CN114210966B - Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof - Google Patents
Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof Download PDFInfo
- Publication number
- CN114210966B CN114210966B CN202111510085.4A CN202111510085A CN114210966B CN 114210966 B CN114210966 B CN 114210966B CN 202111510085 A CN202111510085 A CN 202111510085A CN 114210966 B CN114210966 B CN 114210966B
- Authority
- CN
- China
- Prior art keywords
- powder
- copper
- friction material
- friction coefficient
- powder metallurgy
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 title claims abstract description 94
- 239000002783 friction material Substances 0.000 title claims abstract description 70
- 239000010949 copper Substances 0.000 title claims abstract description 67
- 229910052802 copper Inorganic materials 0.000 title claims abstract description 64
- 238000004663 powder metallurgy Methods 0.000 title claims abstract description 47
- 238000002360 preparation method Methods 0.000 title claims abstract description 12
- 239000000463 material Substances 0.000 claims abstract description 17
- 238000000034 method Methods 0.000 claims abstract description 11
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 39
- 239000000843 powder Substances 0.000 claims description 37
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 claims description 32
- 238000006722 reduction reaction Methods 0.000 claims description 27
- 238000005245 sintering Methods 0.000 claims description 23
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 22
- 238000010438 heat treatment Methods 0.000 claims description 17
- 239000000203 mixture Substances 0.000 claims description 16
- 229910000604 Ferrochrome Inorganic materials 0.000 claims description 15
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 claims description 15
- 229910002804 graphite Inorganic materials 0.000 claims description 13
- 239000010439 graphite Substances 0.000 claims description 13
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 12
- 239000003921 oil Substances 0.000 claims description 12
- 239000004372 Polyvinyl alcohol Substances 0.000 claims description 11
- 229920002451 polyvinyl alcohol Polymers 0.000 claims description 11
- 229910000831 Steel Inorganic materials 0.000 claims description 8
- 239000010959 steel Substances 0.000 claims description 8
- 238000000498 ball milling Methods 0.000 claims description 7
- 238000002156 mixing Methods 0.000 claims description 7
- 238000004321 preservation Methods 0.000 claims description 7
- 238000007873 sieving Methods 0.000 claims description 7
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims description 6
- 229910045601 alloy Inorganic materials 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 6
- 239000004615 ingredient Substances 0.000 claims description 6
- 239000010705 motor oil Substances 0.000 claims description 6
- 238000003825 pressing Methods 0.000 claims description 6
- 238000005303 weighing Methods 0.000 claims description 6
- 238000001035 drying Methods 0.000 claims description 5
- 238000000465 moulding Methods 0.000 claims description 5
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 claims description 4
- 238000013461 design Methods 0.000 claims description 4
- 239000001257 hydrogen Substances 0.000 claims description 4
- 229910052739 hydrogen Inorganic materials 0.000 claims description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 4
- 229910000599 Cr alloy Inorganic materials 0.000 claims description 3
- 241000357293 Leptobrama muelleri Species 0.000 claims description 3
- 229910021529 ammonia Inorganic materials 0.000 claims description 3
- 239000000788 chromium alloy Substances 0.000 claims description 3
- DYRBFMPPJATHRF-UHFFFAOYSA-N chromium silicon Chemical compound [Si].[Cr] DYRBFMPPJATHRF-UHFFFAOYSA-N 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 238000000354 decomposition reaction Methods 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 3
- 239000007789 gas Substances 0.000 claims description 3
- 229910052742 iron Inorganic materials 0.000 claims description 3
- 238000011068 loading method Methods 0.000 claims description 3
- 238000007790 scraping Methods 0.000 claims 1
- 230000000694 effects Effects 0.000 abstract description 4
- 239000011159 matrix material Substances 0.000 abstract description 3
- 229910000881 Cu alloy Inorganic materials 0.000 abstract description 2
- 230000001050 lubricating effect Effects 0.000 abstract description 2
- 239000007787 solid Substances 0.000 abstract description 2
- 238000012360 testing method Methods 0.000 description 11
- 238000005299 abrasion Methods 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 238000011056 performance test Methods 0.000 description 3
- 239000011651 chromium Substances 0.000 description 2
- 230000009977 dual effect Effects 0.000 description 2
- 239000010410 layer Substances 0.000 description 2
- 239000011148 porous material Substances 0.000 description 2
- 239000002994 raw material Substances 0.000 description 2
- 238000012795 verification Methods 0.000 description 2
- 229920002748 Basalt fiber Polymers 0.000 description 1
- 241000220317 Rosa Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000000429 assembly Methods 0.000 description 1
- 230000000712 assembly Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 230000003301 hydrolyzing effect Effects 0.000 description 1
- 238000009776 industrial production Methods 0.000 description 1
- 238000003754 machining Methods 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000000178 monomer Substances 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 230000000379 polymerizing effect Effects 0.000 description 1
- 229920002689 polyvinyl acetate Polymers 0.000 description 1
- 239000011118 polyvinyl acetate Substances 0.000 description 1
