CN111360244B

CN111360244B - Bearing alloy blank, bearing alloy, bearing material, and preparation method and application thereof

Info

Publication number: CN111360244B
Application number: CN201811593865.8A
Authority: CN
Inventors: 陈进添; 杨琪
Original assignee: SHANGHAI HEWEI INDUSTRIAL CO LTD
Current assignee: SHANGHAI HEWEI INDUSTRIAL CO LTD
Priority date: 2018-12-25
Filing date: 2018-12-25
Publication date: 2022-06-07
Anticipated expiration: 2038-12-25
Also published as: CN111360244A

Abstract

The invention discloses a bearing alloy blank, a bearing alloy, a bearing material, a preparation method and application thereof. The preparation method of the bearing alloy blank comprises the following steps: in the mixed solution, after nickel nitrate coated films are respectively formed on the surfaces of graphite powder and nickel-aluminum bronze powder, reducing the nickel nitrate coated films into nickel coated films in a reducing atmosphere; the nickel-aluminum bronze powder is nickel-aluminum bronze powder with an oxidation film removed; the mixed solution is an aqueous solution containing nickel nitrate and polyvinyl alcohol, and the average molecular weight of the polyvinyl alcohol is in the range of 16000-130000; the reducing atmosphere is an atmosphere containing hydrogen. The preparation method has the advantages of simpler process, higher yield, lower production cost and easier realization of industrial production. In the bearing alloy and the bearing material, the interface bonding strength between the graphite powder and the nickel-aluminum bronze powder is high, and the antifriction property, the wear resistance and the corrosion resistance are good.

Description

Bearing alloy blank, bearing alloy, bearing material, and preparation method and application thereof

Technical Field

The invention relates to a bearing alloy blank, a bearing alloy, a bearing material, a preparation method and application thereof.

Background

A plain bearing refers to a bearing that operates under sliding friction. The material from which the sliding bearing is made must have the characteristics of a low coefficient of friction, adequate fatigue strength, good running-in properties and good corrosion resistance. The bearing alloy of the conventional sliding bearing material is a composite material consisting of a soft phase material and a hard phase material, such as babbitt metal, copper alloy, aluminum alloy, gray cast iron, wear-resistant cast iron and the like. Wherein copper alloy sliding bearing materials are commonly used as sliding bearing materials for heavy-duty engines.

The marine engine usually works in an environment with high salt content, the power of the marine engine is very high, and the bearing bush material matched with the marine engine is required to have the characteristics of high bearing capacity, good corrosion resistance and the like. The nickel-aluminum bronze contains alloy elements such as copper, aluminum, tin, nickel and the like, has high strength and good wear resistance and corrosion resistance, but the nickel-aluminum bronze has high friction coefficient and lacks soft phase inside, so that the nickel-aluminum bronze is difficult to be directly used as a material for manufacturing a bearing bush of a marine engine.

At present, lead bronze is generally adopted as a sliding bearing material for heavy-duty engines. However, lead is a heavy metal with high toxicity, and the lead-containing sliding bearing material pollutes the environment during processing and use, so that various countries in the world have laws and regulations for limiting the use of the lead-containing sliding bearing material.

At present, no patent documents of sliding bearing materials exclusively for marine engines are disclosed, and the patent documents of sliding bearing materials which have been disclosed as useful as marine engines are listed below.

Specifically, patent documents that can be used as a lead bronze sliding bearing material for a marine engine are as follows: chinese patent document "composite sliding bearing material and its preparation method" (application number: 200510120729.3) discloses a composite sliding bearing material, which comprises ordinary babbitt metal and carbon nano-tubes, wherein the ordinary babbitt metal is used as matrix, and the carbon nano-tubes are used as reinforcement. In this patent document, the sliding bearing material used is a lead-containing composite sliding bearing material, and there is a problem of environmental pollution.

