CN113801373B

CN113801373B - Friction filler, friction material composition, friction material and application thereof

Info

Publication number: CN113801373B
Application number: CN202111067058.4A
Authority: CN
Inventors: 张国文; 张静; 孙振龙; 陈德峰; 马运章; 赵春光; 吴智强
Original assignee: China Academy of Railway Sciences Corp Ltd CARS; Locomotive and Car Research Institute of CARS; Beijing Zongheng Electromechanical Technology Co Ltd; Tieke Aspect Tianjin Technology Development Co Ltd
Current assignee: China Academy of Railway Sciences Corp Ltd CARS; Locomotive and Car Research Institute of CARS; Beijing Zongheng Electromechanical Technology Co Ltd; Tieke Aspect Tianjin Technology Development Co Ltd
Priority date: 2021-09-13
Filing date: 2021-09-13
Publication date: 2023-09-01
Anticipated expiration: 2041-09-13
Also published as: CN113801373A

Abstract

The invention provides a friction filler, a friction material composition, a friction material and application thereof. The friction filler comprises: 14.6-18.1 parts of barium sulfate, 9.2-10.6 parts of crystalline flake graphite, 3.9-4.9 parts of metal scraps, 6.6-7.8 parts of reduced iron powder, 2.5-3.3 parts of zirconium dioxide, 3.3-4.8 parts of white corundum, 4.5-5.2 parts of cryolite, 0.47-0.63 part of chlorinated fatty acid and 3.8-4.7 parts of potassium feldspar. The invention also provides a friction material composition comprising a binder, reinforcing fibers and the friction filler described above. The invention further provides a friction material prepared from the friction material composition and application of the friction material in cleaning the tread of a railway vehicle. The friction material can effectively improve the adhesion coefficient between the wheel rails, play a role in repairing the wheels, prolong the whole service life of the wheels and improve the dynamic state between the wheel rails.

Description

Friction filler, friction material composition, friction material and application thereof

Technical Field

The invention relates to the technical field of cleaning friction of wheel treads of railway vehicles, in particular to a friction filler, a friction material composition, a friction material and application thereof, wherein the friction filler, the friction material composition and the friction material composition are suitable for cleaning the wheel treads.

Background

In the running process of the railway vehicle, the braking friction force and the traction friction force of the vehicle depend on the adhesion coefficient between the wheel rails, and the braking and traction design of the railway vehicle are based on the adhesion of the corresponding wheel rails, so that the wheels can be prevented from sliding and idling in the effective adhesion, and the probability of damage to the wheels and the steel rails is reduced. Due to the diversification of the operation environment, various pollutants exist between the wheels and the rails, and meanwhile, due to the fact that the sources of the pollutants are wide and complex, the adhesion coefficient between the wheels and the rails is reduced, so that the wheels possibly slide in the braking process and idle in the traction process, and the rails and the wheels are damaged. Meanwhile, due to the influence of wavy abrasion of the rails and the influence of irregularity of the rails, the tread is easy to be worn in a polygonal manner in the running process of the wheels, so that the dynamic state between the wheel rails is influenced, therefore, tread grinding materials are required to be developed and used for cleaning and grinding the surfaces of the wheels, the adhesion coefficient between the wheel rails can be effectively improved, the idling or sliding of the wheels is reduced, the wheel is modified, the whole service life of the wheels is prolonged, and the dynamic state between the wheel rails is improved. The existing tread cleaner grinding sub-material has the following problems in the use process: 1. metal inlays harmful to wheels are easy to occur in wet rain and snow environments; 2. part of the grinding sub-materials generate noise in the cleaning process due to the formula and raw materials; 3. the grinding sub-material is easy to generate thermal cracks in the frequent repeated braking process, so that the cracks are expanded to form grinding material falling blocks; 4. the grinding material has limited cleaning and repairing effects, and has poor effect of eliminating the polygonal outline on the surface of the wheel; 5. the abrasive materials have insufficient wear resistance.