- 230000001681 protective effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000001878 scanning electron micrograph Methods 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 238000005482 strain hardening Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 229920003169 water-soluble polymer Polymers 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F7/00—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression
- B22F7/06—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools
- B22F7/08—Manufacture of composite layers, workpieces, or articles, comprising metallic powder, by sintering the powder, with or without compacting wherein at least one part is obtained by sintering or compression of composite workpieces or articles from parts, e.g. to form tipped tools with one or more parts not made from powder
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- F16D69/00—Friction linings; Attachment thereof; Selection of coacting friction substances or surfaces
- F16D69/02—Composition of linings ; Methods of manufacturing
- F16D69/027—Compositions based on metals or inorganic oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/04—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling
- B22F2009/043—Making metallic powder or suspensions thereof using physical processes starting from solid material, e.g. by crushing, grinding or milling by ball milling
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Inorganic Chemistry (AREA)
- Composite Materials (AREA)
- Materials Engineering (AREA)
- Powder Metallurgy (AREA)
Abstract
The copper-based powder metallurgy friction material with high stable friction coefficient and the preparation method thereof optimize the components and the preparation process of the material, exert the system matching effect of a copper alloy matrix, a lubricating component and a solid component, and have the advantages of high strength, low expansion rate, small deformation and good wear resistance, so that the fluctuation range of the friction coefficient of the friction material is not more than +/-5 percent, the average friction coefficient is not more than 0.31 and not more than cp percent, the fluctuation range of the friction coefficient is not more than +/-5 percent, and the linear wear amount of the friction material is not more than 0.0038 mm/surface and times. The friction material obtained by the invention has good mechanical strength, is suitable for working conditions with positive pressure of 2.032KN and speed of 75m/s, has the advantages of high strength, low expansion rate, small deformation, good wear resistance and the like, and has no phenomena of falling off, falling blocks, clamping stagnation, bonding and the like of a friction layer in use, and has stable braking curve and stable and reliable braking process.
Description
Technical Field
The invention relates to the field of powder metallurgy copper-based brake materials, in particular to a copper-based powder metallurgy friction material with a high stable friction coefficient and a preparation method thereof.
Background
Friction materials based on copper among powder metallurgy friction materials are widely used in the fields of machining, transportation, aviation navigation, and the like due to their excellent product characteristics. However, the existing copper-based friction material still has the problems of low hardness, high wear rate and the like, and particularly has the phenomenon that the fluctuation range of friction coefficient exceeds +/-10% in the high-speed braking process, so that the braking distance is unstable, and a higher danger coefficient is generated. Therefore, the copper-based powder metallurgy friction material with moderate friction coefficient and stable braking is prepared and has great significance.
In the invention creation of publication No. CN108907177A, a copper-based powder metallurgy friction material for high-speed train braking is provided, only the preparation process and material components are described, the friction test result of the verification material is single, only the friction coefficient and the average abrasion amount are obtained, and the friction stability is not illustrated.
In the invention creation of publication No. CN106641049, a method for preparing a brake pad by basalt fiber is disclosed, and the brake pad can reduce the content of metal components of the brake pad and reduce noise and abrasion of the brake pad, but the fluctuation range of friction coefficient is not described.
In the invention creation of publication No. CN106011520A, a dry copper-based powder metallurgy friction material for a clutch is provided, and the stability coefficient of the friction coefficient of the material is verified to be 0.59 through a friction test, but the fluctuation range of the friction coefficient is not marked.
The invention creation of the publication No. CN104480342A discloses a high friction coefficient corrosion-resistant copper-based brake material and a preparation method thereof, wherein the maximum bearing load of the material is 6.6MPa, and the dynamic friction coefficient is 0.32-0.37, but the friction stability is not illustrated.
In the invention creation of publication numbers CN109988937A and CN109513939A, only a preparation process of copper-based powder metallurgy material is provided, and test verification is not carried out on the prepared copper-based material, so that whether the prepared copper-based material meets the technical requirements of products cannot be described.
Disclosure of Invention
The invention provides a copper-based powder metallurgy friction material with a high stable friction coefficient and a preparation method thereof, aiming at solving the friction stability of the copper-based powder metallurgy friction material.
