from the oily polymer slurry.

After the oily polymer slurry is laid on the meshes and the surface of the metal net and before drying, the metal net and the metal substrate which are laid with the oily polymer slurry can be integrally cold rolled. It is understood that the pressure during the cold rolling is such that a uniform layer of oily polymer slurry is formed on the side of the metal mesh not connected to the metal substrate, and the meshes of the metal mesh are filled with the oily polymer slurry, and those skilled in the art can adjust the pressure during the cold rolling according to the required thickness of the sliding layer. After cold rolling, the thickness of the oily polymer slurry on top of the metal mesh is matched to the desired thickness of the sliding layer, typically 0.5-1 mm.

In the invention, when the dried oily polymer slurry covered and pressed on the meshes and the surface of the metal net is sintered, the sintering temperature is preferably 380-400 ℃, for example 390 +/-5 ℃; the sintering time is preferably 15 to 30 minutes, for example 20 to 30 minutes; it is preferable to protect the sintering with a mixed gas of an inert gas and a reducing gas, for example, a mixed atmosphere of hydrogen and nitrogen.

(1) laying a copper mesh on a passivated steel plate, putting the steel plate into a sintering furnace, and sintering the steel plate into a whole at the sintering temperature of 900 +/-50 ℃ for 10-25 minutes;

(2) uniformly mixing and stirring the components of the resin composition to obtain a mixture, wherein the stirring temperature is-10 to-5 ℃, and the rotating speed of a stirrer is 2000 to 3000 rpm; uniformly stirring the mixture and an oily solvent to form oily slurry, thereby obtaining oily polymer slurry; preferably, before the oily solvent and the mixture are mixed, the mixture is dried;

(3) laying the oily polymer slurry on meshes and surfaces of a metal net, and performing cold rolling;

(4) drying the oily polymer slurry laid on the meshes and the surface of the metal net at the drying temperature of 180-250 ℃ for 20-30 minutes;

(5) sintering the dried oily polymer slurry laid on the meshes and the surface of the metal net at 390 +/-5 ℃ for 20-30 minutes in a hydrogen-nitrogen mixed atmosphere;

thereby obtaining the metal reinforced composite material.

The metal reinforced composite material and the preparation method thereof have the following advantages: the sliding layer has good compactness, no air bubble and thick thickness, and can be turned; the plate has good bonding strength, no adhesive, good wear resistance, strong self-lubricating capability, high bearing capacity, impact resistance, high temperature resistance and corrosion resistance; the production cost is low, the environment is protected, the method is suitable for industrial flow line production, and the efficiency is high.

The above advantages of the metal reinforced composite material of the present invention make it particularly suitable for use in the manufacture of sliding parts such as bushings, flanged bearings, gaskets, pads and the like. The lubricating bush made of the metal reinforced composite material is particularly suitable for the working conditions of long-term non-oil maintenance, such as rotary motion and swinging motion under high load and low speed, and frequent opening and closing under load and difficult formation of fluid lubrication, such as application to automobile door hinge systems, automobile steering gear systems, industrial compressors and the like. Accordingly, the present invention includes sliding components, including but not limited to bushings, flanged bearings, gaskets, cauls, and the like, made using the metal reinforced composite of the present invention.

Compared with the prior art, the lubricating bushing made of the metal reinforced composite material has the advantages that:

1) the sliding layer of the lubricating bushing is good in compactness and excellent in wear resistance, so that the torque attenuation of the hinge mechanism in application is favorably slowed down, the stability of the hinge mechanism is improved, and the service life of the hinge mechanism is prolonged;

2) the sliding layer of the lubricating bushing is thick in thickness and can be turned, and the requirements of strict fit clearance and tightness between the bushing and a shaft in the hinge mechanism are met; the friction fabric of the sliding layer is different from the traditional three-layer composite process (such as steel plate + copper powder + PTFE, steel plate + copper mesh + wet fluorine), can be thickened to 0.3mm, and the inner hole of the shaft sleeve can be turned and bored;

3) the lubricating bushing has good bonding strength, does not use a binder, and does not have the phenomena of binder aging and separation of a steel plate and a copper mesh;

4) the noise reduction and the shock absorption are realized, the user experience is good, and the development trend of the current social technology is met.