Disclosure of Invention

In order to solve the above problems, an object of the present invention is to provide a friction material, a friction material composition, a friction material and applications thereof. The friction material is applied to cleaning of the tread of the wheels of the railway vehicle, can effectively improve the adhesion coefficient between the wheel rails, plays a role in repairing the wheels, prolongs the whole service life of the wheels and improves the dynamics state between the wheel rails.

In order to achieve the above object, the present invention provides a friction filler, wherein the friction filler comprises, in parts by mass: 14.6-18.1 parts of barium sulfate, 9.2-10.6 parts of crystalline flake graphite, 3.9-4.9 parts of copper scraps, 6.6-7.8 parts of reduced iron powder, 2.5-3.3 parts of zirconium dioxide, 3.3-4.8 parts of white corundum, 4.5-5.2 parts of cryolite, 0.47-0.63 part of chlorinated fatty acid and 3.8-4.7 parts of potassium feldspar.

In the friction filler, the chlorinated fatty acid is used as an extreme pressure additive containing active groups, can be decomposed at high temperature in the friction process, and the decomposed product can react with metal in the wheel to generate sulfide, phosphide and halide with lower shearing stress and melting point than the metal of the wheel, so that the contact is prevented from being closed, and a protective layer is formed on the surface of the wheel to avoid the generation of metal mosaic.

In the friction filler, the reduced iron powder and the metal scraps can synergistically improve the heat conductivity of the friction filler and avoid harmful heat influence on wheels in the cleaning process. The reduced iron powder is generally selected from reduced iron powder with 100-150 meshes. The iron content of the reduced iron powder is generally 99% or more.

In the friction filler described above, the metal chips may include copper chips, such as red copper chips. The metal shavings typically have a particle size of 40 mesh to 60 mesh, for example 40 mesh.

In the friction filler, the zirconium dioxide and the white corundum have good self-sharpening property, can play a role in modification in the friction process, and can effectively improve the cleaning capability. The zirconia may be selected from zirconia having a particle size of 300 mesh to 400 mesh, for example 325 mesh. The zirconia content of the zirconia is generally above 99%.

In the friction filler described above, the white corundum may have a particle size of 250 mesh to 350 mesh, for example 325 mesh. The alumina content in the white corundum is generally above 98%.

In the friction filler, the flake graphite can lubricate the tread of the wheel and reduce the abnormal abrasion of the surface of the wheel. The flake graphite may include L185 flake graphite or the like.

In the friction filler, the barium sulfate can improve the surface cleanliness of the wheel and has the effect of eliminating microcracks. The barium sulfate may be selected from barium sulfate having a particle size of 300 mesh to 400 mesh, for example 325 mesh.

In the friction filler, the potassium feldspar plays a role of cleaning particles. The potassium feldspar can be selected from potassium feldspar with the granularity of 250-350 meshes, such as 325 meshes.

Among the above friction fillers, cryolite having a particle size of 300 mesh to 400 mesh, for example, 325 mesh may be selected.

The invention also provides a friction material composition, wherein the friction material composition comprises 30.1-34.4% of adhesive, 11.8-14% of reinforcing fiber and the balance of the friction filler, wherein the total mass of the composition is 100%; wherein the binder comprises nitrile rubber and phenolic resin, and the reinforcing fibers comprise copper fibers.

In the friction material composition, the phenolic resin has higher thermal decomposition temperature, and the phenolic resin and the nitrile rubber can synergistically improve the toughness of the material after blending, blending and hot-press molding. The mass ratio of the nitrile rubber to the phenolic resin can be 7.5-9.6:22.6-24.8.

In the above friction material composition, the nitrile rubber may include nitrile rubber powder HLN40.

In the friction material composition described above, the phenolic resin generally comprises a boron modified phenolic resin. The boron modified phenolic resin can be selected from boron modified phenolic resin with particle size of 325 meshes.