The copper-based powder metallurgy friction material with high stable friction coefficient provided by the invention consists of 48-52% of electrolytic copper powder, 18-24% of reduced iron powder, 12-16% of graphite, 3-6% of ferrochrome, 2-4% of aluminum oxide, 2-4% of molybdenum powder, 2-5% of precipitated barium sulfate and 3-6% of polyvinyl alcohol powder; the percentages are mass percentages.
The Cu content in the electrolytic copper powder is more than or equal to 99.8 percent. The content of Fe in the reduced iron powder is more than or equal to 98.5 percent. The content of C in the graphite is more than or equal to 99.99 percent; the graphite is +80 mesh flake. Cr in the ferrochrome is more than or equal to 60 percent. MoS 2 in the molybdenum powder is more than or equal to 99 percent. Al 2O3 in the aluminum oxide is more than or equal to 99 percent. BaSO 4 in the precipitated barium sulfate is more than or equal to 98 percent. The (C 2H4 O) n in the polyvinyl alcohol powder is more than or equal to 90.5 percent.
The specific process for preparing the copper-based powder metallurgy friction material with the high stable friction coefficient provided by the invention comprises the following steps:
step 1, reduction of copper powder and iron powder:
Copper powder and iron powder are respectively placed in a reduction furnace for reduction reaction;
When the copper powder is subjected to reduction reaction, the reduction temperature is 380-450 ℃, and the heating rate is 150 ℃/h; when the iron powder is subjected to reduction reaction, the reduction temperature is 620-700 ℃, and the heating rate is 200 ℃/h; the heat preservation time of the reduction reaction of the copper powder and the iron powder is 2-3 h.
Step 2, ball milling:
And respectively putting the copper powder and the iron powder which are qualified in reduction into a ball mill to perform ball milling for 0.5-1 h. Steel ball: copper powder = steel ball: iron powder = 10:1. The proportion is weight ratio.
In the ball-milled steel ball, the diameter of the big ball is 96mm, the diameter of the small ball is 40mm, the ratio of the big ball to the small ball=3:1 is the weight ratio.
Step 3, drying:
Graphite powder, molybdenum powder, silicon-chromium alloy and barium sulfate powder are classified and placed into an oven, and the oven is heated to 120-150 ℃ and kept for 3.0-6.0 h so as to remove the moisture in the various powders.
The heating time of the oven is 30min.
Step 4, sieving:
Sieving the dried ferrochrome alloy powder, graphite powder, barium sulfate and aluminum oxide powder respectively, and taking-200 meshes of ferrochrome alloy powder, +80 meshes of graphite powder, -400 meshes of barium sulfate powder and-100 meshes of aluminum oxide powder for standby.
Step 5, batching and mixing:
Sequentially weighing electrolytic copper powder, reduced iron powder, graphite, ferrochrome, aluminum oxide, molybdenum powder, precipitated barium sulfate and polyvinyl alcohol powder according to the mass percentage, and mixing the weighed materials and mixed oil for 20-24 hours in a double-cone mixer with the war speed of 40-50 r/min; the mixture is obtained.
The ratio of the sum of the ingredients to the mixed oil is 1:10; the ratio is weight ratio. Wherein the weight unit of the ingredients is kg, and the weight unit of the mixed oil is ml. The mixed oil is a mixture of gasoline and engine oil; the gasoline comprises the following components: engine oil = 1:1; the ratio is weight ratio
Step 6, pressing:
And weighing the obtained mixture according to the design requirement of the product, pouring the mixture into a mold, and carrying out strickling and cold press molding to obtain a plurality of pressed compacts of the copper-based powder metallurgy friction material with the density of 5.8-6.5 g/cm 3.
In the cold press molding, the pressure born by the unit area of the iron-based powder metallurgy friction material compact is 500-600 MPa, and the pressure maintaining time is 10s.
Step 7, sintering:
and respectively assembling the obtained pressed compact of the copper-based powder metallurgy friction material and the steel back into an assembly. And (5) loading the stacked assembly into a pressurized sintering furnace for sintering to obtain the copper-based powder metallurgy friction material.
During sintering, heating the pressurized sintering furnace to 120 ℃ at 5 ℃/min under the condition of introducing hydrogen or ammonia decomposition gas, and preserving heat for 1.5-2 h; after the heat preservation is finished, the temperature is increased to 700 ℃ at 2 ℃/min, and the heat preservation is carried out for 1.5 to 2 hours; continuously heating to the sintering temperature of 860-890 ℃ at 5 ℃/min, pressurizing to the sintering pressure of 0.5-0.7/MPa, and maintaining the pressure and the temperature for 3-5 h. After sintering, cooling the water to below 60 ℃ and releasing pressure, and discharging.