The present invention will be further described with reference to specific examples. The scope of the present invention is not limited by the contents of the following examples. The scope of the present invention is defined only by the appended claims, and any omissions, substitutions, and changes in the form of the embodiments disclosed herein that may be made by those skilled in the art are intended to be included within the scope of the present invention.

The following examples and comparative examples use equipment conventional in the art. The experimental methods and the detection methods, in which specific conditions are not noted in the following examples and comparative examples, are generally performed according to conventional conditions or according to conditions recommended by manufacturers. The various starting materials used in the following examples and comparative examples, unless otherwise specified, were conventional commercially available products. In the description of the present invention and the following examples and comparative examples, "%" represents weight percent, "parts" represents parts by weight, and ratios represent weight ratios, unless otherwise specified.

The raw materials used in the examples and comparative examples are illustrated below:

(1) polytetrafluoroethylene:

polytetrafluoroethylene dispersion powder: polyflon F201 (average particle size 500 μm) of Daikin (Daikin Logyo. Co., Ltd.);

(2) reinforcing fibers:

carbon fiber: CM80-3.0/200-UN (filament diameter 7 μm, length 80 μm) from Sigli, Germany;

aramid fiber: twaron 5011, a japan imperial corporation;

(3) solid lubricant:

aluminum oxide: the particle size is less than 10 mu m in common market;

calcium fluoride: the particle size is less than 10 um;

graphite: crystalline flake graphite of Nanjing Zhining company, the particle size is 30-50 μm;

barium sulfate: zibo Yichangming pigment Co., Ltd, 1250 mesh;

(4) nano-particles:

nano silicon dioxide: the particle size of the product is 50-100nm, and is produced by Tanshinanta hong Chengda New Material Co., Ltd;

(5) copper mesh: a commercially available QSn6.5-0.1 copper alloy mesh;

(6) steel plate: SPCC cold rolled steel sheet produced by Bao Steel group, the mark is 08.

Example 1: metal reinforced composite material prepared by adopting composite raw material belt process

The formulation of the resin composition of this example was: 75 wt% of polytetrafluoroethylene dispersion powder, 5 wt% of carbon fiber, 7 wt% of aluminum oxide, 10 wt% of calcium fluoride and 3 wt% of nano silicon dioxide.

The metal reinforced composite material is prepared by the following process:

(1) spreading a copper net on a passivated steel plate, putting the passivated steel plate into a sintering furnace, sintering the passivated steel plate into a whole at the sintering temperature of 900 ℃ for 15 minutes in a volume ratio of 3: 1, protecting hydrogen and nitrogen mixed atmosphere;

(2) mixing the components of the resin composition in a low-temperature mixer to obtain a mixture, wherein the stirring temperature of the low-temperature mixer is-5 ℃, the rotating speed of the mixer is 2500rpm, and the stirring time is 10 minutes; placing the mixture into an ultrasonic vibration sieve, sieving and scattering the materials, pressing the materials into a blank body, and extruding the blank body in a strip form to form an unsintered composite raw material belt, wherein the thickness of the composite raw material belt is about 0.8 mm;

(3) drying the composite raw material tape at the drying temperature of 110 ℃ for 30 min; and (3) pressing the dried composite raw material belt on the inner hole and the surface of the copper mesh for sintering, wherein the sintering temperature is 390 ℃, the time is 25 minutes, and the volume ratio is 3: 1, protecting hydrogen and nitrogen mixed atmosphere;

thereby obtaining the metal reinforced composite material.

Example 2: metal reinforced composite material prepared by adopting composite raw material belt process

The formulation of the resin composition of this example was: 76 wt% of polytetrafluoroethylene dispersion powder, 3 wt% of carbon fiber, 3 wt% of aramid fiber, 5 wt% of graphite, 10 wt% of barium sulfate and 3 wt% of nano silicon dioxide.

The metal reinforced composite material is prepared by the following process:

thereby obtaining the metal reinforced composite material.

