A copper / steel bimetal self-lubricating slide plate and a preparation method and application thereof

Abstract

The application provides a copper / steel bimetal self-lubricating slide plate and a preparation method and application thereof, and relates to the technical field of composite materials.The copper / steel bimetal self-lubricating slide plate is prepared by sequentially performing nickel plating, copper plating, laying copper alloy bearing layer powder, laying copper alloy lubricating layer powder, pressing, sintering treatment, rolling treatment, aging treatment and preparing a starting lubricating coating on the surface of a steel base plate.The copper / steel bimetal self-lubricating slide plate prepared by the application has the outstanding advantages of high bearing capacity, low friction, high wear resistance, long service life and high temperature resistance.

Description

Technical Field

[0001] This invention relates to the field of composite material technology, specifically to a copper / steel bimetallic self-lubricating slide plate, its preparation method, and its application. Background Technology

[0002] Copper / steel bimetallic self-lubricating slide plates are a typical wear-resistant self-lubricating material component. They are mainly composed of a steel back that bears the load and a copper alloy lubricating layer that reduces friction and wear. Combining the advantages of the steel back and the copper alloy layer, they have both the high load-bearing capacity of the steel back and the friction-reducing and wear-resistant capacity of the alloy layer. As a self-lubricating component, they are widely used in steam turbine support mechanisms, large mold guiding mechanisms, mining and metallurgical equipment guide rails, nuclear power plant support mechanisms, bridge support mechanisms, and other fields.

[0003] Currently, conventional copper / steel bimetallic self-lubricating slide plates are typically manufactured using casting or powder metallurgy techniques. The casting process generally involves casting a layer of copper alloy onto a steel substrate, followed by machining to form the bimetallic self-lubricating slide plate. However, casting inevitably introduces metallurgical defects such as porosity, inclusions, looseness, and cracks into the copper alloy layer, especially at the interface, resulting in low interfacial bonding strength and poor load-bearing capacity. Furthermore, the casting process makes it difficult to introduce a large amount of lubricating components into the copper alloy layer, leading to a high coefficient of friction and poor wear resistance, making it unsuitable for use under extreme conditions such as high temperatures and heavy loads. Powder metallurgy, on the other hand, allows for the introduction of more lubricating components into the copper alloy lubrication layer, mitigating some of the shortcomings of casting and improving both the coefficient of friction and wear resistance. However, due to the presence of numerous micropores and microcracks in the sliding plate lubrication layer prepared by conventional powder metallurgy technology, and the low bonding strength of the copper-steel interface formed by powder metallurgy sintering, the copper alloy lubrication layer is prone to cracking or peeling failure under heavy load and high temperature conditions. This results in poor high temperature load capacity, short service life, and poor reliability, which cannot meet the requirements for use under extreme and harsh conditions such as high temperature and heavy load in the industrial field. Summary of the Invention

[0004] The purpose of this invention is to provide a copper / steel bimetallic self-lubricating slide plate, its preparation method and application. The copper / steel bimetallic self-lubricating slide plate prepared by this invention has outstanding advantages such as high load-bearing capacity, low friction, high wear resistance, long service life and high temperature resistance. It can be applied in heavy-load and high-temperature extreme harsh working conditions in fields such as heavy gas turbines, nuclear energy systems, heavy machinery, molds, bridges, mines, and metallurgy.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] This invention provides a method for preparing a copper / steel bimetallic self-lubricating slide plate, comprising the following steps:

[0007] Nickel is plated on the surface of a steel substrate to obtain a first composite plate; the first composite plate includes a steel substrate and a nickel plating layer attached to the surface of the steel substrate;

[0008] Copper is plated on the surface of the nickel plating layer to obtain a second composite plate; the second composite plate includes a steel substrate and a nickel plating layer and a copper plating layer sequentially attached to the surface of the steel substrate;

[0009] A third composite plate is obtained by sequentially laying copper alloy bearing layer powder and copper alloy lubricating layer powder on the surface of the copper plating layer.