The hardness of the obtained copper-based powder metallurgy friction material is 35-42 HRF, the average friction coefficient is 0.31-0.34, the fluctuation range of the friction coefficient is 3.03-4.61, and the wear rate is 0.0024-0.0038 mm/surface.
The copper-based powder metallurgy friction material with a fluctuation range of friction coefficient not exceeding +/-5%, certain strength and high stable friction coefficient is developed by adjusting the formula of the copper-based powder metallurgy friction material. The average friction coefficient of the friction material is more than or equal to 0.31 and less than or equal to cp and less than or equal to 0.34, the fluctuation range of the friction coefficient is not more than +/-5% of the average friction coefficient, and the linear abrasion loss of the friction material is less than or equal to 0.0038 mm/surface per time.
Compared with the prior art, the invention has the following beneficial effects:
1. the invention utilizes the powder metallurgy preparation technology to scientifically design various component compositions of the material, and provides the proportion of various raw materials of the copper-based powder metallurgy friction material and the technological scheme and parameters in the whole production process of raw material reduction, ball milling, drying, sieving, batching, mixing, pressing, sintering and the like in detail.
2. The invention provides the copper-based powder metallurgy friction material with good mechanical strength and high stable friction coefficient and the preparation method thereof, which are suitable for working conditions of positive pressure of 2.032KN and speed of 75m/s by scientifically designing various component compositions of the material and exerting system matching effects of a copper alloy matrix, a lubricating component, a solid component and the like.
3. The powder metallurgy copper-based friction material manufactured according to the invention has the advantages of high strength, low expansion rate, small deformation, good wear resistance and the like. The friction pair formed by the braking part with the friction layer thickness smaller than 5mm and the 30CrMnSi (HRC 34-42) steel material, which is made of the powder metallurgy copper-based friction material, can reach the friction coefficient of 0.31- cp -0.34 when the friction pair is used under the condition of 75m/s, the fluctuation range of the friction coefficient is not more than +/-5% of the average friction coefficient, and the linear abrasion loss is not more than 0.0038 mm/surface-times. As shown in fig. 3, it can be seen from the graph that under certain pressure and rotation speed, after the prepared copper-based friction material and the friction dual material form good friction contact, the friction coefficient trend of the copper-based friction material is stable, and the fluctuation range is not more than +/-5% of the average friction coefficient, so that the technical requirements of products are met.
4. The friction material manufactured according to the invention has no phenomena of falling off, clamping stagnation, bonding and the like of a friction layer in the friction process, has stable curve and is stable and reliable in braking.
5. The invention has the beneficial effects that the polyvinyl alcohol is a water-soluble polymer which is obtained by hydrolyzing polyvinyl acetate instead of polymerizing monomers. The polymer has stable chemical property, can not influence the structure of the copper-based friction material, and has the characteristic of easy volatilization under the high temperature condition, so that the pores in the structure are uniformly distributed.
6. The invention has the beneficial effects that the polyvinyl alcohol in the pressed compact is effectively eliminated and a certain amount of air holes are formed in a continuous temperature rising and heat preserving mode, and the air holes can efficiently accelerate the diffusion and fluidity of copper under the high temperature condition, so that the copper is distributed more uniformly in the friction material, and the stability in the braking process is improved. As shown in fig. 2, the copper-based matrix is tightly connected with other components and has a certain pore, so that the thermal stability of the copper-based friction material in the friction process is increased.
Drawings
FIG. 1 is a sample of copper-based friction material obtained according to the present invention.
Fig. 2 is an SEM image of a copper-based friction material obtained according to the present invention.
FIG. 3 is a graph showing the frictional wear performance test of a sample of the copper-based powder metallurgy friction material obtained according to the present invention, measured at inertia of 0.05Kg.m 2, forward pressure of 2.032KN, radius of 0.032m, and rotation speed of 8061 rpm; in the figure, curve 1 is a friction coefficient curve measured with braking time, curve 2 is a rotational speed curve measured with braking time, and curve 3 is a given forward pressure curve at braking.
FIG. 4 is a graph showing the surface of a copper-based friction material sample after friction testing.
Fig. 5 is a flow chart of the present invention.
Detailed Description
The invention relates to a high-stability friction coefficient copper-based powder metallurgy friction material which is composed of 48-52% of electrolytic copper powder, 18-24% of reduced iron powder, 12-16% of graphite, 3-6% of ferrochrome, 2-4% of aluminum oxide, 2-4% of molybdenum powder, 2-5% of precipitated barium sulfate and 3-6% of polyvinyl alcohol powder, wherein the percentages are mass percentages.