Example 3: metal reinforced composite material prepared by adopting composite raw material belt process

The formulation of the resin composition of this example was: 78 wt% of polytetrafluoroethylene dispersion powder, 5 wt% of aramid fiber, 5 wt% of graphite, 10 wt% of barium sulfate and 2 wt% of nano silicon dioxide.

The metal reinforced composite material is prepared by the following process:

thereby obtaining the metal reinforced composite material.

Example 4: preparation of metal reinforced composite material by adopting oily polymer slurry process

The formulation of the oily solvent of this example is: 30 wt% of kerosene, 15 wt% of white oil, 30 wt% of crude gasoline and 25 wt% of petroleum ether.

The metal reinforced composite material is prepared by the following process:

(1) spreading a copper net on a passivated steel plate, putting the steel plate into a sintering furnace, sintering the steel plate into a whole at the sintering temperature of 910 ℃ for 15 minutes in a volume ratio of 3: 1, protecting hydrogen and nitrogen mixed atmosphere;

(2) mixing the components of the resin composition in a low-temperature mixer to obtain a mixture, wherein the stirring temperature of the low-temperature mixer is-6 ℃, the rotating speed of the mixer is 2800rpm, and the stirring time is 10 min; drying the mixture at 110 deg.C for 30 min; mixing the dried mixture with an oily solvent according to the ratio of 75: 25 by weight percent and presents an oily slurry shape to obtain oily polymer slurry;

(3) spreading the oily polymer slurry on the meshes and the surface of the copper mesh, and performing cold rolling, wherein the thickness of the oily polymer slurry on the copper mesh is about 0.8 mm;

(4) drying the oily polymer slurry laid on the meshes and the surface of the copper mesh at the drying temperature of 230 ℃ for 25 minutes;

(5) sintering the dried oily polymer slurry laid on the meshes and the surface of the copper mesh at 390 ℃ for 30 minutes in a volume ratio of 3: 1, protecting hydrogen and nitrogen mixed atmosphere;

thereby obtaining the metal reinforced composite material.

Example 5: preparation of metal reinforced composite material by adopting oily polymer slurry process

The metal reinforced composite material is prepared by the following process:

thereby obtaining the metal reinforced composite material.

Example 6: preparation of metal reinforced composite material by adopting oily polymer slurry process

The metal reinforced composite material is prepared by the following process:

thereby obtaining the metal reinforced composite material.

Comparative example 1: preparation of metal reinforced composite material by traditional wet fluorine process

The formula of the resin composition is as follows: 75 wt% of polytetrafluoroethylene suspension powder (DF-102 suspension powder in east Shandong), 5 wt% of carbon fiber, 7 wt% of aluminum oxide, 10 wt% of calcium fluoride and 3 wt% of nano silicon dioxide.

PTFE dispersion: the sky is morning light SFN-1.

The preparation process comprises the following steps:

(2) uniformly mixing all the components of the resin composition in a low-temperature mixer to obtain a mixture, wherein the mixing temperature of the low-temperature mixer is-5 ℃, the rotating speed of the mixer is 2500rpm, and the mixing time is 10 minutes; mixing the mixture and PTFE dispersion liquid (mass ratio is 4: 1) to form slurry, laying the slurry on a copper mesh layer, performing cold rolling, wherein the thickness of the slurry on the copper mesh layer after rolling is about 0.8mm, and drying after rolling at the drying temperature of 310 ℃ for 20 min. And (3) sintering the dried plate in a nitrogen furnace at 395 ℃ for 90min in a volume ratio of 3: 1 under the protection of hydrogen-nitrogen mixed atmosphere. And (5) performing finish rolling and leveling on the sintered plate.