In particular embodiments of the present invention, the boron modified phenolic resin described above generally has a cure time of 70s to 80s at 150 to 155 ℃.

In the friction material composition, the copper fibers have high thermal conductivity and strength, and the thermal conductivity of the friction material can be synergistically improved by matching metal scraps and reduced iron powder in the friction filler. Moreover, the copper fibers can also play roles in friction and cleaning of the wheels, and meanwhile, the wheels are not damaged. In a specific embodiment of the invention, the copper fibers generally have a length of 3mm to 5mm.

In particular embodiments of the present invention, the friction material composition may include, based on 100% total composition mass, 30.1% -34.4% binder, 11.8% -14% reinforcing fibers, 14.6% -18.1% barium sulfate, 9.2% -10.6% crystalline graphite, 3.9% -4.9% (e.g., 3.9% -4.8%) metal flake, 6.6% -7.8% (e.g., 6.6% -7.6%) reduced iron powder, 2.5% -3.3% (e.g., 2.5% -3.2%) zirconium dioxide, 3.8% -4.8% (e.g., 3.8% -4.3%) white corundum, 4.5% -5.2% cryolite, 0.47% -0.63% (e.g., 0.47% -0.62%) chlorinated fatty acid ester, 3.8% -4.7% potassium feldspar.

In particular embodiments of the present invention, the friction material composition may include, based on 100% total composition mass, 7.5% -9.6% nitrile rubber, 22.6% -24.8% phenolic resin, 11.8% -14% copper fiber, 14.6% -18.1% barium sulfate, 9.2% -10.6% crystalline graphite, 3.9% -4.9% copper dust, 6.6% -7.8% reduced iron powder, 2.5% -3.3% zirconium dioxide, 3.8% -4.8% white corundum, 4.5% -5.2% cryolite, 0.47% -0.63% chlorinated fatty acid ester, 3.8% -4.7% potassium feldspar.

In particular embodiments of the present invention, the friction material combination described above may further include a rubber vulcanization aid. The rubber vulcanization aid can adjust the vulcanization rate and the vulcanization degree of rubber, so as to adjust the overall vulcanization performance of the adhesive. The mass of the rubber vulcanization aid is generally determined according to the rubber usage amount, and can be 25% -40% of the mass of the nitrile rubber, for example.

In the above friction material composition, the rubber vulcanization aid generally includes accelerators CZ, stearic acid, zinc oxide, vulcanizing agents (e.g., sulfur, etc.). Preferably, the mass ratio of the accelerator CZ, the stearic acid, the zinc oxide and the vulcanizing agent is 1:1:1:1.

In particular embodiments of the present invention, the friction material composition may include a binder, reinforcing fibers, a friction filler, and a rubber vulcanization aid, wherein the friction material composition includes 7.5% -9.6% nitrile rubber, 22.6% -24.8% phenolic resin, 11.8% -14% copper fibers, 14.6% -18.1% barium sulfate, 9.2% -10.6% crystalline graphite, 3.9% -4.9% copper scraps, 6.6% -7.8% reduced iron powder, 2.5% -3.3% zirconium dioxide, 3.8% -4.8% white corundum, 4.5% -5.2% cryolite, 0.47% -0.63% chlorinated fatty acid ester, 3.8% -4.7% potassium feldspar, and 25% -40% rubber vulcanization aid by mass of nitrile rubber, based on 100% total mass of the binder, the reinforcing fibers, and the friction filler.

The invention also provides a friction material which is prepared from the friction material composition.

In a specific embodiment of the present invention, the friction material is prepared by a process generally comprising: and mixing the friction material composition at a high speed, adding a wetting agent, stirring uniformly, hot-press forming, and secondary curing to obtain the friction material.

In the preparation method of the friction material, the wetting agent is used for improving the uniformity degree of the mixed materials. The mass of the wetting agent is typically 1% of the total mass of the friction material composition. The wetting agent can be toluene, etc.