[0010] The third composite plate is subjected to pressing, sintering, rolling and aging treatment in sequence to obtain the fourth composite plate;

[0011] An initial lubricating coating is prepared on the surface of the fourth composite plate to obtain a copper / steel bimetallic self-lubricating slide plate.

[0012] Preferably, the thickness of the nickel plating layer is 10–60 μm.

[0013] Preferably, the thickness of the copper plating layer is 10–60 μm.

[0014] Preferably, the copper alloy support layer powder comprises Cu-Ni-Sn alloy powder; the particle size of the copper alloy support layer powder is 10-120 μm; and the laying thickness of the copper alloy support layer powder is 1-6 mm.

[0015] Preferably, the copper alloy lubricating layer powder includes Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder; the particle size of the copper alloy lubricating layer powder is 10-120 μm; and the laying thickness of the copper alloy lubricating layer powder is 2-15 mm.

[0016] Preferably, the pressing pressure is 1–5 MPa; the pressing time is 2–30 min;

[0017] The sintering temperature is 700–900℃, and the holding time is 30–180 min; the sintering atmosphere is a hydrogen atmosphere.

[0018] The total reduction in the rolling process is 5-15%;

[0019] The aging treatment temperature is 450–500℃, and the aging treatment time is 3–6 hours.

[0020] Preferably, the thickness of the initial lubricating coating is 10–80 μm; the raw materials for preparing the initial lubricating coating include polyimide resin solution, graphite, silver, polytetrafluoroethylene, and molybdenum disulfide.

[0021] The present invention provides a copper / steel bimetallic self-lubricating slide plate prepared by the preparation method described above, comprising a steel substrate, a nickel plating layer, a copper plating layer, a copper alloy bearing layer, a copper alloy lubricating layer, and an initial lubrication coating layer stacked sequentially.

[0022] Preferably, the copper / steel bimetallic self-lubricating slide plate has a bonding strength of 150 MPa or higher, a Brinell hardness of 90 HB or higher, and a coefficient of friction of 0.15 or lower.

[0023] This invention provides the application of the copper / steel bimetallic self-lubricating slide plate described above as a self-lubricating component.

[0024] This invention provides a method for preparing a copper / steel bimetallic self-lubricating slide plate. The method involves sequentially performing nickel plating, copper plating, laying copper alloy bearing layer powder, laying copper alloy lubricating layer powder, pressing, sintering, rolling, aging, and preparing an initial lubricating coating on the surface of a steel substrate to obtain a copper / steel bimetallic self-lubricating slide plate.

[0025] Compared with the prior art, the present invention has the following advantages:

[0026] This invention significantly improves the bonding strength between the copper alloy layer and the steel substrate by preparing a nickel-plated layer and a copper-plated layer as a transition layer between the copper alloy layer and the steel substrate, and by using sintering, rolling and aging treatments. The bonding strength can reach more than 150 MPa. Under extreme harsh conditions such as heavy load and high temperature, the copper alloy lubricating layer will not crack or peel off, thus overcoming the shortcomings of bimetallic sliding plates prepared by existing technologies. It has extremely high load-bearing capacity and safety reliability.

[0027] This invention, through the design of a copper alloy load-bearing layer and the combination of sintering, rolling, and aging processes, produces a copper / steel bimetallic self-lubricating slide plate with a copper alloy layer achieving a Brinell hardness of over 90 HB, thus giving it high load-bearing capacity and maintaining a wear rate of 10% under high temperature and heavy load conditions. -5 mm 3 It has a strength on the order of N·m and exhibits good wear resistance and service life.

[0028] More preferably, the present invention introduces a large amount of solid lubricant such as graphite into the copper alloy lubricating layer and prepares an initial lubricating coating on the copper alloy lubricating layer, so that the coefficient of friction is guaranteed to be below 0.15 at high temperatures from room temperature to 300°C, thus exhibiting good self-lubricating properties. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the structure of the copper / steel bimetallic self-lubricating slide plate prepared according to an embodiment of the present invention;

[0030] Figure 2 This is a micrograph of the cross-section of a copper / steel bimetallic self-lubricating slide plate prepared in Example 1 of the present invention;

[0031] Figure 3 This is a micrograph of the cross-section of a copper / steel bimetallic self-lubricating slide plate prepared in Example 2 of the present invention. Detailed Implementation