Comparative example 2: preparation of metal reinforced composite material by gluing process

The preparation process comprises the following steps:

(1) spreading a copper net on a passivated steel plate, putting the passivated steel plate into a sintering furnace, sintering the passivated steel plate into a whole at the sintering temperature of 900 ℃ for 15 minutes in a volume ratio of 3: 1, protecting in a hydrogen-nitrogen mixed atmosphere to obtain a steel plate copper mesh;

(2) uniformly mixing all the components of the resin compound in a low-temperature stirrer according to the formula, wherein the stirring temperature of the low-temperature stirrer is-5 ℃, the rotating speed of the stirrer is 2500rpm, the stirring time is 10 minutes, and then pressing and sintering are carried out, wherein the sintering temperature is 395 ℃, the time is more than 200 hours, and the volume ratio is 3: 1, and sintering the blank under the protection of hydrogen-nitrogen mixed atmosphere. Then turning into a PTFE film (soft belt) with the thickness of about 0.2 mm. The soft tape was glued to a steel sheet copper mesh using fluoropolymer (ETFE).

Test example 1: sliding layer compactness

The sliding layer compactness of the metal reinforced composite materials prepared in examples 1 to 6 and comparative example 1 was examined by an ultrasonic zero-gravity test.

And (3) testing conditions are as follows: sample size: 50mm × 50mm × δ mm (δ is the actual thickness of the plate); test medium: distilled water; diameter of a probe of an ultrasonic generator: 35 mm; measuring head spacing: 1.3 mm; frequency: 20 KHz; time: and 5 min. After the test, the weight loss of the sliding layer was measured.

And (3) testing results: the weight loss of the sliding layer of the metal reinforced composite material (comparative example 1) prepared by the traditional wet fluorine process is 10 mg; the weight loss of the sliding layer of the metal-reinforced composite material (examples 1 to 6) prepared by the method of the present invention was within 3 mg.

Test example 2: thickness of sliding layer

The metal reinforced composite materials prepared in examples 1 to 6 and comparative example 1 were prepared into samples, the apparent morphology of the cross section was observed with a metallographic microscope, the magnification was 100X, and the thickness of the sliding layer was measured.

The sample is in the form shown in fig. 1, and a schematic physical photograph of the sample is shown in fig. 2. The cross-sectional morphology of the sample piece observed under a metallographic microscope is shown in fig. 3.

And (3) testing results: the sliding layer thickness of the metal reinforced composite material (comparative example 1) prepared by the traditional wet fluorine process was 0.02 mm; the sliding layer thickness of the metal-reinforced composite material (examples 1 to 6) prepared by the method of the present invention was about 0.2 mm.

Test example 3: sliding layer turning ability

The metal reinforced composite materials prepared in examples 1 to 6 and comparative example 1 were subjected to turning.

Judgment standard of sliding layer cutting machining: the cutting force is moderate in the process of cutting the sliding layer by using the cutter, the surface of the sliding layer is smooth after cutting, the chip breaking performance is good, and the sliding layer is not loosened and flaked.

And (3) testing results: the sliding layer of the metal reinforced composite material (comparative example 1) prepared by the traditional wet fluorine process cannot be turned; the sliding layers of the metal-reinforced composite materials (examples 1-6) prepared by the method of the present invention were lathed, thereby improving the assembly accuracy.

Test example 4: tribological properties

The metal reinforced composite materials prepared in examples 1 to 6 and comparative examples 1 to 2 were prepared into samples and subjected to an end face friction performance test by the following method:

sample size: the size of the test block is 37mm multiplied by delta mm (delta is the actual thickness of the plate), and the geometric precision requirement of the test block is specified according to the figure 4;

and (3) grinding a part: the material is 45# steel, the hardness is 43-47 HRC, the roughness Ra0.4, and the grinding piece is a circular ring: the inner diameter is 22mm, and the outer diameter is 30 mm;

ambient temperature: normal temperature (20 + -5 deg.C);

and (3) testing conditions are as follows: the load P is 15MPa, the speed V is 0.2m/s, the disposable coating (3# lithium-based grease) is applied, and the test time t is 3 h.

And (3) testing results: the results of the tribological property tests of the metal-reinforced composite materials prepared by the method of the present invention (examples 1 to 6) and the metal-reinforced composite materials of comparative examples 1 to 2 are shown in table 1.