In the preparation method of the friction material, the stirring speed is generally controlled to be 50-60r/min, and the stirring time is generally controlled to be 35-45min.

In the preparation method of the friction material, the hot pressing temperature is generally controlled to be 155-165 ℃, the hot pressing time is generally controlled to be 30-40min, and the hot pressing pressure is generally controlled to be 25-35MPa.

In the above method for producing a friction material, the secondary curing is generally performed by a step temperature treatment to cure the stable material properties. The secondary curing stage may be, in order: the secondary curing is completed after heat preservation for 1h at 80 ℃, 0.5h at 100 ℃, 1h at 120 ℃, 1h at 140 ℃, 2h at 160 ℃ and 3h at 170 ℃.

In a specific embodiment of the present invention, the method for preparing a friction material may specifically include: placing the friction material composition into a mixer for high-speed mixing, simultaneously adding a wetting agent accounting for 1% of the total mass of the friction material composition for mixing to form a material, adopting the high-speed mixer to stir at a high speed of 50-60r/min for 35-45min, then placing the material into a die with the temperature raised to 160+/-5 ℃, hot-pressing for 30-40min on a hydraulic press at the temperature of 155-165 ℃ and the pressure of 25-30MPa, placing the material into an oven for secondary curing treatment after hot-press molding, namely, preserving the heat of 80 ℃ for 1h,100 ℃ for 0.5h,120 ℃ for 1h,140 ℃ for 1h,160 ℃ for 2h, and finally preserving the heat of 170 ℃ for 3h, thus obtaining the friction material.

The invention also provides application of the friction material in cleaning the tread of the railway vehicle. The friction material has higher wear resistance and mechanical strength when being applied to the tread cleaning process of the wheel, can effectively improve the adhesion and crack conditions of the wheel, repair the wheel and prolong the service life of the wheel.

The invention has the beneficial effects that:

1. the friction material provided by the invention can be applied to the tread cleaning process of the wheels, and the adhesion between the wheels and the steel rail can be improved by carrying out a film layer with the tread of the wheels; meanwhile, the material also has a grinding function, and can effectively eliminate tiny cracks on the surface of the wheel and out-of-roundness of the wheel, so that the service life of the wheel is prolonged; the static friction coefficient between the wheel surface and the steel rail is improved by friction, so that the adhesion coefficient calculated by traction and braking can be improved, and the damage of the wheel caused by slip and spin in rainy and snowy days can be reduced.

2. The friction material provided by the invention has better toughness matching, can avoid the generation of the conditions such as falling blocks and the like in the use process, and has better wear resistance. The friction material has good overall heat conductivity, and can avoid harmful heat influence on wheels in the cleaning process. The friction material can also effectively play a role in repairing in the friction process, obviously improve the cleaning capacity and the repairing capacity, and can form a protective layer on the surface of the wheel to avoid the generation of metal mosaic. The friction material disclosed by the invention does not contain toxic or heavy metal substances, is environment-friendly and pollution-free, and is wide in raw material source and simple in preparation method.

Detailed Description

The technical solution of the present invention will be described in detail below for a clearer understanding of technical features, objects and advantageous effects of the present invention, but should not be construed as limiting the scope of the present invention.

In the following examples, the national standards according to which the respective performance parameter measurement methods are based are specifically as follows: measuring the compression strength GB/T1041 plastic compression property; determination of impact Strength GB/T1043.1 impact Properties of Plastic simply supported beams part 1: non-instrumented impact testing; hardness GB/T3398.2 Plastic hardness determination part 2: rockwell hardness;

the friction cleaning performance test is carried out by referring to a static friction coefficient, abrasion loss and repair performance test by adopting a rail vehicle scaled friction brake test bed, and the test method is as follows:

A. and (3) testing the static friction coefficient, namely rubbing the surface of the wheel by adopting a grinding cleaning material sample block, wherein the original roughness Ra of the surface of the wheel is 0.3-0.4, and testing the static friction coefficient between the wheel rail sample blocks after friction cleaning. The friction cleaning speed is 100km/h, the cleaning pressure is 5KN, the braking is continued for 20s, the separation is carried out for 10s, the braking is repeated for 10 times, the static friction test pressure of the wheel track is 10KN, and the axle weight is calculated according to the axle weight of 16 tons.