The invention is specifically described by 4 embodiments. The components of each example are shown in Table 1:
The components of each embodiment example provided by the invention are shown in Table 1, wherein the content of each component is in mass percent (%).
TABLE 1
The Cu content in the electrolytic copper powder is more than or equal to 99.8%, and the execution standard is GB/T5246-2007.
The content of Fe in the reduced iron powder is more than or equal to 98.5%, and the execution standard is GB/T4136-94.
The content of C in the graphite is more than or equal to 99.99%, and the implementation standard is GB/T3518-95. The graphite is +80 mesh flake.
Cr in the ferrochrome is more than or equal to 60 percent, and the execution standard is GB/T5683-2008
MoS 2 in the molybdenum powder is more than or equal to 99%, and the execution standard is GB/T23271-2009.
Al 2O3 in the aluminum oxide is more than or equal to 99 percent, and the execution standard is GB/T11200.2-2008.
BaSO 4 in the precipitated barium sulfate is more than or equal to 98 percent, and the execution standard is GB/T2899-2008.
The (C 2H4 O) n in the polyvinyl alcohol powder is more than or equal to 90.5%, and the standard GB/T19001-2016 is implemented.
The invention also provides a method for preparing the copper-based powder metallurgy friction material.
The specific process for preparing the copper-based powder metallurgy friction material comprises the following steps:
Step 1, reduction of copper powder and iron powder: copper powder and iron powder are respectively placed in a reduction furnace, the temperature of the reduction furnace is raised, and hydrogen is used as a protective atmosphere for reduction, so that the oxygen content and the work hardening phenomenon in the copper powder and the iron powder are eliminated. Reduction temperature: the copper powder is at 380-450 ℃ and the heating rate is 150 ℃/h; the iron powder is at 620-700 ℃ and the heating rate is 200 ℃/h; the heat preservation time of the reduction reaction of the copper powder and the iron powder is 2-3 h.
And obtaining the reduced copper powder and the reduced iron powder. The qualified copper powder is in a rose red spongy state, and the iron powder is in a silver gray spongy state.
The reduction temperature process parameters of the examples proposed in the present invention are shown in table 2:
TABLE 2
Step 2, ball milling: and respectively putting the copper powder and the iron powder which are qualified in reduction into a ball mill to perform ball milling for 0.5-1 h. Steel ball copper powder/iron powder=10:1. The proportion is weight ratio.
The steel ball comprises a big ball and a small ball. The diameter of the big ball is 96mm, the diameter of the small ball is 40mm, and the ratio of big ball to small ball=3:1 is weight ratio.
Step 3, drying: graphite powder, molybdenum powder, silicon-chromium alloy and barium sulfate powder are classified and placed into an oven, and the oven is heated to 120-150 ℃ and kept for 3.0-6.0 h so as to remove the moisture in the various powders.
The heating time of the oven is 30min.
The drying process parameters of the examples proposed in the present invention are shown in table 3:
TABLE 3 Table 3
Step4, sieving: sieving the dried ferrochrome alloy powder, graphite powder, barium sulfate and aluminum oxide powder respectively, and taking-200 meshes of ferrochrome alloy powder, +80 meshes of graphite powder, -400 meshes of barium sulfate powder and-100 meshes of aluminum oxide powder for standby.
Step 5, batching and mixing: sequentially weighing 48-52% of electrolytic copper powder, 18-24% of reduced iron powder, 12-16% of graphite, 3-7% of ferrochrome, 2-4% of aluminum oxide, 2-4% of molybdenum powder, 2-5% of precipitated barium sulfate, 3-7% of polyvinyl alcohol powder and mixed oil according to the mass percentage, and mixing in a double-cone mixer for 20-24 hours to ensure that the particles are uniformly distributed; the mixture is obtained.
The rotating speed of the double-cone mixer is 40-50 r/min.
The ratio of the sum of the ingredients to the mixed oil is 1:10; the ratio is weight ratio. Wherein the weight unit of the ingredients is kg, and the weight unit of the mixed oil is ml.
The mixed oil is a mixture of gasoline and engine oil; the gasoline comprises the following components: engine oil = 1:1; the ratio is weight ratio.
TABLE 4 Table 4
Step 6, pressing: and weighing the obtained mixture according to the design requirement of the product, pouring the mixture into a die, strickling the mixture by a strickling device, and performing cold press molding on a 5000KN hydraulic press to obtain a pressed compact of the copper-based powder metallurgy friction material with the density of 5.8-6.5 g/cm 3. In the cold press molding, the pressure born by the unit area of the iron-based powder metallurgy friction material compact is 500-600 MPa, and the pressure maintaining time is 10s. A plurality of compacts of copper-based powder metallurgy friction materials are obtained.