Table 1: results of experimental tribological Properties of Metal-reinforced composite materials of examples 1-6 and comparative examples 1-2

Test example 5: bonding strength

The metal reinforced composite materials prepared in examples 1 to 6 and comparative examples 1 to 2 were prepared into test pieces, and a peel strength test was performed to evaluate the bonding strength, the test method being as follows:

test piece size: the width of the test piece is 10mm, the rest sizes, the test piece types and the stripping modes of the test piece are shown in fig. 5, and in fig. 5, the metal mesh sliding composite layer refers to that the metal mesh layer and the sliding layer are stripped from the metal substrate together as a whole;

the test method comprises the following steps: the test method specified in method 1 of GB/T2792-2014 was referred to and the peeling speed was 20 mm/min.

The peel strength was calculated according to formula (1):

in formula (1): r_chThe peel strength is given in N/cm; f is the minimum load when the soft belt layer is stripped, and the unit is N; and B is the combined width of the steel base and the soft belt and has the unit of cm.

And (3) testing results: the results of the peel strength tests of the metal-reinforced composites (examples 1 to 6) prepared by the method of the present invention and the metal-reinforced composites of comparative examples 1 to 2 are shown in table 2. As can be seen from table 2, the peel strength of the present invention is significantly better than the soft tape gluing process, but comparable to conventional wet fluorine.

Table 2: peeling Strength test results of Metal-reinforced composite materials of examples 1-6 and comparative examples 1-2

Test example 6: high temperature resistance

The metal reinforced composite materials prepared in examples 1 to 6 and comparative examples 1 to 2 were subjected to a high temperature compression performance test to evaluate the high temperature resistance, the test method being as follows:

and (3) manufacturing a test piece: the test piece is made of a metal reinforced composite material, and the size of the metal reinforced composite material is not specified.

The test piece requirements are as follows: the test piece was wiped clean with an acetone cotton ball before and after the test.

Test conditions and operations:

four test pieces were taken for the following tests, respectively:

at 100N/mm²Measuring the thickness change of the sliding layer after keeping the pressure at (23 +/-2) DEG C for 1 hour under the pressure;

at 100N/mm²Measuring the thickness change of the sliding layer after keeping the pressure at (100 +/-2) DEG C for 1 hour under the pressure;

at 300N/mm²Measuring the thickness change of the sliding layer after keeping the pressure at (23 +/-2) DEG C for 1 hour under the pressure;

at 300N/mm²The thickness change of the sliding layer was measured after holding the pressure at (100. + -. 2) ℃ for 1 hour under pressure.

The measuring method comprises the following steps: after holding the temperature and pressure, directly unloading and cooling at room temperature for more than 15min, and measuring under the condition of no load.

The results of the high temperature compression property test are shown in table 3.

Table 3: experimental results of high temperature compression Properties of Metal-reinforced composite materials of comparative examples 1-2 and examples 1-6

Test example 7: corrosion resistance

The metal reinforced composite materials prepared in example 1 and comparative example 1 were subjected to a chemical stability test to evaluate corrosion resistance, the test method being as follows:

Test conditions and operations:

four test pieces were taken for the following tests, respectively:

measuring the weight change of the test piece after soaking in water at 90 +/-2 ℃ for 48 hours;

measuring the weight change of the test piece after soaking in water at the temperature of (23 +/-2) DEG C for 100 hours;

measuring the weight change of the test piece after soaking in oil at 90 +/-2 ℃ for 24 hours;

the weight change of the test piece was measured after soaking in oil at (23. + -. 2). degree.C for 48 hours.

The medium requirements are as follows:

water: distilled water is adopted;

oil: the oil for the system is completely consumed by adopting L-AN32, and meets the regulation of GB 443.

The chemical stability test results are shown in table 4.

Table 4: chemical stability test results of the Metal-reinforced composite materials of comparative examples 1-2 and examples 1-6

Claims

1. A metal-reinforced composite material having an elastic layer, comprising a metal substrate, an elastic layer and a sliding layer, wherein the elastic layer is disposed between the metal substrate and the sliding layer, the elastic layer comprises a metal mesh and a sliding layer material filled in meshes of the metal mesh, the metal mesh is connected to the metal substrate by sintering, the sliding layer material is the same as the sliding layer material filled in the meshes of the metal mesh, the sliding layer material comprises polytetrafluoroethylene (ptfe) derived from a ptfe dispersed powder, a reinforcing material, a solid lubricant and optionally nanoparticles.