The patents of the lead-free copper alloy sliding bearing material which can be used as the marine engine are as follows: the chinese patent document "plain bearing composite" (application No. 201380063861.8) discloses a metallic plain bearing material comprising a bearing layer, in particular a steel bearing layer, a copper base layer containing tin or aluminium or nickel or zinc or a combination thereof, a friction layer comprising a spray coating directed towards the sliding partner, in particular an aluminium-based friction layer. Chinese patent document "a high-strength antifriction lead-free copper-based sliding bearing material" (application No. 201810216398.0) discloses a high-strength antifriction lead-free copper-based sliding bearing material which is composed of the following raw materials: 70-98 wt% of bronze powder, 1-15 wt% of copper sulfide powder and 1-15 wt% of iron powder. The chinese patent document "a copper alloy material for a sliding bearing" (application No. 201310349937.5) discloses a copper alloy material for a sliding bearing, which is composed of the following raw materials: 2.4 to 2.8 weight percent of nickel, 0.8 to 1.2 weight percent of silicon, 2 to 2.5 weight percent of manganese, less than 0.2 weight percent of iron, less than 0.1 weight percent of tin, 0.3 to 0.7 weight percent of cobalt, 1.2 to 1.6 weight percent of aluminum, 55 to 59 weight percent of copper and the balance of zinc. The Chinese patent document 'an automobile sliding bearing made of a novel material' (application number: 201310563035.1) discloses an automobile sliding bearing made of a novel material, which is a three-layer composite material taking polytetrafluoroethylene as a surface layer and porous bronze and a steel plate as an inner layer. Chinese patent document "manufacturing process of phosphor bronze-steel bimetallic bearing material with phosphor content more than 0.1%" (application number: 200510110718.7) discloses a phosphor bronze lead-free copper alloy sliding bearing material and a preparation method thereof. Chinese patent document "Nickel bronze-steel composite bimetallic bearing material and manufacturing method thereof" (application number: 200810039660.5) discloses a nickel bronze lead-free copper alloy sliding bearing material and a preparation method thereof. Chinese patent document "bismuth bronze-steel composite bimetallic bearing material and manufacturing method thereof" (application number: 200910044854.9) discloses a bismuth bronze lead-free copper alloy sliding bearing material and a preparation method thereof. None of the above patent documents mentions the use of nickel-aluminum bronze as a composite sliding bearing material.

In the prior art, relevant documents report that graphite is used as a lubricant for a lubricating component of a sliding bearing material, and the specific details are as follows: chinese patent document CN201711282913.7 discloses a copper-based alloy sliding bearing material and a preparation method thereof, wherein the copper-based alloy sliding bearing material is composed of the following raw materials: 1.2 to 1.4 weight percent of tin, 8.2 to 8.5 weight percent of nickel, 91.2 to 91.5 weight percent of copper, 0.4 to 0.5 weight percent of silicon powder, 1.1 to 1.3 weight percent of graphite powder, 1.3 to 1.4 weight percent of iron powder, 2 to 3 weight percent of zinc stearate, 2.2 to 2.4 weight percent of aluminum powder, 0.2 to 0.4 weight percent of boron nitride, 0.2 to 0.5 weight percent of bismuth and 1 to 2 weight percent of assistant. Chinese patent document CN201210459742.1 discloses a sliding bearing material, wherein the sliding bearing material includes a metal base layer and a lubricating layer, the lubricating layer and the metal base layer are directly bonded together, wherein the metal base layer is one of stainless steel, low carbon steel and metal alloy, and the lubricating layer is a mixture of polytetrafluoroethylene, graphite and copper powder. In none of the above patent documents, the use of nickel-aluminum bronze as a composite sliding bearing material is mentioned.

At present, in the prior art, a casting method is adopted to prepare the nickel-aluminum bronze sliding bearing material, however, a method for preparing the nickel-aluminum bronze sliding bearing material by taking nickel-aluminum bronze powder as a raw material is not available.

Disclosure of Invention

The invention aims to overcome the defect that no method for preparing a nickel-aluminum bronze sliding bearing material by taking nickel-aluminum bronze powder as a raw material exists in industrial production in the prior art, and provides a novel bearing alloy blank, a novel bearing alloy, a novel bearing material, and a preparation method and application thereof.

The preparation method of the bearing alloy and the bearing material takes the nickel-aluminum bronze powder as the raw material, has simpler process, higher yield and lower production cost, and is easier to realize industrial production. In the bearing alloy and the bearing material prepared by the preparation method, the graphite powder and the nickel-aluminum bronze powder are in a uniform mixing state, the interface bonding strength between the graphite powder and the nickel-aluminum bronze powder is high, the friction reduction performance and the wear resistance performance are good, and the corrosion resistance performance is good.

Here, the inventors wish to explain that the inventors have studied in the field of nickel-aluminum bronzes for over a decade. At the beginning of research, the inventor finds that the nickel-aluminum bronze powder cannot be sintered, and then, after years of research, the inventor finds that a layer of dense oxide film on the surface of the nickel-aluminum bronze powder is a cause of the sintering failure, and the removal of the oxide film on the surface of the nickel-aluminum bronze powder can be realized only by removing the oxide film by acid washing, so that the problem of the sintering failure of the nickel-aluminum bronze powder can be solved. However, the antifriction properties of the above-mentioned nickel-aluminum bronze powder are not very good, and the inventors of the present invention have found that the addition of graphite powder can improve the antifriction properties of the nickel-aluminum bronze powder by adding graphite powder thereto, but the addition of graphite powder has the following problems: graphite powder and nickel aluminium bronze powder are incompatible, can't realize graphite powder and nickel aluminium bronze powder's misce bene at all through mechanical mixing, and in sintering process afterwards, both can't realize better sintering at all, and can form the large granule of the complete cladding graphite powder of copper or the large granule of the incomplete cladding graphite powder of copper, seriously influence the wearability of gained nickel aluminium bronze powder. Then, the inventor tried many methods of uniformly mixing the graphite powder and the nickel-aluminum bronze powder by mechanical mixing, but the results are not ideal, and finally, the inventor tried to treat the graphite powder and the nickel-aluminum bronze powder with the oxidation film removed by using a mixed solution (an aqueous solution containing nickel nitrate and polyvinyl alcohol), and found that the graphite powder and the nickel-aluminum bronze powder can be uniformly mixed by coating a layer of metallic nickel on the surfaces of the graphite powder and the nickel-aluminum bronze powder, and the interface bonding strength between the graphite powder and the nickel-aluminum bronze powder in the obtained bearing alloy can be greatly improved, so that the wear resistance and the friction reduction performance of the bearing alloy are improved, and meanwhile, the better corrosion resistance is also obtained. The bearing material having the obtained bearing alloy also has the above-described excellent properties.

The invention solves the technical problems through the following technical scheme:

the invention provides a preparation method of a bearing alloy blank, which comprises the following steps:

in the mixed solution, after nickel nitrate coated films are respectively formed on the surfaces of graphite powder and nickel-aluminum bronze powder, reducing the nickel nitrate coated films into nickel coated films in a reducing atmosphere; the nickel-aluminum bronze powder is nickel-aluminum bronze powder with an oxidation film removed; the mixed solution is an aqueous solution containing nickel nitrate and polyvinyl alcohol, and the average molecular weight of the polyvinyl alcohol is in the range of 16000-130000; the reducing atmosphere is an atmosphere containing hydrogen.

In the preparation method, the graphite powder can be conventional graphite powder in the prior art. The average particle diameter of the graphite powder is preferably 30 to 50 μm.

In the preparation method, the nickel-aluminum bronze powder can be produced by a conventional aerial fog method or a water fog method.

The chemical composition of the nickel-aluminum bronze powder is generally as follows: c is more than 0 and less than or equal to 0.1 wt%, Si is more than 0 and less than or equal to 0.15 wt%, Mn: 0.8-2.5 wt%, Pb more than 0 and less than or equal to 0.02 wt%, Fe: 4-5 wt%, Al: 8.5-10 wt%, Ni: 4-5 wt% and Cu for the rest.

Wherein the average particle size of the nickel-aluminum bronze powder is preferably 50 to 200 μm.

Wherein the nickel-aluminum bronze powder with the oxide film removed can be obtained by the following method: treating with 5 wt% dilute hydrochloric acid, and cleaning with pure water for 3-5 times.

In the above production method, the ratio of the mass of the graphite powder to the mass of the nickel-aluminum bronze powder is preferably 2 to 5:98 to 95, more preferably 2 to 4:98 to 94, still more preferably 2.95 to 3.05:97.05 to 96.85, and may be, for example, 3: 97.

In the above preparation method, the mass fraction of nickel nitrate in the mixed solution is preferably 20% to 50%, more preferably 35% to 40%.

In the above preparation method, the mass fraction of the polyvinyl alcohol in the mixed solution is preferably 5% to 10%, more preferably 7% to 8%.

In the above preparation method, the product type of the polyvinyl alcohol is preferably polyvinyl alcohol 1788. The polyvinyl alcohol preferably has an average molecular weight of 74800. The polyvinyl alcohol may be, for example, polyvinyl alcohol 1788, a product model of conifer chemical ltd, guangzhou, and having an average molecular weight of 74800.