B. And (3) the abrasion loss test, namely, according to the friction cleaning speed of 100km/h, the cleaning pressure of 5KN, the continuous braking of 20s and the separation of 10s, repeatedly cleaning for 100 times, calculating the abrasion loss of the abrasive subvolume, and indicating that the abrasion resistance of the cleaning abrasive material is higher as the abrasion loss is smaller.

C. And (3) the repair performance, namely, the greater the wheel mass loss is, the better the friction repair performance of the grinder is shown, wherein the repair performance is calculated by repeatedly cleaning 100 times according to the friction cleaning speed of 100km/h, the cleaning pressure of 5KN, the continuous braking of 20s and the separation of 10s and the front and rear mass loss of the wheel.

Key manufacturing and testing equipment: the model TM-II is a West Anshun general electromechanical technology institute; blendor, model W-200, rongde mechanical Co., ltd; hydraulic press, model 315 tons, south-through huge energy forging and pressing mechanical limited company. Curing oven, 250 ℃ at maximum, ningbo Hongshi electric heating oven Co., ltd. Hot press mold, zheng zhou tricyclic mold, has company limited.

Raw materials: base material: the phenolic resin particles are boron modified phenolic resin with the particle size of 325 meshes produced by Sumitomo electric Co., ltd, and the curing speed of the boron modified phenolic resin is 70-80 seconds at 155-150 ℃;

the nitrile rubber is nitrile rubber powder HLN40, and the manufacturer is Huang Shanhua blue family technology Co., ltd;

the reduced iron powder is primary reduced iron powder with 100-150 meshes, the iron content is more than 99 percent, and manufacturers are all Xin friction powder limited companies in Dayu city;

cryolite with particle size of 325 meshes and fluorine mass content of more than or equal to 50 percent is manufactured by Duxin friction powder Co., ltd in Dayu city;

the granularity of the zirconium dioxide is 325 meshes, wherein the content of the zirconium dioxide is more than 99 percent, and the manufacturer is Shenzhou abrasive limited company of spring yang;

the granularity of the white corundum is 325 meshes, the alumina content is more than 98 percent, and the manufacturer is Shenzhou abrasive material Co., spring yang;

the length of the red copper fiber is 3mm-5mm, the copper content is more than or equal to 99.5%, and the manufacturer is Shijiu Shuogong friction material science and technology Co., ltd;

the granularity of the copper scraps is 40 meshes, the copper content is more than or equal to 99.5%, and the manufacturer is Shijiu Shuogong friction material science and technology Co., ltd;

the granularity of the barium sulfate is 325 meshes, the content of the barium sulfate is more than 98 percent, and the manufacturer is Shijia concentrated chemical industry Co., ltd;

the flake graphite is L185, and the manufacturer is Zhao Guyao graphite ore;

potassium feldspar powder with 325 meshes and potassium oxide content of more than 7 percent is manufactured by Shijizhuang Xingxing industry Co.

The manufacturer of the chlorinated fatty acid ester is Zhengzhou samming chemical products limited company;

the promoters CZ, zinc oxide, stearic acid and sulfur are commercial products.

Comparative example 1

The comparative example provides a friction material, which is prepared by the following steps:

1. 500g of nitrile rubber powder, 1000g of phenolic resin powder, 600g of barium sulfate, 500g of crystalline flake graphite, 690g of copper fibers, 240g of copper scraps, 386g of reduced iron powder, 102g of zirconium dioxide, 150g of white corundum, 204g of cryolite, 30g of chlorinated fatty acid ester, 243g of potassium feldspar, 50g of zinc oxide, 50g of accelerator, 50g of stearic acid and 50g of sulfur are weighed.