[0032] This invention provides a method for preparing a copper / steel bimetallic self-lubricating slide plate, comprising the following steps:

[0033] Nickel is plated on the surface of a steel substrate to obtain a first composite plate; the first composite plate includes a steel substrate and a nickel plating layer attached to the surface of the steel substrate;

[0034] Copper is plated on the surface of the nickel plating layer to obtain a second composite plate; the second composite plate includes a steel substrate and a nickel plating layer and a copper plating layer sequentially attached to the surface of the steel substrate;

[0035] A third composite plate is obtained by sequentially laying copper alloy bearing layer powder and copper alloy lubricating layer powder on the surface of the copper plating layer.

[0036] The third composite plate is subjected to pressing, sintering, rolling and aging treatment in sequence to obtain the fourth composite plate;

[0037] An initial lubricating coating is prepared on the surface of the fourth composite plate to obtain a copper / steel bimetallic self-lubricating slide plate.

[0038] This invention involves nickel plating on the surface of a steel substrate to obtain a first composite plate. In this invention, the steel substrate preferably comprises a stainless steel substrate or a conventional steel substrate. Specifically, the stainless steel substrate preferably comprises commercially available austenitic stainless steel, ferritic stainless steel, martensitic stainless steel, or duplex stainless steel, and more preferably includes 304 stainless steel, 316 stainless steel, 17-4PH stainless steel, or 1Cr13 stainless steel. The conventional steel substrate preferably comprises 20# steel, 45# steel, or 40Cr steel. Using stainless steel as the steel substrate in this invention improves the corrosion resistance and high-temperature resistance of the copper / steel bimetallic self-lubricating sliding plate.

[0039] In this invention, machining of the steel substrate is preferably performed before nickel plating. This machining preferably includes milling and / or grinding. Preferably, the machining process achieves a surface finish of Ra of less than 1.5 μm, more preferably 1.0–1.2 μm. Preferably, cleaning is performed after machining before nickel plating. The cleaning is preferably performed using anhydrous ethanol ultrasonic cleaning. This invention ensures that the steel substrate surface is free of oil and other contaminants, guaranteeing surface cleanliness.

[0040] In this invention, the first composite plate includes a steel substrate and a nickel plating layer attached to the surface of the steel substrate. In this invention, the thickness of the nickel plating layer is preferably 10–60 μm, more preferably 19–45 μm. In this invention, the nickel plating layer is preferably prepared by electroplating. In this invention, the nickel plating layer is a transition layer, the purpose of which is to form a diffusion layer for metallurgical bonding between the copper alloy layer and the steel substrate, thereby improving the interfacial bonding strength between the copper alloy layer and the steel substrate.

[0041] After obtaining the first composite plate, the present invention further plates copper onto the surface of the nickel plating layer to obtain a second composite plate. In this invention, the second composite plate comprises a steel substrate and a nickel plating layer and a copper plating layer sequentially attached to the surface of the steel substrate. In this invention, the thickness of the copper plating layer is preferably 10–60 μm, more preferably 20–51 μm. In this invention, the copper plating layer is preferably prepared by electroplating. In this invention, the copper plating layer also serves as a transition layer, forming a copper-nickel diffusion layer between the copper plating layer and the nickel plating layer, further enhancing the bonding strength between the copper alloy layer and the steel substrate.

[0042] After obtaining the second composite plate, the present invention sequentially lays copper alloy bearing layer powder and copper alloy lubricating layer powder on the surface of the copper-plated layer to obtain a third composite plate. In the present invention, the copper alloy bearing layer powder preferably comprises Cu-Ni-Sn alloy powder. In the present invention, the composition of the Cu-Ni-Sn alloy powder, by mass percentage, is: Ni 10-20%, Sn 6-12%, with the balance being Cu; more preferably, Ni 14-17%, Sn 8-10%, with the balance being Cu. In the present invention, the particle size of the copper alloy bearing layer powder is preferably 10-120 μm, more preferably 10-50 μm; the laying thickness of the copper alloy bearing layer powder is preferably 1-6 mm, more preferably 2-5 mm. In the present invention, the purpose of laying the copper alloy bearing layer powder is, on the one hand, to improve the load-bearing capacity, and on the other hand, to further improve the bonding strength between the steel substrate and the copper alloy layer, making it less prone to cracking and peeling failures during friction.

[0043] In this invention, the copper alloy lubricating layer powder preferably comprises Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder; the preparation method of the copper alloy lubricating layer powder preferably comprises: mixing Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder to obtain the copper alloy lubricating layer powder. In this invention, the mass percentage of Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder is (75-90)%:(2-10)%:(2-4)%:(2-4)%:(3-5)%:(3-5)%, more preferably 75-86%:4-9%:2-3%:2-3%:3-5%:3-5%. In this invention, the composition of the Cu-Ni-Sn-Pb alloy powder, by mass percentage, is: Ni 14-22%, Sn 8-15%, Pb 4-10%, with the balance being Cu; more preferably, Ni 17-20%, Sn 10-11%, Pb 7-8%, with the balance being Cu. In this invention, the particle size of the copper alloy lubricating layer powder is preferably 10-120 μm, more preferably 10-50 μm; the thickness of the copper alloy lubricating layer powder is preferably 2-15 mm, more preferably 3-10 mm. In this invention, the copper alloy lubricating layer mainly functions to reduce the coefficient of friction and improve wear resistance, serving as the functional layer of the copper / steel bimetallic self-lubricating sliding plate. In this invention, the copper alloy lubricating layer powder must be laid with uniform thickness and a smooth surface, without obvious agglomeration, depressions, pores, or unevenness.

[0044] After obtaining the third composite plate, the present invention sequentially performs pressing, sintering, rolling and aging treatments on the third composite plate to obtain the fourth composite plate.

[0045] In this invention, the pressing pressure is preferably 1-5 MPa, more preferably 1.5-3 MPa; the pressing time is preferably 2-30 min, more preferably 3-20 min. In this invention, the pressing temperature is room temperature. In this invention, the pressing is preferably cold pressing. In this invention, the pressing is preferably performed in a mold. This invention compacts the copper alloy bearing layer powder and the copper alloy lubricating layer powder through pressing, giving them a certain strength.

[0046] In this invention, the sintering temperature is preferably 700–900°C, more preferably 750–880°C; the holding time is preferably 30–180 min, more preferably 120–150 min; and the sintering atmosphere is preferably a hydrogen atmosphere. In this invention, the heating rate from room temperature to the sintering temperature is preferably 3–15°C / min, more preferably 5–10°C / min.

[0047] Preferably, after the sintering process, the sample is cooled to room temperature in the furnace. This invention uses a sintering process to diffuse copper alloy carrier layer powder and copper alloy lubricating layer powder particles at high temperature to form sintering necks, which are then sintered onto a steel substrate to form a metallurgical bond.

[0048] In this invention, the total reduction in the rolling process is preferably 5-15%, more preferably 7-10%. In this invention, the rolling process is preferably a one-time rolling or multiple rolling processes.

[0049] In this invention, the aging treatment temperature is preferably 450–500°C, more preferably 450–480°C; the aging treatment time is preferably 3–6 hours, more preferably 4–5 hours. In this invention, the aging treatment is preferably carried out in an atmospheric environment within a box furnace. In this invention, the aging treatment serves two purposes: firstly, to release the stress after rolling, and secondly, to further improve the strength and hardness of the lubricating layer.

[0050] Preferably, after the aging treatment, the furnace is cooled to room temperature.

[0051] Preferably, the present invention further includes surface machining after the aging treatment. In this invention, the surface machining preferably includes milling and / or grinding. The present invention achieves an average surface finish of Ra less than 1.5 μm, more preferably 1.2 μm, through surface machining. The present invention enables the sheet material to achieve the required dimensions and surface finish through surface machining.

[0052] After obtaining the fourth composite plate, the present invention prepares an initial lubricating coating on the surface of the fourth composite plate to obtain a copper / steel bimetallic self-lubricating slide plate. In the present invention, the thickness of the initial lubricating coating is preferably 10–80 μm, more preferably 15–70 μm. In the present invention, the raw materials for preparing the initial lubricating coating preferably include a polyimide resin solution, graphite, silver, polytetrafluoroethylene (PTFE), and molybdenum disulfide. In the present invention, the mass percentage of the polyimide resin solution, graphite, silver, PTFE, and molybdenum disulfide is preferably (35–45)%:(12–17)%:(8–12)%:(22–27)%:(8–12)%, more preferably 40%:15%:10%:25%:10%. In the present invention, the solid content of the polyimide resin solution is preferably 40–80%, more preferably 50–60%.

[0053] In this invention, the preferred method for preparing the initial lubricating coating includes: mixing a polyimide resin solution, graphite, silver, polytetrafluoroethylene, and molybdenum disulfide to obtain a slurry; coating the slurry onto the surface of the fourth composite plate, and curing it to obtain a copper / steel bimetallic self-lubricating sliding plate. In this invention, the solid content of the slurry is preferably 20-45%. In this invention, the coating is preferably applied by spraying. In this invention, the curing temperature is preferably 120-180°C, more preferably 150-160°C; the curing time is preferably 1-2 hours.

[0054] The present invention provides a copper / steel bimetallic self-lubricating slide plate prepared by the preparation method described above, comprising a steel substrate, a nickel plating layer, a copper plating layer, a copper alloy bearing layer, a copper alloy lubricating layer, and an initial lubrication coating layer stacked sequentially.

[0055] In this invention, the bonding strength of the copper / steel bimetallic self-lubricating slide plate is preferably above 150 MPa, the Brinell hardness is preferably above 90 HB, and the coefficient of friction is preferably below 0.15.

[0056] The present invention provides the application of the copper / steel bimetallic self-lubricating slide plate described in the above technical solution as a self-lubricating component, preferably applied in steam turbine support mechanisms, large mold guiding mechanisms, mining and metallurgical equipment guide rails, nuclear power plant support mechanisms or bridge support mechanisms.

[0057] The technical solutions of this invention will be clearly and completely described below with reference to the embodiments thereof. Obviously, the described embodiments are only a part of the embodiments of this invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0058] Example 1

[0059] (1) Preparation of stainless steel substrate: 316 stainless steel substrate is selected. The stainless steel is processed into a plate of 200mm×300mm×10mm. On the side where the lubricating layer is prepared, the surface finish is processed to Ra of 1.2μm by grinding. The surface is ultrasonically cleaned with anhydrous ethanol to ensure that there is no oil on the surface.

[0060] (2) Preparation of nickel plating layer: A nickel plating layer is plated on a stainless steel substrate using electroplating technology. The average thickness of the nickel plating layer is 19 μm. After plating, the surface is cleaned.

[0061] (3) Preparation of copper plating layer: After nickel plating is completed, pure copper plating layer is plated on the nickel plating layer using electroplating technology. The average thickness of the copper plating layer is 20μm. After plating is completed, the surface is cleaned.

[0062] (4) Laying copper alloy carrier layer powder: Laying copper alloy carrier layer powder on top of copper plating layer. The powder composition is Cu-Ni-Sn alloy, the particle size of the powder is 10~120μm, and the laying thickness is 2mm. The mass percentage of Cu-Ni-Sn alloy composition of copper alloy carrier layer is: Ni 17%, Sn 10%, and the balance is Cu.

[0063] (5) Laying a copper alloy lubricating layer powder: A copper alloy lubricating layer powder is then laid on top of the copper alloy carrier layer powder. This copper alloy lubricating layer powder is composed of Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder in a mass percentage ratio of 86%:4%:2%:2%:3%:3%. The particle size of this powder is 10-120μm, and the laying thickness is 3mm. The mass percentage content of the Cu-Ni-Sn-Pb alloy powder is: Ni 17%, Sn 11%, Pb 7%, with the balance being Cu. During preparation, Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder and WS2 powder are measured in proportion and then mixed in a three-dimensional mixer for 6 hours to ensure uniformity. The uniformly mixed copper alloy lubricating layer powder is then evenly spread on the copper alloy bearing layer powder, ensuring that the surface is flat and free of defects during the spreading process.

[0064] (6) Copper alloy layer pressing: After the copper alloy bearing layer powder and copper alloy lubricating layer powder are laid, they are loaded into the mold and cold-pressed on the hydraulic press. The pressing pressure is 1.5MPa and the pressing time is 3min.

[0065] (7) Sintering treatment: The sample after pressing is sintered in a hydrogen atmosphere furnace. The sintering temperature is 700℃, the heating rate from room temperature to the sintering temperature is 3℃ / min, the holding time at 700℃ is 180min, and the sample is cooled to room temperature with the furnace after sintering.

[0066] (8) Rolling process: The bimetallic self-lubricating slide blank after sintering is rolled in one pass with a rolling pressure of 7%.

[0067] (9) Aging treatment: After rolling, the material is aged. The aging treatment is carried out in an atmospheric environment in a box furnace. The aging temperature is 450℃ and the aging time is 6h. After aging, the material is cooled to room temperature in the furnace.

[0068] (10) Surface machining: After aging, the surface is milled and ground to achieve an average surface finish of Ra of 1.2μm.

[0069] (11) Preparation of the initial lubricating coating: After surface machining, an initial lubricating coating is prepared by spraying onto the surface of the copper alloy lubricating layer. The raw materials for the initial lubricating coating are polyimide resin solution (solid content of 50%), graphite, silver, polytetrafluoroethylene, and molybdenum disulfide, with a mass percentage of 40%:15%:10%:25%:10%. The raw materials are first mixed into a slurry, and then sprayed onto the surface of the copper alloy lubricating layer. The coating thickness is controlled between 15 and 25 μm, and finally cured at 150°C for 2 hours to obtain a copper / steel bimetallic self-lubricating sliding plate. Figure 1 As shown, the copper / steel bimetallic self-lubricating slide plate prepared in this embodiment consists of a stainless steel substrate, a nickel plating layer, a copper plating layer, a copper alloy bearing layer, a copper alloy lubrication layer, and an initial lubrication coating layer stacked sequentially.

[0070] Typical micrographs of the cross-sectional microstructure of this copper / steel bimetallic self-lubricating slide are shown below. Figure 2 As shown, the stainless steel substrate layer, nickel plating layer, copper plating layer, copper alloy carrier layer, copper alloy lubrication layer, and initial lubrication coating can be clearly observed.

[0071] The hardness of the copper alloy layer of the copper / steel bimetallic self-lubricating slide plate was tested according to the method given in GB / T 231.1-2018 (Britton hardness test for metallic materials). The interfacial bonding strength of the copper / steel bimetallic self-lubricating slide plate was tested according to the method given in YS / T 485-2005 (Determination of shear strength of sintered bimetallic materials). The coefficient of friction and wear amount of the copper / steel bimetallic self-lubricating slide plate were tested according to the method given in GB / T 12444-2006 (Test method for wear of metallic materials: ring-block sliding wear test). The test results of hardness, bonding strength, coefficient of friction at room temperature and 300℃, and wear amount of the copper / steel bimetallic self-lubricating slide plate prepared in this embodiment are shown in Table 1.

[0072] Table 1. Mechanical and tribological properties of the copper / steel bimetallic self-lubricating slide plate prepared in Example 1.

[0073] Brinell hardness / HB 92 Bond strength / MPa 166 Average coefficient of friction at room temperature 0.09 <![CDATA[Average wear rate at room temperature / mm 3 / (N·m)]]> <![CDATA[6.5×10 -5 ]]> Average coefficient of friction at 300℃ 0.14 <![CDATA[Average wear rate at 300°C / mm 3 / (N·m)]]> <![CDATA[7.7×10 -5 ]]>

[0074] As shown in Table 1, the copper / steel bimetallic self-lubricating slide plate prepared by the present invention has good load-bearing capacity and tribological properties, and excellent overall performance.

[0075] Example 2

[0076] (1) Preparation of stainless steel substrate: 1Cr13 stainless steel substrate is selected. The stainless steel is processed into a plate of 400mm×150mm×15mm. On the side where the lubricating layer is prepared, the surface finish is processed to Ra of 1.0μm by grinding. The surface is ultrasonically cleaned with anhydrous ethanol to ensure that there is no oil on the surface.