2. The metal-reinforced composite with an elastic layer of claim 1, wherein the metal-reinforced composite has one or more of the following characteristics:

(1) the metal substrate is a steel plate;

(2) the metal net is a copper net;

(3) the thickness of the metal substrate is 0.5-2.5 mm;

(4) the thickness of the elastic layer is 0.2-0.5 mm;

(5) in the elastic layer, the volume of the sliding layer material is 40-70% of the total volume of the elastic layer;

(6) the thickness of the sliding layer is more than or equal to 0.1mm, preferably more than or equal to 0.2 mm;

(7) the content of the polytetrafluoroethylene in the sliding layer material is 60-80 wt% based on the total weight of the sliding layer material; and

(8) based on the total weight of the sliding layer material, the content of the reinforcing material is 1-10 wt%, the content of the solid lubricant is 8-30 wt%, and the content of the optional nano-particles is 0.1-10 wt%;

(9) the reinforcing material is selected from one or more of carbon fiber, glass fiber and reinforced polymer; preferably, the reinforcing polymer is selected from one or more of nylon, polyester, aramid fiber, polyimide, polyaryletherketone, polyetheretherketone, polyphenylene oxide, polyphenylene sulfide, polysulfone, polyarylsulfone and polyethersulfone;

(10) the solid lubricant is selected from graphite and MoS₂One or more of graphite fluoride, boron nitride, sodium fluoride, cerium fluoride, lithium fluoride, calcium fluoride, barium sulfate, aluminum oxide, calcium phosphate, calcium sulfate, calcium fluoride, and zinc oxide; and

(11) the nano-particles are selected from one or two of silicon dioxide nano-particles and calcium oxide nano-particles.

3. Metal-reinforced composite material with an elastic layer according to claim 1,

the sliding layer and the sliding layer material filled in the meshes of the metal mesh are formed by laying oily polymer slurry on the surface and meshes of the metal mesh attached to a metal substrate, drying and sintering, the oily polymer slurry comprising a resin composition comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, and an oily solvent; or

The sliding layer and the sliding layer material filled in the meshes of the metal mesh are formed by laminating a composite raw material tape comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles on the surface and meshes of the metal mesh attached to the metal substrate and sintering.

4. A method for preparing the metal-reinforced composite material with an elastic layer according to claim 1 or 2, characterized in that the method comprises the steps of drying and sintering an oily polymer slurry laid on the surface and in the meshes of a metal mesh attached to a metal substrate, the oily polymer slurry comprising a resin composition and an oily solvent, the resin composition comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, the polytetrafluoroethylene being a polytetrafluoroethylene dispersion powder.

5. The method of claim 4, wherein the method has one or more of the following features:

(1) the metal net is connected to the metal substrate through sintering, and the sintering temperature is 800-1000 ℃, preferably 880-920 ℃; preferably, the sintering time is 10-25 minutes; preferably, the sintering is protected by using a mixed gas of an inert gas and a reducing gas, such as a hydrogen-nitrogen mixed gas; in the hydrogen-nitrogen mixed gas, the volume ratio of hydrogen to nitrogen is preferably 5: 1 to 2: 1;

(2) the content of the polytetrafluoroethylene in the resin composition is 60-80 wt% based on the total weight of the resin composition;

(3) based on the total weight of the resin composition, the content of the reinforcing material is 1-10 wt%, the content of the solid lubricant is 8-30 wt%, and the content of the optional nano-particles is 0.1-10 wt%;

(4) the oily solvent is selected from any one or a mixture of any more of kerosene, white oil, naphtha, petroleum-based solvent, naphthenic solvent and aliphatic solvent; preferably, the oily solvent comprises kerosene, white oil, crude gasoline and a petroleum-based solvent, wherein the content of the kerosene is preferably 5-40 wt%, the content of the white oil is preferably 3-20 wt%, the content of the crude gasoline is preferably 20-60 wt%, the content of the petroleum-based solvent is preferably 16-32 wt%, and the petroleum-based solvent is preferably petroleum ether;

(5) the solid content of the oily polymer slurry is 75-85 wt%;