2. Pouring the weighed raw materials into a produced double-cone high-speed mixer, simultaneously adding toluene with the mass being 1% of the total mass of the raw materials as a forming auxiliary agent, setting the rotating speed of the mixer to be 60 revolutions per minute, mixing for 35 minutes, and carrying out hot press forming on the formed mixture by using a 315 ton hydraulic press after uniform mixing, wherein the forming pressure is 30MPa, the hot press temperature is 160 ℃, and the hot press time is 35 minutes. After hot press molding, the hot press molded material was subjected to secondary curing by an oven according to the curing procedure shown in table 1 to obtain a friction material, which was used as a cleaning and polishing product.

TABLE 1

Sequence number	Curing temperature (. Degree. C.)	Time of thermal insulation (h)
			1	80	1
2	100	0.5
			3	120	1
4	140	1
			5	160	2
6	170	3

The friction material of comparative example 1 was subjected to performance test, and the results are shown in table 2.

TABLE 2

Comparative example 2

1. 300g of nitrile rubber powder, 1200g of phenolic resin powder, 950g of barium sulfate, 400g of crystalline graphite, 500g of copper fibers, 160g of copper scraps, 280g of reduced iron powder, 160g of zirconium dioxide, 250g of white corundum, 247g of cryolite, 18g of chlorinated fatty acid ester, 180g of potassium feldspar, 30g of zinc oxide, 30g of accelerator, 30g of stearic acid and 30g of sulfur.

2. Pouring the weighed raw materials into a produced double-cone high-speed mixer, simultaneously adding toluene with the mass being 1% of the total mass of the raw materials, setting the rotating speed of the mixer to be 60 revolutions per minute, mixing for 35 minutes, and carrying out hot press molding on the formed mixture by using a 315 ton hydraulic press after uniform mixing, wherein the molding pressure is 30MPa, the hot press temperature is 160 ℃, and the hot press time is 35 minutes. After hot press molding, the hot press molded material was subjected to secondary curing by an oven according to the curing procedure set in table 1 to obtain a friction material, which was used as a cleaning and polishing product.

The friction material of comparative example 2 was subjected to performance test, and the results are shown in table 3.

TABLE 3 Table 3

Example 1

The embodiment provides a friction material, and the preparation method comprises the following steps:

1. 350g of nitrile rubber powder, 1150g of phenolic resin powder, 840g of barium sulfate, 430g of crystalline flake graphite, 550g of copper fibers, 183g of copper scraps, 310g of reduced iron powder, 150g of zirconium dioxide, 200g of white corundum, 240g of cryolite, 22g of chlorinated fatty acid ester, 220g of potassium feldspar, 35g of zinc oxide, 35g of accelerator, 35g of stearic acid and 35g of sulfur.

2. Pouring the weighed raw materials into a produced double-cone high-speed mixer, simultaneously adding toluene with the mass accounting for 1% of the total mass of the raw materials, setting the rotating speed of the mixer to be 60 revolutions per minute, mixing for 35 minutes, and carrying out hot press molding on the obtained mixture by using a 315-ton hydraulic press after uniform mixing, wherein the molding pressure is 30MPa, the hot press temperature is 160 ℃, and the hot press time is 35 minutes. After hot press molding, the material after hot press molding is subjected to secondary curing by using an oven according to a set curing program to obtain the friction material, and the friction material can be used as a cleaning and grinding product.

The friction material of example 1 was subjected to performance testing, and the results are shown in table 4.

TABLE 4 Table 4

Example 2

1. 400g of nitrile rubber powder, 1100g of phenolic resin powder, 760g of barium sulfate, 460g of crystalline flake graphite, 600g of copper fibers, 201g of copper scraps, 330g of reduced iron powder, 120g of zirconium dioxide, 220g of white corundum, 230g of cryolite, 24g of chlorinated fatty acid ester, 200g of potassium feldspar, 40g of zinc oxide, 40g of accelerator, 40g of stearic acid and 40g of sulfur.

2. Pouring the weighed raw materials into a produced double-cone high-speed mixer, setting the rotation speed of the mixer to be 60 revolutions per minute, mixing for 35 minutes, and carrying out hot press molding on the mixture by using a 315 ton hydraulic press after uniform mixing, wherein the molding pressure is 30MPa, the hot press temperature is 160 ℃, and the hot press time is 35 minutes. After hot press molding, the material after hot press molding is subjected to secondary curing by using an oven according to a set curing program to obtain the friction material, and the friction material can be used as a cleaning and grinding product.

The friction material of example 2 was subjected to performance testing, and the results are shown in table 5.

TABLE 5

Example 3

1. 450g of nitrile rubber powder, 1050g of phenolic resin powder, 680g of barium sulfate, 490g of crystalline flake graphite, 650g of copper fibers, 226g of copper scraps, 360g of reduced iron powder, 140g of zirconium dioxide, 180g of white corundum, 210g of cryolite, 29g of chlorinated fatty acid ester, 180g of potassium feldspar, 45g of zinc oxide, 45g of accelerator, 45g of stearic acid and 45g of sulfur are weighed.

2. Pouring the weighed raw materials into a produced double-cone high-speed mixer, simultaneously adding toluene with the mass accounting for 1% of the total mass of the raw materials, setting the rotating speed of the mixer to be 60 revolutions per minute, mixing for 35 minutes, and carrying out hot press molding on the formed mixture by using a 315-ton hydraulic press after uniform mixing, wherein the molding pressure is 30MPa, the hot press temperature is 160 ℃, and the hot press time is 35 minutes. After hot press molding, the material after hot press molding is subjected to secondary curing by using an oven according to a set curing program to obtain the friction material, and the friction material can be used as a cleaning and grinding product.

The friction material of example 3 was subjected to performance testing, and the results are shown in table 6.

TABLE 6

The composition of the components and the results of the performance test of the friction materials prepared in comparative examples 1 to 2 and examples 1 to 3 are summarized in table 7.

TABLE 7

As can be seen from a comparison of the above test results, when the amount of each component in the friction material composition is too large or too small, the mechanical properties, wear resistance, and repair properties of the friction material to the wheel are significantly reduced. The friction material composition can realize tread cleaning function as a whole and improve adhesion and wheel out-of-roundness by selecting proper components and controlling the dosage of each component in proper ranges.

Claims

1. A friction filler, wherein the friction filler comprises, in parts by mass: 14.6-18.1 parts of barium sulfate, 9.2-10.6 parts of crystalline flake graphite, 3.9-4.9 parts of metal scraps, 6.6-7.8 parts of reduced iron powder, 2.5-3.3 parts of zirconium dioxide, 3.3-4.8 parts of white corundum, 4.5-5.2 parts of cryolite, 0.47-0.63 part of chlorinated fatty acid ester and 3.8-4.7 parts of potassium feldspar;

the metal scraps comprise copper scraps.

2. The friction filler according to claim 1, wherein the reduced iron powder has a particle size of 100 to 150 mesh;

the copper scraps comprise red copper scraps;

the granularity of the zirconium dioxide is 300-400 meshes;

the granularity of the white corundum is 250-350 meshes;

the granularity of the cryolite is 300-400 meshes;

the granularity of the barium sulfate is 300-400 meshes;

the granularity of the potassium feldspar is 250-350 meshes;

the flake graphite comprises L185 flake graphite.

3. The friction filler according to claim 2, wherein the metal shavings have a particle size of 40-60 mesh.

4. The friction filler according to claim 2, wherein the metal shavings have a particle size of 40 mesh.

5. The friction filler according to claim 2, wherein the particle size of the zirconium dioxide is 325 mesh.

6. A friction filler according to claim 2, wherein the white corundum has a particle size of 325 mesh.

7. The friction filler according to claim 2, wherein the cryolite has a particle size of 325 mesh.

8. The friction filler according to claim 2, wherein the particle size of the barium sulfate is 325 mesh.

9. The friction filler according to claim 2, wherein the potassium feldspar has a particle size of 325 mesh.

10. A friction material composition comprising 30.1 to 34.4% of a binder, 11.8 to 14% of reinforcing fibers, and the balance of the friction filler according to any one of claims 1 to 9, based on 100% of the total mass of the composition;

wherein the binder comprises nitrile rubber and phenolic resin, and the reinforcing fibers comprise copper fibers.

11. The friction material composition of claim 10, wherein the mass ratio of nitrile rubber to phenolic is 7.5-9.6:22.6-24.8.

12. The friction material composition of claim 11, wherein the nitrile rubber comprises nitrile rubber powder HLN40 and the phenolic resin comprises a boron modified phenolic resin.

13. The friction material composition of claim 12, wherein the boron modified phenolic resin has a particle size of 325 mesh and a cure time of 70s to 80s at 150 to 155 ℃.

14. The friction material composition of claim 10, wherein the copper fibers have a length of 3mm-5mm.

15. A friction material composition according to any one of claims 10 to 14, wherein the friction material composition comprises, based on 100% total composition mass, 30.1% to 34.4% binder, 11.8% to 14% reinforcing fibres, 14.6% to 18.1% barium sulphate, 9.2% to 10.6% crystalline graphite, 3.9% to 4.9% metal shavings, 6.6% to 7.8% reduced iron powder, 2.5% to 3.3% zirconium dioxide, 3.8% to 4.8% white corundum, 4.5% to 5.2% cryolite, 0.47% to 0.63% chlorinated fatty acid ester, 3.8% to 4.7% potassium feldspar.

16. The friction material composition according to claim 15, wherein the friction material composition comprises 7.5% -9.6% nitrile rubber, 22.6% -24.8% phenolic resin, 11.8% -14% copper fiber, 14.6% -18.1% barium sulfate, 9.2% -10.6% crystalline graphite, 3.9% -4.9% metal chips, 6.6% -7.8% reduced iron powder, 2.5% -3.3% zirconium dioxide, 3.8% -4.8% white corundum, 4.5% -5.2% cryolite, 0.47% -0.63% chlorinated fatty acid ester, 3.8% -4.7% potassium feldspar, based on 100% total mass of the composition.

17. The friction material composition of any one of claims 10-14, 16, wherein the friction material composition further comprises a rubber vulcanization aid, the mass of the rubber vulcanization aid being 25% -40% of the mass of the nitrile rubber.

18. The friction material composition of claim 17, wherein the rubber vulcanization aid comprises accelerators CZ, stearic acid, zinc oxide, vulcanizing agents.

19. The friction material composition of claim 18, wherein the mass ratio of promoter CZ, stearic acid, zinc oxide, vulcanizing agent is 1:1:1:1.

20. The friction material composition of claim 18, wherein the vulcanizing agent comprises sulfur.

21. The friction material composition of claim 15, wherein the friction material composition further comprises a rubber vulcanization aid, the mass of the rubber vulcanization aid being 25% -40% of the mass of the nitrile rubber.

22. The friction material composition of claim 21, wherein the rubber vulcanization aid comprises accelerators CZ, stearic acid, zinc oxide, vulcanizing agents.

23. The friction material composition of claim 22, wherein the mass ratio of promoter CZ, stearic acid, zinc oxide, vulcanizing agent is 1:1:1:1.

24. The friction material composition of claim 22, wherein the vulcanizing agent comprises sulfur.

25. A friction material made from the friction material composition of any one of claims 10-24.

26. Use of the friction material of claim 25 in tread cleaning of rail vehicles.