[0077] (2) Preparation of nickel plating layer: A nickel plating layer is plated on a stainless steel substrate using electroplating technology. The average thickness of the nickel plating layer is 45μm. After plating, the surface is cleaned.

[0078] (3) Preparation of copper plating layer: After nickel plating is completed, pure copper plating layer is plated on the nickel plating layer using electroplating technology. The average thickness of the copper plating layer is 51μm. After plating is completed, the surface is cleaned.

[0079] (4) Laying copper alloy carrier layer powder: Laying copper alloy carrier layer powder on top of copper plating layer. The powder composition is Cu-Ni-Sn alloy, the particle size of the powder is 10~120μm, and the laying thickness is 5mm. The mass percentage of Cu-Ni-Sn alloy composition of copper alloy carrier layer is: Ni 14%, Sn 8%, and the balance is Cu.

[0080] (5) Laying copper alloy lubricating powder: A layer of copper alloy lubricating powder is then laid on top of the copper alloy carrier layer powder. This copper alloy lubricating powder is composed of Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder in a mass percentage ratio of 75%:9%:3%:3%:5%:5%. The particle size of this powder is 10-120μm, and the laying thickness is 10mm. The mass percentage composition of the Cu-Ni-Sn-Pb alloy powder is: Ni 20%, Sn 10%, Pb 8%, with the balance being Cu. During preparation, Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder and WS2 powder are measured in proportion and then mixed in a three-dimensional mixer for 6 hours to ensure uniformity. The uniformly mixed copper alloy lubricating layer powder is then evenly spread on the copper alloy bearing layer powder, ensuring that the surface is flat and free of defects during the spreading process.

[0081] (6) Copper alloy layer pressing: After the copper alloy bearing layer powder and copper alloy lubricating layer powder are laid, they are loaded into the mold and cold-pressed on the hydraulic press. The pressing pressure is 3MPa and the pressing time is 20min.

[0082] (7) Sintering treatment: The sample after pressing is sintered in a hydrogen atmosphere furnace. The sintering temperature is 880°C. The heating rate from room temperature to the sintering temperature is 10°C / min. The holding time at 880°C is 30min. After sintering, the sample is cooled to room temperature in the furnace.

[0083] (8) Rolling process: The bimetallic self-lubricating slide blank after sintering is rolled in one pass with a rolling pressure of 10%.

[0084] (9) Aging treatment: After rolling, the material is aged. The aging treatment is carried out in an atmospheric environment in a box furnace. The aging temperature is 500℃ and the aging time is 3h. After aging, the material is cooled to room temperature in the furnace.

[0085] (10) Surface machining: After aging, the surface is milled and ground to achieve an average surface finish of Ra of 1.2μm.

[0086] (11) Preparation of the initial lubricating coating: After surface machining, an initial lubricating coating is prepared by spraying onto the surface of the copper alloy lubricating layer. The raw materials for the initial lubricating coating are polyimide resin solution (solid content of 50%), graphite, silver, polytetrafluoroethylene, and molybdenum disulfide, with a mass percentage of 40%:15%:10%:25%:10%. The raw materials are first mixed into a slurry, and then sprayed onto the surface of the copper alloy lubricating layer. The coating thickness is controlled between 60 and 70 μm, and finally cured at 180°C for 1 hour to obtain a copper / steel bimetallic self-lubricating sliding plate. Figure 1 As shown, the copper / steel bimetallic self-lubricating slide plate prepared in this embodiment consists of a stainless steel substrate, a nickel plating layer, a copper plating layer, a copper alloy bearing layer, a copper alloy lubrication layer, and an initial lubrication coating layer stacked sequentially.

[0087] Typical micrographs of the cross-sectional microstructure of this copper / steel bimetallic self-lubricating slide are shown below. Figure 3 As shown, the stainless steel substrate layer, nickel plating layer, copper plating layer, copper alloy carrier layer, copper alloy lubrication layer, and initial lubrication coating can be clearly observed.

[0088] Similar to Example 1, the hardness of the copper alloy layer of the copper / steel bimetallic self-lubricating slide plate was tested according to the method given in GB / T 231.1-2018 (Britton hardness test for metallic materials), the interfacial bonding strength of the copper / steel bimetallic self-lubricating slide plate was tested according to the method given in YS / T485-2005 (Determination of shear strength of sintered bimetallic materials), and the coefficient of friction and wear amount of the copper / steel bimetallic self-lubricating slide plate were tested according to the method given in GB / T12444-2006 (Test method for wear of metallic materials: ring-block sliding wear test). The test results of hardness, bonding strength, coefficient of friction at room temperature and 300°C, and wear amount of the copper / steel bimetallic self-lubricating slide plate prepared in this example are shown in Table 2.

[0089] Table 2. Mechanical and tribological properties of the copper / steel bimetallic self-lubricating slide plate prepared in Example 2.

[0090]

[0091]

[0092] As shown in Table 2, the copper alloy layer of the copper / steel bimetallic self-lubricating slide prepared by the present invention has excellent properties such as high hardness, high bonding strength, good load-bearing capacity, low friction at room temperature and 300°C, and high wear resistance.

[0093] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a copper / steel bimetallic self-lubricating slide plate, comprising the following steps: Nickel is plated on the surface of a steel substrate to obtain a first composite plate; the first composite plate includes a steel substrate and a nickel plating layer attached to the surface of the steel substrate; Copper is plated on the surface of the nickel plating layer to obtain a second composite plate; the second composite plate includes a steel substrate and a nickel plating layer and a copper plating layer sequentially attached to the surface of the steel substrate; A third composite plate is obtained by sequentially laying copper alloy bearing layer powder and copper alloy lubricating layer powder on the surface of the copper plating layer. The third composite plate is subjected to pressing, sintering, rolling and aging treatment in sequence to obtain the fourth composite plate; An initial lubrication coating is prepared on the surface of the fourth composite plate to obtain a copper / steel bimetallic self-lubricating slide plate. The copper alloy support layer powder includes Cu-Ni-Sn alloy powder; the particle size of the copper alloy support layer powder is 10~120μm; and the laying thickness of the copper alloy support layer powder is 1~6mm. The copper alloy lubricating layer powder includes Cu-Ni-Sn-Pb alloy powder, graphite powder, BaF2 powder, CaF2 powder, CeO2 powder, and WS2 powder; the particle size of the copper alloy lubricating layer powder is 10~120μm; and the thickness of the copper alloy lubricating layer powder is 2~15mm.

2. The preparation method according to claim 1, characterized in that, The thickness of the nickel plating layer is 10~60μm.

3. The preparation method according to claim 1, characterized in that, The thickness of the copper plating layer is 10~60μm.

4. The preparation method according to claim 1, characterized in that, The pressing pressure is 1~5MPa; the pressing time is 2~30min; The sintering temperature is 700~900℃, and the holding time is 30~180min; the sintering atmosphere is hydrogen atmosphere; the total reduction in the rolling process is 5~15%; The aging treatment temperature is 450~500℃, and the aging treatment time is 3~6h.

5. The preparation method according to claim 1, characterized in that, The thickness of the initial lubricating coating is 10~80μm; the raw materials for preparing the initial lubricating coating include polyimide resin solution, graphite, silver, polytetrafluoroethylene and molybdenum disulfide.

6. The copper / steel bimetallic self-lubricating slide plate prepared by the preparation method according to any one of claims 1 to 5 comprises a steel substrate, a nickel plating layer, a copper plating layer, a copper alloy bearing layer, a copper alloy lubricating layer, and an initial lubricating coating, which are stacked sequentially.

7. The copper / steel bimetallic self-lubricating slide plate according to claim 6, characterized in that, The copper / steel bimetallic self-lubricating sliding plate has a bonding strength of over 150 MPa, a Brinell hardness of over 90 HB, and a coefficient of friction of less than 0.

15.

8. The application of the copper / steel bimetallic self-lubricating slide plate according to any one of claims 6 to 7 as a self-lubricating component.

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