(6) the oily polymer slurry is obtained by mixing a mixture containing polytetrafluoroethylene, a reinforcing material, a solid lubricant and optional nanoparticles with the oily solvent; the mixture is preferably obtained by mixing at-10 to-5 ℃; preferably, before the oily solvent and the mixture are mixed, the mixture is dried, the drying time is preferably 30 minutes to 1 hour, and the drying temperature is preferably 100 to 110 ℃;

(7) drying the oily polymer slurry laid on the meshes and the surface of the metal net at the temperature of 180-250 ℃;

(8) after the oily polymer slurry is laid on the meshes and the surface of the metal net and before drying, the metal net and the metal substrate which are laid with the oily polymer slurry can be integrally cold rolled; and

(9) sintering the composite raw material belt covered and pressed on the meshes and the surface of the metal net at the sintering temperature of 380-400 ℃; the sintering time is preferably 15-30 minutes; preferably, the sintering is protected by a mixed gas of an inert gas and a reducing gas, for example, a mixed atmosphere of hydrogen and nitrogen.

6. A method of preparing a metal reinforced composite material with an elastic layer according to claim 1 or 2, characterized in that it comprises the step of sintering a composite green tape comprising polytetrafluoroethylene, a reinforcing material, a solid lubricant and optionally nanoparticles, said polytetrafluoroethylene being a polytetrafluoroethylene dispersion powder, pressed against the surface and in the meshes of a metal mesh attached to a metal substrate.

7. The method of claim 6, wherein the method has one or more of the following features:

(1) the metal net is connected to the metal substrate through sintering, and the sintering temperature is 800-1000 ℃, preferably 880-920 ℃; preferably, the sintering time is 10-25 minutes; preferably, the sintering is protected by using a mixed gas of an inert gas and a reducing gas, such as a hydrogen-nitrogen mixed gas;

(2) the polytetrafluoroethylene content in the composite raw material tape is 60-80 wt% based on the total weight of the composite raw material tape; and

(3) based on the total weight of the composite raw material tape, the content of the reinforcing material is 1-10 wt%, the content of the solid lubricant is 8-30 wt%, and the content of the optional nano-particles is 0.1-10 wt%;

(4) the composite raw material belt is formed by pressing a mixture containing polytetrafluoroethylene, a reinforcing material, a solid lubricant and optional nano particles into a blank body and then extruding the blank body in a strip form; the mixture is preferably obtained by mixing at-10 to-5 ℃;

(5) the thickness of the composite raw material belt is 0.5-1 mm;

(6) before the composite raw material belt is covered and pressed on the meshes and the surface of the metal net, the composite raw material belt is dried at the preferable temperature of about 100-110 ℃ for 30 minutes-1 hour; and

(7) sintering the composite raw material belt covered and pressed on the meshes and the surface of the metal net at the sintering temperature of 380-400 ℃; the sintering time is preferably 15-30 minutes; preferably, the sintering is protected by a mixed gas of an inert gas and a reducing gas, for example, a mixed atmosphere of hydrogen and nitrogen.

8. A sliding part comprising the metal-reinforced composite material according to any one of claims 1 to 3 or a metal-reinforced composite material produced by the method according to any one of claims 4 to 7; preferably, the sliding component is a bushing, a flanged bearing, a gasket or a backing plate.

9. The polytetrafluoroethylene dispersion powder is applied to preparing metal reinforced composite materials or improving the sliding layer compactness, the sliding layer thickness, the turning performance, the wear resistance, the self-lubricating capacity, the high temperature resistance and/or the corrosion resistance of the metal reinforced composite materials.

10. The application of the composite raw material belt or the oily polymer slurry in preparing a metal reinforced composite material or improving the compactness of a sliding layer, the thickness of the sliding layer, the turning property, the wear resistance, the self-lubricating capacity, the high temperature resistance and/or the corrosion resistance of the metal reinforced composite material, wherein the composite raw material belt or the oily polymer slurry contains polytetrafluoroethylene dispersed powder; preferably, the oily polymer slurry is as defined in claim 4 or 5; preferably, the composite green tape is as claimed in claim 6 or 7.