The pressing process parameters of the examples proposed in the present invention are shown in table 5:
TABLE 5
Step 7, sintering: and respectively assembling the obtained pressed compact of the copper-based powder metallurgy friction material and the steel back into an assembly. The assemblies are stacked to form a column according to the prior art and are separated by a graphite backing plate.
And loading the stacked assembly into a pressurized sintering furnace for sintering.
Heating the pressurized sintering furnace to 120 ℃ at 5 ℃/min under the condition of introducing hydrogen or ammonia decomposition gas, preserving heat for 1.5-2 h, heating to 700 ℃ at 2 ℃/min, preserving heat for 1.5-2 h, heating to 860-890 ℃ at 5 ℃/min, pressurizing to 0.5-0.7/MPa, and preserving pressure and preserving heat for 3-5 h. And after sintering, cooling the copper-based powder metallurgical friction material to below 60 ℃ by water, releasing pressure, and discharging the copper-based powder metallurgical friction material.
The sintering process parameters of each embodiment proposed by the invention are shown in table 6:
TABLE 6
In order to verify the effect of the invention, the invention simulates specific working conditions, and the effect of the invention is verified through experiments.
The testing machine is an MM-3000 type friction and wear performance testing table; the friction material product sample specification is s=21 cm 2, r=0.032 m, where S is the surface area of the sample and r is the radius of the pattern; the dual material is 30CrMnSi, and the hardness is HRF 26-32.
Test conditions: friction material article j=0.05 kg·m 2, f=2.03 kn, n=8061 rpm; wherein J is inertia, F is forward pressure, and N is the rotation speed of the tester. The test environment was a dry environment.
The test results are: through friction and wear performance tests on an MM-3000 type friction and wear performance test bed, under the friction test conditions of inertia of 0.05 kg.m 2, forward pressure of 2.032KN and rotation speed of 8061rpm, the average friction coefficient of the copper-based friction material is between 0.31 and 0.34, the fluctuation range of the friction coefficient is not more than +/-5%, the absorption kinetic energy Ws of unit area is more than or equal to 1260.65J/cm 2, the average braking distance s is less than or equal to 116.32m, the friction braking time s is less than or equal to 2.89s, the linear wear amount of the friction material is less than or equal to 0.0038 MM/surface.times, the product technical requirement is met, and the copper-based friction material can be used for mass industrial production.
FIG. 4 is a surface of a copper-based friction material sample after a friction test. The copper-based friction material has complete surface, no phenomena of surface layer peeling, block falling, clamping stagnation, bonding and the like, and stable product performance.
The main physical and mechanical properties of the copper-based powder metallurgical friction materials produced according to the formulations in the examples described above are shown in table 7 below:
TABLE 7
Claims (7)
1. The copper-based powder metallurgy friction material with high stable friction coefficient is characterized by comprising 48-52% of electrolytic copper powder, 18-24% of reduced iron powder, 12-16% of graphite, 3-6% of ferrochrome, 2-4% of aluminum oxide, 2-4% of molybdenum powder, 2-5% of precipitated barium sulfate and 3-6% of polyvinyl alcohol powder; the percentages are mass percentages;
The Cu content in the electrolytic copper powder is more than or equal to 99.8%; the content of Fe in the reduced iron powder is more than or equal to 98.5%; the content of C in the graphite is more than or equal to 99.99 percent; the graphite is in a +80 mesh flake shape; cr in the ferrochrome is more than or equal to 60 percent; moS 2 in the molybdenum powder is more than or equal to 99 percent; al 2O3 in the aluminum oxide is more than or equal to 99 percent; baSO 4 in the precipitated barium sulfate is more than or equal to 98 percent; (C 2H4 O) n in the polyvinyl alcohol powder is more than or equal to 90.5%;
the preparation process of the copper-based powder metallurgy friction material with the high stable friction coefficient comprises the following steps:
step 1, reduction of copper powder and iron powder:
Copper powder and iron powder are respectively placed in a reduction furnace for reduction reaction;
Step 2, ball milling:
Respectively putting the copper powder and the iron powder which are qualified in reduction into a ball mill to perform ball milling for 0.5-1 h; copper powder = steel ball: iron powder = 10:1; the weight ratio is as follows;
step 3, drying:
Classifying graphite powder, molybdenum powder, silicon-chromium alloy and barium sulfate powder into an oven, and heating the oven to 120-150 ℃ for 3.0-6.0 h to remove water in the various powders;
The heating time of the oven is 30min;
Step 4, sieving:
sieving the dried ferrochrome alloy powder, graphite powder, barium sulfate and aluminum oxide powder respectively, and taking ferrochrome alloy powder of-200 meshes, graphite powder of +80 meshes, barium sulfate powder of-400 meshes and aluminum oxide powder of-100 meshes for standby;
step 5, batching and mixing:
Sequentially weighing electrolytic copper powder, reduced iron powder, graphite, ferrochrome, aluminum oxide, molybdenum powder, precipitated barium sulfate and polyvinyl alcohol powder according to the mass percentage, and mixing the weighed materials and mixed oil for 20-24 hours in a double-cone mixer with the war speed of 40-50 r/min; obtaining a mixture;
Step 6, pressing:
Weighing the obtained mixture according to the design requirement of the product, pouring the mixture into a mold, scraping and cold-pressing to form a plurality of pressed blanks of copper-based powder metallurgy friction materials with the density of 5.8-6.5 g/cm 3;
Step 7, sintering:
Respectively assembling the obtained pressed compact of each copper-based powder metallurgy friction material and the steel back into an assembly piece; loading the stacked assembly into a pressurized sintering furnace for sintering to obtain a copper-based powder metallurgy friction material;
During sintering, heating the pressurized sintering furnace to 120 ℃ at 5 ℃/min under the condition of introducing hydrogen or ammonia decomposition gas, and preserving heat for 1.5-2 h; after the heat preservation is finished, the temperature is increased to 700 ℃ at 2 ℃/min, and the heat preservation is carried out for 1.5 to 2 hours; continuously heating to the sintering temperature of 860-890 ℃ at 5 ℃/min, pressurizing to the sintering pressure of 0.5-0.7/MPa, and maintaining the pressure and the temperature for 3-5 h; after sintering, cooling the water to below 60 ℃ and releasing pressure, and discharging.
2. The copper-based powder metallurgy friction material with high stable friction coefficient according to claim 1, wherein the specific process is as follows: when the copper powder is subjected to reduction reaction, the reduction temperature is 380-450 ℃, and the heating rate is 150 ℃/h; when the iron powder is subjected to reduction reaction, the reduction temperature is 620-700 ℃, and the heating rate is 200 ℃/h; the heat preservation time of the reduction reaction of the copper powder and the iron powder is 2-3 h.
3. The copper-based powder metallurgy friction material having a high stable friction coefficient according to claim 1, wherein among the ball-milled steel balls, a large ball has a diameter of 96mm, a small ball has a diameter of 40mm, and a large ball to small ball=3:1, the ratio being weight ratio.
4. The copper-based powder metallurgy friction material with high stable friction coefficient according to claim 1, wherein the ratio of the sum of the ingredients to the mixed oil is 1:10; the proportion is weight ratio; wherein the weight unit of the ingredients is kg, and the weight unit of the mixed oil is ml.
5. The copper-based powder metallurgy friction material having a high stable friction coefficient according to claim 4 wherein the mixed oil is a mixture of gasoline and engine oil; the gasoline comprises the following components: engine oil = 1:1; the ratio is weight ratio.
6. The copper-based powder metallurgy friction material with a high stable friction coefficient according to claim 1, wherein the pressure born by a unit area of the iron-based powder metallurgy friction material compact in cold press molding is 500-600 MPa, and the dwell time is 10s.