In the above production method, the mass ratio of the mixed solution to the nickel-aluminum bronze powder is preferably 1:4 to 8, more preferably 1: 6.

In the above preparation method, the mixing time is preferably 3 to 6 hours. The mixing can be carried out, for example, in a blender.

In the above preparation method, the drying is preferably performed before the reduction. The temperature of the drying is preferably 100-.

In the above preparation method, the reducing atmosphere is a hydrogen atmosphere, or the reducing atmosphere is a mixed atmosphere of hydrogen and nitrogen.

In the above preparation method, the temperature of the reduction is preferably 400-600 ℃. The time for the reduction is preferably 30 to 180 minutes.

In the above production method, the reduction is preferably followed by a crushing treatment. The grinding process can be carried out, for example, in a roller mill.

In the preparation method, the mass fraction of the graphite powder in the bearing alloy blank is preferably 2-4%.

In a preferred embodiment of the above preparation method, the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 2.95-3.05:97.05-96.85, the mass fraction of the nickel nitrate in the mixed solution is 35-40%, the mass fraction of the polyvinyl alcohol in the mixed solution is 7-8%, the mass ratio of the mixed solution to the nickel-aluminum bronze powder is 1:6-8, the reduction temperature is 400-600 ℃, and the reduction time is 30-180 minutes.

In a preferred embodiment of the above preparation method, the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 2.95-3.05:97.05-96.85, the mass fraction of nickel nitrate in the mixed solution is 35%, the mass fraction of polyvinyl alcohol in the mixed solution is 7%, the mass ratio of the mixed solution to the nickel-aluminum bronze powder is 1:6, the reduction temperature is 400 ℃, and the reduction time is 180 minutes.

The invention also provides a bearing alloy blank prepared by the preparation method of the bearing alloy blank.

The invention also provides a bearing alloy, and the bearing alloy is prepared from the bearing alloy blank. The bearing alloy is made by powder metallurgy methods conventional in the art.

The invention also provides a bearing material which is of a laminated structure and comprises the bearing alloy and a substrate, wherein the bearing alloy is attached to the substrate.

In the above bearing material, the thickness of the bearing alloy may be a thickness conventional in the art, preferably 0.5 to 2mm, more preferably 0.5 to 1.5 mm.

In the above bearing material, the substrate may be, for example, a low carbon steel plate substrate conventional in the art, and the chemical composition of the low carbon steel plate substrate is generally as follows: c is more than 0 and less than or equal to 0.03 wt%, Si is more than 0 and less than or equal to 0.05 wt%, Mn is more than 0 and less than or equal to 0.5 wt%, P is more than 0 and less than or equal to 0.035 wt%, S is more than 0 and less than or equal to 0.025 wt%, and the balance is Fe.

Wherein the roughness of the contact surface of the low carbon steel plate substrate and the bearing alloy is preferably Ra 25. The roughness may be achieved by methods conventional in the art, such as by sanding the contact surface with a wire brush to remove oil and rust therefrom. The roughness can improve the bonding strength between the bearing alloy and the low-carbon steel plate substrate.

In the above bearing material, the thickness of the substrate may be a thickness conventional in the art, and is preferably 1 to 3 mm.

The invention also provides a preparation method of the bearing material, which can be a powder metallurgy method conventional in the field.

In the above preparation method, the preparation method preferably includes the steps of: and spreading the powder of the bearing alloy blank on the substrate, and carrying out primary sintering, cold rolling and secondary sintering.

Wherein the primary sintering is used for connecting the powder of the bearing alloy blank which is loosely laid on the substrate with each other and with the substrate and forming a loose and porous bearing alloy coating. The atmosphere of the primary sintering is preferably an ammonia decomposition atmosphere. The primary sintering temperature is preferably 800-1000 ℃, more preferably 910-920 ℃. The time for the primary sintering is preferably 30 to 120 minutes, more preferably 30 to 45 minutes.

Wherein the purpose of the cold rolling is to compact the loose and porous bearing alloy coating obtained by the primary sintering. The cold rolling deformation ratio is preferably 50% to 95%, more preferably 90% to 95%.

Wherein the secondary sintering is to further densify the porous bearing alloy coating to a relative density of 95-99.5%. The temperature of the secondary sintering is preferably 750-950 ℃, more preferably 870-880 ℃. The time for the secondary sintering is preferably 30 to 120 minutes, more preferably 30 to 45 minutes.

Wherein the secondary sintering is preferably followed by planarization. The purpose of the leveling is to level the billet obtained by the secondary sintering. The leveling is usually a leveler. The leveling deformation rate is preferably 2% -5%, and the leveling precision is +/-0.02 mm.

And after the flattening, the steel sheets can be cut to obtain sizes of different models, and then are packaged and delivered out of a factory.

The invention also provides a bearing material prepared by the preparation method of the bearing material.

The invention also provides application of the bearing material as a bearing material for a marine engine. Preferably, the material is used as a sliding bearing material for a marine engine. More preferably, the bearing bush is used for a marine engine.

The above preferred conditions can be arbitrarily combined to obtain preferred embodiments of the present invention without departing from the common general knowledge in the art.

The reagents and starting materials used in the present invention are commercially available.

The positive progress effects of the invention are as follows: the preparation method of the bearing alloy and the bearing material takes the nickel-aluminum bronze powder as the raw material, has simpler process, higher yield and lower production cost, and is easier to realize industrial production. In the bearing alloy and the bearing material prepared by the preparation method, the graphite powder and the nickel-aluminum bronze powder are in a uniform mixing state, the interface bonding strength between the graphite powder and the nickel-aluminum bronze powder is high, the friction reduction performance and the wear resistance performance are good, and the corrosion resistance performance is good.

Drawings

FIG. 1 is a process flow diagram for preparing a bearing material according to various embodiments of the present invention;

FIG. 2 is a schematic structural diagram of a bearing material prepared according to various embodiments of the present invention.

Detailed Description

The invention is further illustrated by the following examples, which are not intended to limit the scope of the invention. The experimental methods without specifying specific conditions in the following examples were selected according to the conventional methods and conditions, or according to the commercial instructions.

In the following examples, the average particle size of the graphite powder was 30 to 50 μm; the chemical composition of the nickel-aluminum bronze powder is as follows: c is more than 0 and less than or equal to 0.1 wt%, Si is more than 0 and less than or equal to 0.15 wt%, Mn: 0.8-2.5 wt%, Pb more than 0 and less than or equal to 0.02 wt%, Fe: 4-5 wt%, Al: 8.5-10 wt%, Ni: 4-5 wt% of Cu, and the balance being Cu, wherein the nickel-aluminum bronze powder is prepared by a conventional aerosol method or a water-mist method, the average particle size of the nickel-aluminum bronze powder is 50-200 mu m, and the nickel-aluminum bronze powder with an oxide film removed is obtained by the following method: after being treated by dilute hydrochloric acid with the mass fraction of 5 wt%, the mixture is washed for 3 to 5 times by pure water; the chemical composition of the low-carbon steel plate substrate is as follows: c is more than 0 and less than or equal to 0.03 wt%, Si is more than 0 and less than or equal to 0.05 wt%, Mn is more than 0 and less than or equal to 0.5 wt%, P is more than 0 and less than or equal to 0.035 wt%, S is more than 0 and less than or equal to 0.025 wt%, and the balance is Fe; the thickness of the low-carbon steel plate substrate is 1-3 mm; the leveling precision is +/-0.02 mm.

In the following examples, the polyvinyl alcohol used was 1788, having an average molecular weight of 74800, and manufactured by conifer chemical company, guangzhou.

In the following examples, the ammonia decomposition atmosphere is a mixed atmosphere of hydrogen and nitrogen.

Example 1

(1) Bearing alloy blank, bearing alloy and preparation method of bearing material

As shown in figure 1, graphite powder and nickel-aluminum bronze powder are weighed according to the mass ratio of 3:97, and the nickel-aluminum bronze powder is acid-washed and water-washed and then poured into a stirrer together with the graphite powder for mixing to obtain mixed powder. Preparing a mixed aqueous solution with the mass fraction of 35 wt% of nickel nitrate and the mass fraction of 7 wt% of polyvinyl alcohol, adding the mixed aqueous solution into the mixed powder, wherein the mass ratio of the mixed solution to the nickel-aluminum bronze powder is 1:6, stirring for 3 hours in a stirrer, drying at 100 ℃, heating to 400 ℃ in an ammonia decomposition atmosphere, and preserving heat for 180 minutes. And putting the obtained block into a rolling machine to be crushed to obtain the bearing alloy blank.

And (3) polishing the surface of the mild steel plate to the roughness Ra25 by using a steel wire brush. And loosely loading and paving the crushed bearing alloy blank on the polished surface of the low-carbon steel plate, wherein the powder paving thickness is 2 mm. And (3) carrying out primary sintering on the low-carbon steel plate with the powder spread on the surface in an ammonia decomposition atmosphere, wherein the primary sintering temperature is 910 ℃, the primary sintering time is 45 minutes, the deformation rate of cold rolling after the primary sintering is 90%, the secondary sintering temperature is 870 ℃, the secondary sintering time is 45 minutes, and the flat deformation rate is 2%, so that the bearing material shown in the figure 2 is obtained.

(2) Effect embodiment and Effect data

And (3) carrying out a friction wear test and a salt spray test on one surface of the obtained bearing material with the bearing alloy blank. The load of the friction and wear test is 200N, the rotating speed is 100r/min, the counter-grinding is carried out for 30min under the condition of dry friction, and the counter-grinding ball is 440# stainless steel with the diameter of 6mm and the hardness of 60-62 HRC. Before the experiment, the working surface is uniformly polished by metallographic abrasive paper and is put into an acetone ultrasonic cleaner for cleaning for 15 minutes. After the experiment, the material was weighed to lose weight, and then its wear rate was calculated. The corrosion resistance of the material is tested by adopting a neutral salt spray test, which specifically comprises the following steps: the salt spray test adopts 5 percent of sodium chloride aqueous solution by mass percent as the solution for spraying, the test temperature is 25 ℃, and the sedimentation rate of the salt spray is 0.02mL/cm²h, after 72 hours, the corrosion resistance grade is measured.

The test shows that the friction coefficient of the bearing alloy is 0.11, the wear rate is 1.5mg/m, and the corrosion resistance grade is 9.

Example 2

The mass ratio of graphite powder to nickel-aluminum bronze powder was changed to 2.95:97.05, and the other preparation conditions were the same as in example 1.

By the same test method as in example 1, the obtained bearing alloy had a friction coefficient of 0.13, a wear rate of 2.2mg/m and a corrosion resistance rating of 9.

Example 3

The mass ratio of graphite powder to nickel-aluminum bronze powder was changed to 3.05:96.85, and the other preparation conditions were the same as in example 1.

By the same test method as in example 1, the obtained bearing alloy had a friction coefficient of 0.12, a wear rate of 2.0mg/m, and a corrosion resistance rating of 9.

Example 4

The temperature of the primary sintering was 920 ℃, the time of the primary sintering was 30 minutes, the deformation rate of the cold rolling after the primary sintering was 95%, and the other preparation conditions were the same as in example 1.

By the same test method as in example 1, the obtained bearing alloy had a friction coefficient of 0.11, a wear rate of 1.7mg/m, and a corrosion resistance rating of 9.

Example 5

The temperature of the secondary sintering was 880 ℃, the time of the secondary sintering was 30 minutes, the leveling deformation rate was 5%, and the other preparation conditions were the same as in example 1.

By the same test method as in example 1, the obtained bearing alloy had a friction coefficient of 0.12, a wear rate of 1.9mg/m, and a corrosion resistance rating of 9.

Comparative example 1

The friction coefficient and wear rate of the conventional CuSn10Pb10 sliding bearing material were measured to be 0.22 and 8.9mg/m, respectively, and the corrosion resistance rating was 6, using the same test method as in example 1.

As can be seen, the bearing material according to the embodiment of the present invention has more excellent wear resistance, friction reduction, and corrosion resistance.

Comparative example 2

Weighing graphite powder and nickel-aluminum bronze powder according to the mass ratio of 3:97, pickling and washing the nickel-aluminum bronze powder, pouring the nickel-aluminum bronze powder and the graphite powder into a stirrer for mixing, drying, and loosely paving the mixed powder on the surface of a roughened low-carbon steel plate, wherein the powder paving thickness is 2 mm. And (2) carrying out primary sintering on the low-carbon steel plate with the powder spread on the surface in an ammonia decomposition atmosphere, wherein the primary sintering temperature is 910 ℃, the primary sintering time is 45 minutes, the cold rolling deformation rate after the primary sintering is 90 percent, the secondary sintering temperature is 870 ℃, the secondary sintering time is 45 minutes, and the flat deformation rate is 2 percent, thus obtaining the bearing material.

The friction coefficient and wear rate of the bearing alloy prepared by using the graphite powder and the nickel-aluminum bronze powder which were not treated with the mixed solution of the present invention were 0.53 and 51.6mg/m, respectively, and the corrosion resistance rating thereof was 9, using the same test method as in example 1.

Therefore, the bearing alloy prepared by using the graphite powder and the nickel-aluminum bronze powder which are not treated by the mixed solution of the invention as raw materials has poor wear resistance and antifriction property.

Comparative example 3

Only nickel-aluminum bronze powder is used as a raw material, and graphite powder is not added. And after acid washing and drying, the nickel-aluminum bronze is loosely arranged and paved on the surface of a low-carbon steel plate, and the paving thickness is 2 mm. And (2) carrying out primary sintering on the low-carbon steel plate with the powder spread on the surface in an ammonia decomposition atmosphere, wherein the primary sintering temperature is 910 ℃, the primary sintering time is 45 minutes, the cold rolling deformation rate after the primary sintering is 90 percent, the secondary sintering temperature is 870 ℃, the secondary sintering time is 45 minutes, and the flat deformation rate is 2 percent, thus obtaining the bearing material.

The friction coefficient and wear rate of the bearing alloy prepared from the nickel-aluminum bronze powder without graphite powder were 0.39 and 13.8mg/m, respectively, and the corrosion resistance rating thereof was 9, using the same test method as in example 1.

Therefore, the wear resistance and the antifriction property of the bearing alloy prepared from the nickel-aluminum bronze powder without adding the graphite powder are poor.

In conclusion: compared with the common CuSn10Pb10 sliding bearing material, the bearing material has better corrosion resistance, and is more suitable for being used as the sliding bearing material of the marine engine.

While specific embodiments of the invention have been described above, it will be appreciated by those skilled in the art that this is by way of example only, and that the scope of the invention is defined by the appended claims. Various changes and modifications to these embodiments may be made by those skilled in the art without departing from the spirit and scope of the invention, and these changes and modifications are within the scope of the invention.

Claims

1. The preparation method of the bearing alloy blank is characterized by comprising the following steps: in the mixed solution, after nickel nitrate coated films are respectively formed on the surfaces of graphite powder and nickel-aluminum bronze powder, reducing the nickel nitrate coated films into nickel coated films in a reducing atmosphere; the nickel-aluminum bronze powder is nickel-aluminum bronze powder with an oxidation film removed; the mixed solution is an aqueous solution containing nickel nitrate and polyvinyl alcohol, and the average molecular weight of the polyvinyl alcohol is in the range of 16000-130000; the reducing atmosphere is an atmosphere containing hydrogen.

2. The method for producing a bearing alloy billet as claimed in claim 1, wherein the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 2-5: 98-95.

3. The method for producing a bearing alloy billet as claimed in claim 2, wherein the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 2-4: 98-94.

4. The method for producing a bearing alloy material blank according to claim 3, wherein the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 2.95 to 3.05:97.05 to 96.85.

5. The method for producing a bearing alloy material blank according to claim 4, wherein the mass ratio of the graphite powder to the nickel-aluminum bronze powder is 3: 97.

6. The method for preparing a bearing alloy blank according to claim 1, wherein the mass fraction of the nickel nitrate in the mixed solution is 20 to 50 percent;

the mass fraction of the polyvinyl alcohol in the mixed solution is 5-10%;

the product model of the polyvinyl alcohol is polyvinyl alcohol 1788;

the mass ratio of the mixed solution to the nickel-aluminum bronze powder is 1: 4-8.

7. The method for producing a bearing alloy billet according to claim 6, wherein the mass fraction of the nickel nitrate in the mixed solution is 35% to 40%.

8. The method for producing a bearing alloy billet according to claim 6, wherein the mass fraction of the polyvinyl alcohol in the mixed solution is 7% to 8%.

9. The method of making a bearing alloy billet in accordance with claim 6 in which the polyvinyl alcohol has an average molecular weight of 74800.

10. The method for producing a bearing alloy material blank according to claim 6, wherein the mass ratio of the mixed solution to the nickel aluminum bronze powder is 1: 6.

11. The method of producing a bearing alloy billet according to claim 1, wherein the graphite powder has an average particle diameter of 30 to 50 μm;

the chemical composition of the nickel-aluminum bronze powder is as follows: c is more than 0 and less than or equal to 0.1 wt%, Si is more than 0 and less than or equal to 0.15 wt%, Mn: 0.8-2.5 wt%, Pb more than 0 and less than or equal to 0.02 wt%, Fe: 4-5 wt%, Al: 8.5-10 wt%, Ni: 4-5 wt% of Cu, and the balance being Cu;

The nickel-aluminum bronze powder is prepared by adopting an aerosol method or a water mist method;

the average grain diameter of the nickel-aluminum bronze powder is 50-200 mu m;

the nickel-aluminum bronze powder with the oxide film removed is obtained by the following method: treating with 5 wt% dilute hydrochloric acid, and cleaning with pure water for 3-5 times;

the mixing time is 3-6 h;

drying before the reduction;

the reducing atmosphere is a hydrogen atmosphere, or the reducing atmosphere is a mixed atmosphere of hydrogen and nitrogen;

the temperature of the reduction is 400-600 ℃;

the reduction time is 30-180 minutes;

the reduction is followed by a crushing treatment.

12. The method for preparing a bearing alloy blank according to claim 11, wherein the drying temperature is 100-110 ℃.

13. A bearing alloy blank produced by the method for producing a bearing alloy blank according to any one of claims 1 to 12.

14. A bearing alloy, wherein a raw material of the bearing alloy is the bearing alloy billet according to claim 13.

15. A bearing material, characterized in that the bearing material is a layered structure, the bearing material comprising the bearing alloy according to claim 14 and a substrate, the bearing alloy being attached to the substrate.

16. A bearing material according to claim 15 wherein the bearing alloy has a thickness of from 0.5 to 2 mm.

17. The bearing material of claim 16 wherein the thickness of the bearing alloy is 0.5 to 1.5 mm.

18. The bearing material of claim 15, wherein the substrate is a low carbon steel sheet substrate having a chemical composition as follows: c is more than 0 and less than or equal to 0.03 wt%, Si is more than 0 and less than or equal to 0.05 wt%, Mn is more than 0 and less than or equal to 0.5 wt%, P is more than 0 and less than or equal to 0.035 wt%, S is more than 0 and less than or equal to 0.025 wt%, and the balance is Fe.

19. The bearing material of claim 15 wherein the contact surface of the substrate and the bearing alloy has a roughness of Ra 25.

20. The bearing material of claim 15, wherein the substrate has a thickness of 1-3 mm.

21. A method of producing a bearing material as claimed in any one of claims 15 to 20, wherein the production method is a powder metallurgy method.

22. A method of producing a bearing material as claimed in claim 21, comprising the steps of: and spreading the powder of the bearing alloy blank on the substrate, and carrying out primary sintering, cold rolling and secondary sintering.

23. The method for producing a bearing material according to claim 22, wherein an atmosphere of the primary sintering is an ammonia decomposition atmosphere.

24. The method for preparing a bearing material as claimed in claim 22, wherein the primary sintering temperature is 800-1000 ℃.

25. The method for preparing a bearing material as claimed in claim 24, wherein the primary sintering temperature is 910 ℃ and 920 ℃.

26. The method for producing a bearing material according to claim 22, wherein the time for the primary sintering is 30 to 120 minutes.

27. The method for producing a bearing material according to claim 26, wherein the time for the primary sintering is 30 to 45 minutes.

28. The method of producing a bearing material according to claim 22, wherein the cold rolling has a deformation ratio of 50% to 95%.

29. The method for producing a bearing material according to claim 28, wherein the cold rolling has a deformation ratio of 90% to 95%.

30. The method for preparing a bearing material as claimed in claim 22, wherein the temperature of the secondary sintering is 750-950 ℃.

31. The method for preparing a bearing material as claimed in claim 30, wherein the temperature of the secondary sintering is 870-880 ℃.

32. The method for producing a bearing material according to claim 22, wherein the time for the secondary sintering is 30 to 120 minutes.

33. The method for producing a bearing material according to claim 32, wherein the time for the secondary sintering is 30 to 45 minutes.

34. The method of producing a bearing material according to claim 22, wherein the secondary sintering is followed by flattening.

35. The method for producing a bearing material according to claim 34, wherein the flattening deformation ratio is 2% to 5%, and the flattening accuracy is ± 0.02 mm.

36. Use of a bearing material according to any one of claims 15 to 20 as a plain bearing material for a marine engine.