7. The copper-based powder metallurgy friction material with high stable friction coefficient according to claim 1, wherein the copper-based powder metallurgy friction material has a hardness of 35 to 42HRF, an average friction coefficient of 0.31 to 0.34, a fluctuation range of friction coefficient of 3.03 to 4.61, and a wear rate of 0.0024 to 0.0038 mm/surface.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111510085.4A CN114210966B (en) | 2021-12-10 | 2021-12-10 | Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202111510085.4A CN114210966B (en) | 2021-12-10 | 2021-12-10 | Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114210966A CN114210966A (en) | 2022-03-22 |
| CN114210966B true CN114210966B (en) | 2024-08-20 |
Family
ID=80700911
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202111510085.4A Active CN114210966B (en) | 2021-12-10 | 2021-12-10 | Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114210966B (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN115126808A (en) * | 2022-03-31 | 2022-09-30 | 北京科技大学 | Copper-based powder metallurgy friction material suitable for high-speed braking and preparation method thereof |
| CN114833339B (en) * | 2022-05-06 | 2023-06-16 | 中国铁道科学研究院集团有限公司 | High-temperature-resistant powder metallurgy friction material, high-temperature-resistant brake pad, and preparation method and application thereof |
| CN116213712B (en) * | 2023-03-15 | 2024-10-25 | 西安航空制动科技有限公司 | Copper-based powder metallurgy friction material and friction disc preparation method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107245676A (en) * | 2016-11-21 | 2017-10-13 | 西安航空制动科技有限公司 | High-speed straight-line brake copper based powder metallurgy friction material and preparation method thereof |
Family Cites Families (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101576118B (en) * | 2009-06-15 | 2011-09-28 | 合肥工业大学 | Unleaded Cu-based sliding bearing material and preparation method thereof |
| CN109385586B (en) * | 2018-11-15 | 2020-07-10 | 北京科技大学 | Powder metallurgy friction material and preparation method of friction block |
| CN109469697B (en) * | 2018-12-05 | 2021-03-19 | 北京科技大学 | Fiber reinforced copper-based brake pad for high-speed train and preparation and friction braking performance thereof |
| CN110102754B (en) * | 2019-05-20 | 2020-04-24 | 中南大学 | Copper-based powder metallurgy friction material for dry clutch of heavy-duty vehicle and preparation method thereof |
| KR20210078165A (en) * | 2019-12-18 | 2021-06-28 | 재단법인 포항산업과학연구원 | Mixed powder for powder-sintered parts and method of fabricating powder-sintered parts |
| CN110976852B (en) * | 2020-01-14 | 2022-03-25 | 中国科学院兰州化学物理研究所 | Preparation method of copper-based graphite composite lubricating sealing material |
| CN113234954A (en) * | 2021-04-30 | 2021-08-10 | 中铁隆昌铁路器材有限公司 | Copper-based powder metallurgy friction material and preparation method thereof |
-
2021
- 2021-12-10 CN CN202111510085.4A patent/CN114210966B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107245676A (en) * | 2016-11-21 | 2017-10-13 | 西安航空制动科技有限公司 | High-speed straight-line brake copper based powder metallurgy friction material and preparation method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114210966A (en) | 2022-03-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN114210966B (en) | Copper-based powder metallurgy friction material with high stable friction coefficient and preparation method thereof | |
| CN107245676B (en) | High-speed straight-line brake copper based powder metallurgy friction material and preparation method thereof | |
| CN104399970B (en) | A kind of iron-based powder metallurgy friction material and preparation method thereof | |
| CN114210971B (en) | Copper-based powder metallurgy friction material for brake pads of motor train unit and preparation method of copper-based powder metallurgy friction material | |
| Asif et al. | Development of iron based brake friction material by hot powder preform forging technique used for medium to heavy duty applications | |
| CN102605209A (en) | Brake pad friction plate manufactured by powder metallurgy and used for high-speed train and preparation process of brake pad friction plate | |
| CN112899520B (en) | Powder metallurgy friction material and preparation method and application thereof | |
| CN1442257A (en) | Manufacturing method of high density iron base forging part | |
| CN104550902A (en) | Wet-type ferrum-based power metallurgy friction material and preparation method thereof | |
| CN109280792B (en) | Preparation method of BN/Cu composite material with low friction coefficient | |
| CN110242691A (en) | A kind of environmentally-friendly friction material and brake block and preparation method based on it | |
| CN109929511B (en) | Copper-free and antimony-free environment-friendly friction material, friction plate, preparation method and application | |
| CN114749658A (en) | Preparation method of composite rare earth element reinforced powder metallurgy friction material | |
| CN117448623B (en) | Copper-based composite friction material containing modified sepiolite, and preparation method and application thereof | |
| CN107299300A (en) | A kind of heavy load low abrasion copper base friction material and preparation method thereof | |
| CN104959608B (en) | A kind of nano silicon carbide granulate copper-base friction plate and preparation method thereof | |
| CN109780102A (en) | A kind of preparation method of motorbus graphene modified aluminas fibre reinforced composites brake block | |
| CN105983698A (en) | Powder forging method for forklift hub bearing | |
| CN116479284A (en) | High-energy high-power density wet copper-based friction material and preparation method thereof | |
| CN116219217A (en) | Graphene copper-based composite material, preparation method thereof and brake pad | |
| CN105908052A (en) | Cr2AlC-reinforced Fe-based composite and pressureless sintering preparation method thereof | |
| CN115740428A (en) | Powder metallurgy friction material and preparation method and application thereof | |
| CN113355563B (en) | Aluminum-boron nitride nanosheet layered composite material and preparation method thereof | |
| CN110005735A (en) | A kind of high-speed train braking friction block and preparation method thereof | |
| Ghazi et al. | Development and characterization of Fe-based friction material made by hot powder preform forging for low duty applications |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |