Rare earth lubricated high speed train brake pad and preparation method thereof

Abstract

The application discloses a rare earth lubricated high-speed train brake shoe and a preparation method thereof. The train brake shoe comprises mixed powders of iron and copper, mixed powders of flaky graphite and granular graphite, molybdenum disulfide, alumina fiber, high-carbon chromium iron powder, chromium powder and rare earth element powder. The prepared high-speed train brake shoe is prepared through a powder mixing, cold pressing forming and hot pressing sintering process, and has the advantages of low cost of raw material powder, avoidance of the dispersion problem caused by nano powder, promotion of the sintering densification process by the addition of rare earth elements, simple preparation process of the whole brake shoe material, easy scale production, and the like. The cooperative design of chromium and rare earth elements enables the brake shoe material to have the ability of self-adaptive adjustment with the change of braking conditions. The iron-copper-based brake shoe prepared by the method can be well matched with a carbon ceramic brake disc at 400km / h and above, and realizes stable and high friction coefficient and wear resistance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of producing high-speed grade train brake pads by powder metallurgy process, and particularly provides a rare earth lubricated high-speed train brake pad suitable for braking matched with carbon ceramic disc and a preparation method. BACKGROUND

[0002] The copper-based brake pad prepared by the powder metallurgy method has excellent friction and wear performance, good heat conduction and environmental adaptability when matched with a steel disc, and is one of the core key components in the braking system of 200-350km / h high-speed motor train unit. However, with the proposal of the CR450 Technology Innovation Project Implementation Plan of the State Railway Group in 2021, the operating speed of the new generation of "Revival" motor train unit CR450 under research will reach 400km / h. Taking the existing CRH380B motor train unit as an example, the braking energy consumed at 400km / h under emergency braking is 30% higher than that at 350km / h, which also brings great challenges to the braking system, mainly reflected in the high temperature between the friction interfaces caused by high kinetic energy conversion. The carbon ceramic (C / C-SiC) brake disc with low density, high strength, excellent fatigue resistance and stable high-temperature friction and wear performance becomes one of the important means to replace the traditional alloy steel brake disc for higher braking speed working conditions and light weight of the train braking system. However, compared with the alloy steel disc, the temperature rise of the friction interface is more significant when the carbon ceramic brake disc participates in braking. The existing copper-based brake pad maintains an average temperature of 700℃ or above at the friction interface for a long time when matched with the carbon ceramic disc at 400km / h, and the instantaneous temperature can reach 1000℃, close to the melting point (1083℃) of pure copper, which indicates that the high-temperature strength of the copper matrix restricts its further application on ≥350km / h high-speed trains, and it is urgent to develop a brake pad with superior high-temperature mechanical properties and friction and wear performance.

[0003] Currently, the common brake pad materials also include resin-based brake pads and iron-based brake pads. The resin-based brake pad material is not suitable for use under high-speed and heavy-load conditions because it uses organic resin as the matrix, which is mainly affected by the insufficient high-temperature strength of the matrix. For example, the thermal decomposition temperature of commercial phenolic resin is not more than 400 DEG C. The iron-based brake pad is low in price and has higher high-temperature strength, and is widely used in airplanes, tanks and other heavy-load special vehicles. The patent CN104399970B "Iron-based powder metallurgy friction material and preparation method thereof" is prepared by adding iron powder, copper powder, manganese powder, graphite powder, silicon carbide powder, molybdenum disulfide powder, silicon dioxide powder, aluminum oxide powder and precipitated barium sulfate powder, and is applied to the iron-based friction material under low speed. The patent CN106086718B "Clutch iron-based composite friction material and preparation method thereof" uses gray cast iron powder or nodular cast iron powder, wear-resistant powder, graphite powder and carbon fibers to prepare the iron-based friction material for the clutch. The patent CN112059171B develops a powder metallurgy brake pad matched with a carbon ceramic disc, mainly containing iron powder, copper powder, flaky graphite, graphene, ferrous sulfide powder, spherical chromium powder, molybdenum powder, chromium-iron alloy powder, molybdenum-iron alloy powder, silicon carbide and titanium dioxide. Because it needs to use spray bonding and shock pressure sintering, the preparation process is complex, the product cycle is long, and the cost is also increased. Based on the above, there is no invention of brake pad material specially for 400 km / h and above and matched with carbon ceramic disc. SUMMARY

[0004] In view of the above, the present application provides a rare earth lubricated high-speed train brake pad and a preparation method thereof. By adjusting the ratio of iron and copper, reasonably designing other components and introducing rare earth elements, a brake pad material that can be matched with a carbon ceramic brake disc, has excellent friction and wear performance at a brake speed of ≥400 km / h, and has a simple preparation process and is suitable for large-scale production is prepared.

[0005] A rare earth lubricated high-speed train brake pad and a preparation method thereof, comprising the following components:

[0006] Iron and copper mixed powder: 50-80 parts by weight; mixed powder of flaky graphite and granular graphite: 5-20 parts by weight; molybdenum disulfide powder: 0.5-5 parts by weight; aluminum oxide fiber: 0.5-5 parts by weight; high-carbon chromium iron powder: 1-10 parts by weight; chromium powder: 1-10 parts by weight; rare earth element: 0.1-1.5 parts by weight.

[0007] Further, the rare earth element is lanthanum or cerium, and is added in the form of iron lanthanum, iron cerium, copper lanthanum or copper cerium intermetallic powder, wherein the weight fraction of the rare earth element in the intermetallic powder is 15%-30%.

[0008] Further, the alumina fiber has an average diameter of 0.1-10 μm and an aspect ratio of 50-100.

[0009] Further, the mixed powder of flaky graphite and granular graphite has a flaky graphite particle size of 250-600 μm, a granular graphite particle size of 150-250 μm, and a flaky graphite to granular graphite ratio of 1:2-2:1.

[0010] Further, the mixed powder of iron and copper has an iron powder of atomized iron powder, copper-coated iron powder, or a mixture of the two in any ratio, a particle size of 38-80 μm, and a copper powder of electrolytic copper powder, a particle size of 38-80 μm.

[0011] Further, the mixed powder of iron and copper has an iron powder of atomized iron powder, copper-coated iron powder, or a mixture of the two in any ratio, a particle size of 38-80 μm, and a copper powder of electrolytic copper powder, a particle size of 38-80 μm.

[0012] Another object of the present application is to provide a preparation method of a rare earth lubricated high-speed train brake pad, comprising the following steps:

[0013] (1) The components designed above are weighed according to the weight parts, and then 1% of kerosene based on the weight of the powder is weighed and transferred into a double-cone type mixing barrel for mixing;

[0014] (2) The mixed powder is cold-pressed into a shape;

[0015] (3) The cold blank is sintered in a hot-pressing sintering furnace;

[0016] (4) The sintered product is taken out after cooling to below 100℃, and the pressure is kept unchanged during the cooling process.

[0017] Further, the rotating speed of the mixing cylinder in S1) is 50-100 rpm, and the mixing time is 4-6 h.

[0018] Further, the pressure in S2) is 300-600 MPa, and the pressure maintaining time is 60-90 s.

[0019] Further, the sintering process in S3) includes two steps of continuous low-temperature and high-temperature sintering. The low-temperature sintering temperature is 700-800℃, the holding time is 30-60 min, the high-temperature sintering temperature is 1000-1200℃, the holding time is 30-90 min, and the atmosphere is hydrogen-nitrogen mixed gas. During the whole sintering process, the pressure is 2-5 MPa.

[0020] Original explanation and beneficial effects:

[0021] The core requirement of the brake pad material matched with the carbon ceramic disc is that the friction interface can remain stable at a temperature of 1000℃, which requires the friction surface to have excellent strength and high temperature lubricity. To solve this problem, the application first improves the high temperature strength of the brake pad material by increasing the iron content in the matrix. However, iron is easily oxidized at high temperatures to form a high-hard and brittle friction oxide film, which will fatigue crack under continuous stress. The broken hard particles will cause abnormal damage to the friction surface. Therefore, a certain proportion of copper needs to be retained, which can play a role similar to a binder on the friction surface to promote the formability of the friction film. Flake graphite can play a lubricating role below 400℃, and the addition of molybdenum disulfide can further widen the lubricating temperature to 650℃; in order to further improve the matching effect of the brake pad material with the carbon ceramic disc at various braking speeds and the high temperature lubricating performance, rare earth elements cerium or lanthanum are introduced. In addition to purifying the structure and promoting sintering densification, the rare earth elements form rare earth oxides when exposed to the friction surface during the friction process. At low temperatures, rare earth oxides exhibit particle properties and can strengthen the friction film, while at high temperatures, they promote the generation of smooth and dense oxide films on the friction surface to produce high temperature lubricating properties and help prevent further contact and reaction between the metal and the surrounding environment, thereby minimizing wear and improving the friction braking performance of the brake pad material at high temperatures. In addition, chromium undergoes partial diffusion with iron during sintering, causing the porous nature of chromium particles. Under mild braking conditions, the porous chromium is less broken and plays a large particle role, while the rare earth oxides play a major strengthening role in the friction film; under extreme braking conditions, the porous chromium intensifies the broken chromium-rich nano-strengthening phase for the friction film, while the rare earth oxides exhibit high temperature lubrication.

[0022] The advantages of the application include: (1) the main raw materials are iron powder, copper powder and graphite powder, etc. low-cost powders, and the content of rare earth elements is low, so the cost of the entire brake pad raw materials is not high; (2) the dispersion problem caused by nano-powder is avoided, and the addition of rare earth elements also promotes the sintering densification process, which makes the preparation process of the entire brake pad material relatively simple, low in preparation cost and easy to mass produce; (3) the synergistic design of multiple components enables the brake pad material to have the ability to adaptively adjust with changes in braking conditions. The high strength and wide temperature range lubricating ability also enable the brake pad to have good matching with the carbon ceramic brake disc at 400km / h and above. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 A flowchart of the preparation method of a rare earth lubricated high-speed train brake pad according to the application.

[0024] Figure 2 A schematic diagram of the instantaneous friction coefficient curve of the brake pad prepared in Example 1 using the method of the application;

[0025] Figure 3 Schematic diagram of the instantaneous friction coefficient curve of the brake pad prepared by Example 2 of the method of the present invention;

[0026] Figure 4 Schematic diagram of the instantaneous friction coefficient curve of the brake pad prepared by Example 3 of the method of the present invention. DETAILED DESCRIPTION

[0027] The technical solution of the present invention will be further described below with reference to specific drawings and embodiments.

[0028] The present invention provides a rare earth lubricated high-speed train brake pad and a preparation method thereof. The weight proportions of the components of the high-speed train brake pad are as follows:

[0029] Mixed powder of iron and copper: 50-80 parts by weight; mixed powder of flake graphite and granular graphite: 5-20 parts by weight; molybdenum disulfide powder: 0.5-5 parts by weight; alumina fiber: 0.5-5 parts by weight; high carbon ferrochrome powder: 1-10 parts by weight; chromium powder: 1-10 parts by weight; rare earth elements: 0.1-1.5 parts by weight.

[0030] Furthermore, the rare earth element is lanthanum or cerium; it is added in the form of a master alloy powder, wherein the weight fraction of the rare earth element in the master alloy powder is 15%-30%;

[0031] The average diameter of the alumina fiber is 0.1-10 μm, and the aspect ratio is 50-100.

[0032] Furthermore, the particle size of the flake graphite in the mixed powder of flake graphite and granular graphite is 250-600 μm, and the particle size of the granular graphite is 150-250 μm; and the ratio of flake graphite to granular graphite is 1:2-2:1;

[0033] The iron powder in the mixed powder of iron and copper is atomized iron powder, copper-coated iron powder or a mixture of the two in any proportion, with a particle size of 38-80 μm; the copper powder is electrolytic copper powder, with a particle size of 38-80 μm;

[0034] The ratio of iron to copper is 1:1-5:1.

[0035] Furthermore, the intermediate alloy is iron-lanthanum, iron-cerium, copper-lanthanum or copper-cerium.

[0036] like Figure 1 As shown, the present invention provides a method for preparing the above-mentioned high-speed train brake pad, which specifically includes the following steps:

[0037] S1) Weigh each component according to the designed ratio, then weigh kerosene accounting for 1% of the weight of the powder, and transfer them into a double-cone mixing barrel for mixing;

[0038] S2) uniformly mixing the powder obtained in S1) and cold-pressing to obtain a cold compact;

[0039] S3) sintering the cold compact obtained in S2) at a certain temperature and pressure, and cooling to below 100°C after sintering to obtain the high-speed train brake pad.

[0040] Further, the rotating speed of the mixing cylinder in S1) is 50-100 rpm, and the mixing time is 4-6 h.

[0041] Further, the pressure of the cold-pressing in S2) is 300-600 MPa, and the pressure holding time is 60-90 s.

[0042] Further, the sintering process in S3) comprises continuous low-temperature and high-temperature sintering; wherein the temperature of the continuous low-temperature sintering is 700-800°C, and the holding time is 30-60 min; the temperature of the high-temperature sintering is 1000-1200°C, and the holding time is 30-90 min, the atmosphere is hydrogen-nitrogen mixed gas, and the pressure is 2-5 MPa.

[0043] Further, the density of the high-speed train brake pad obtained by the method is not less than 87.2%, the hardness is not less than 47.5 HRC, the compressive strength is not less than 246.5 MPa, and the shear strength is not less than 39.3 MPa.

[0044] Further, the friction coefficient of the high-speed train brake pad obtained by the method is not less than 0.3, the braking distance is not more than 7924 m, and the total wear is not more than 0.123 cm 3 / MJ under the emergency braking experiment at an initial speed of 400 km / h.

[0045] Example 1:

[0046] A rare earth reinforced and lubricated high-speed grade train brake pad comprises the following components:

[0047] mixed powder of iron and copper: 65 parts by weight; mixed powder of flaky graphite and granular graphite: 14 parts by weight; molybdenum disulfide powder: 3 parts by weight; alumina fiber: 2 parts by weight; high-carbon chromium iron powder: 8 parts by weight; chromium powder: 7 parts by weight; rare earth element: 1 part by weight.

[0048] The rare earth element is lanthanum, which is added in the form of copper-lanthanum intermediate alloy powder, wherein the weight fraction of the rare earth element in the intermediate alloy powder is 20%.

[0049] The average diameter of the alumina fiber is 5 μm, and the aspect ratio is 60.

[0050] The mixed powder of flaky graphite and granular graphite, the particle size of flaky graphite is 500 μm, the particle size of granular graphite is 230 μm, and the ratio of flaky graphite and granular graphite is 1:1.

[0051] The mixed powder of iron and copper, the iron powder is single atomized iron powder with a particle size of 75 μm, and the copper powder is electrolytic copper powder with a particle size of 45 μm. After the introduction of the intermediate alloy is included, the ratio of iron and copper is 1.5:1.

[0052] A preparation method of a rare earth reinforced and lubricated high-speed grade train brake pad, comprising the following steps:

[0053] S1) After the components designed above are weighed according to the weight parts, 1% of kerosene in the weight fraction of the powder is weighed and transferred into a double-cone type mixing barrel for mixing, the rotating speed is 70 r / min, and the mixing time is 5 h;

[0054] S2) The mixed powder is cold-pressed into a shape, the pressure is 400 MPa, and the pressure maintaining time is 70 s;

[0055] S3) The cold blank is sintered in a hydrogen-nitrogen mixed atmosphere in a hot-pressing sintering furnace, the low-temperature sintering temperature is 700 ℃, the temperature maintaining time is 50 min, the high-temperature sintering temperature is 1050 ℃, the temperature maintaining time is 70 min, the sintering pressure of the whole process is 3 MPa, and the sintered train brake pad is taken out after being cooled to below 100 ℃, and the pressure is kept unchanged during the cooling process. The instantaneous friction coefficient of the prepared train brake pad is shown in the following formula. Figure 2

[0056] Example 2:

[0057] A rare earth reinforced and lubricated high-speed grade train brake pad, comprising the following components:

[0058] The mixed powder of iron and copper: 70 weight parts; the mixed powder of flaky graphite and granular graphite: 12 weight parts; molybdenum disulfide powder: 2 weight parts; alumina fiber: 2 weight parts; high-carbon chromium iron powder: 8 weight parts; chromium powder: 5.2 weight parts; and rare earth element: 0.8 weight part.

[0059] The rare earth element is cerium, which is added in the form of copper-cerium intermediate alloy powder, wherein the weight fraction of the rare earth element in the intermediate alloy powder is 20%.

[0060] The alumina fiber has an average diameter of 4 μm and an aspect ratio of 70.

[0061] The mixed powder of flaky graphite and granular graphite, the particle size of flaky graphite is 600 μm, the particle size of granular graphite is 180 μm, and the ratio of flaky graphite and granular graphite is 1:1.5.

[0062] ​The mixed powder of iron and copper, the iron powder is single copper-coated iron powder with a particle size of 75 μm, and the copper powder is electrolytic copper powder with a particle size of 58 μm. After the introduction of the intermediate alloy is included, the ratio of iron to copper is 2.5:1.

[0063] A method for preparing a high-speed grade train brake pad reinforced and lubricated by rare earth elements, comprising the following steps:

[0064] S1) After the components designed above are weighed, 1% of kerosene by weight of the powder is weighed and transferred into a double-cone mixing barrel for mixing at a speed of 80 revolutions per minute for 5.5 hours;

[0065] S2) The mixed powder is cold-pressed into a shape at a pressure of 500 MPa for 80 seconds;

[0066] S3) The cold compact is sintered in a hydrogen-nitrogen mixed atmosphere in a hot-pressing sintering furnace at a low-temperature sintering temperature of 750 ℃ for 55 minutes and at a high-temperature sintering temperature of 1100 ℃ for 80 minutes, the whole process being carried out at a sintering pressure of 4 MPa, and the sintered product is taken out after cooling to below 100 ℃, the pressure being kept unchanged during the cooling process, so that a train brake pad is prepared, the instantaneous friction coefficient of which is shown in Figure 3

[0067] Example 3:

[0068] A high-speed grade train brake pad reinforced and lubricated by rare earth elements, comprising the following components:

[0069] Mixed powder of iron and copper: 60 parts by weight; mixed powder of flaky graphite and granular graphite: 17 parts by weight; molybdenum disulfide powder: 2 parts by weight; alumina fiber: 3 parts by weight; high-carbon chromium iron powder: 10 parts by weight; chromium powder: 6.5 parts by weight; rare earth element: 1.5 parts by weight.

[0070] The rare earth element is cerium, which is added in the form of an iron-cerium intermediate alloy powder, wherein the weight fraction of the rare earth element in the intermediate alloy powder is 20%.

[0071] The alumina fiber has an average diameter of 3 μm and an aspect ratio of 80.

[0072] The mixed powder of flaky graphite and granular graphite has a flaky graphite particle size of 300 μm and a granular graphite particle size of 150 μm, and the ratio of flaky graphite to granular graphite is 2:1.

[0073] The mixed powder of iron and copper, the iron powder is a mixture of atomized iron powder and copper-coated iron powder, the atomized iron powder having a weight ratio of 50% and a particle size of 62 μm, and the copper powder is electrolytic copper powder with a particle size of 38 μm.

[0074] ​The ratio of iron and copper is 4:1 after the introduction of the intermediate alloy.

[0075] A preparation method of a rare earth reinforced and lubricated high-speed grade train brake pad, comprising the following steps:

[0076] S1) After weighing the components designed above according to the weight parts, 1% of kerosene based on the weight fraction of the powder is weighed and transferred into a double-cone mixing barrel for mixing, the rotating speed of the mixing cylinder is 90 rpm, and the mixing time is 6 h;

[0077] S2) The uniformly mixed powder is cold-pressed into a shape, the pressure is 550 MPa, and the pressure maintaining time is 90 s;

[0078] S3) The cold blank is sintered in a hot-pressing sintering furnace, the low-temperature sintering temperature is 780 DEG C, the holding time is 40 min, the high-temperature sintering temperature is 1100 DEG C, the holding time is 65 min, and the atmosphere is hydrogen-nitrogen mixed gas. During the whole sintering process, the pressure is 2.5 MPa cold, and the temperature is below 100 DEG C. The instantaneous friction coefficient of the prepared train brake pad is shown in the following formula (1). Figure 4

[0079] The physical properties of the materials prepared in the above examples are shown in Table 1.

[0080] Table 1 shows part of the physical property parameters of the brake pads of Examples 1-3 and Comparative Example 1.

[0081]

[0082] The initial speed of the emergency braking experiment on the 1:1 brake bench is 400 km / h, the friction coefficient and the wear amount are shown in Table 2.

[0083] Table 2 shows the average friction coefficient, braking distance and wear amount of the brake pads of Examples 1-3 and Comparative Example 1.

[0084]

[0085] From Table 2 and Figure 1 It can be seen that in the case of continuous high-speed emergency braking, the friction coefficient of the materials of Examples 1-3 can be maintained at 0.3 or more, which has a relatively high and stable friction coefficient and a low wear amount. It shows that the rationality and practicability of the application of rare earth elements.

[0086] ​The rare earth lubricated high-speed train brake pad and the preparation method thereof provided by the embodiments of the present application are described in detail above. The above description of the embodiments is only used to help understand the method of the present application and its core idea; meanwhile, for those skilled in the art, according to the idea of the present application, the specific implementation and application range can be changed, and the above description should not be understood as a limitation on the present application.

[0087] As used in the specification and claims, certain terminology is used to describe certain components. Those of ordinary skill in the art will understand that different manufacturers of hardware can refer to the same component using different names. The specification and claims should not be controlled based on differences in naming alone, but rather on the difference in functionality of the components. As used throughout the specification and claims, "comprise" or "comprising" is an open term that should be interpreted as "comprising but not limited to." "Approximately" means within an acceptable error range for the corresponding function, and those skilled in the art can solve the technical problems within a certain error range and substantially achieve the technical effects. The subsequent description of the specification is a preferred embodiment for implementing the present application, and the description is for the purpose of illustrating the general principles of the present application, and is not intended to limit the scope of the present application. The scope of protection of the present application is defined by the appended claims.

[0088] It should also be noted that the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusion, so that a product or system including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such product or system. Without more limitations, the element defined by the phrase "comprising a" does not exclude the presence of additional identical elements in the product or system comprising the element.

[0089] It should be understood that the term "and / or" used herein is only a description of the association relationship of the associated objects, which means that there can be three relationships, for example, A and / or B, which means that there are three cases of A alone, A and B together, and B alone. In addition, the character " / " in this paper generally represents that the front and rear associated objects are a "or" relationship.

[0090] The above description shows and describes several preferred embodiments of the present application, but as mentioned above, it should be understood that the present application is not limited to the form disclosed herein, and should not be regarded as excluding other embodiments, but can be used in various other combinations, modifications and environments, and can be modified by the above teaching or related art or knowledge within the scope of the application conceived. The changes and modifications made by those skilled in the art without departing from the spirit and scope of the present application shall be within the scope of protection of the appended claims of the present application.

Claims

1. A method for preparing a high-speed train brake pad, characterized in that: The method specifically comprises the following steps: S1) Weigh each component according to the designed ratio, then weigh kerosene accounting for 1% of the weight of the powder, and transfer the mixture into a double-cone mixing barrel for mixing to obtain a mixed powder; The weight parts of the various components are: Mixed powder of iron and copper: 50-80 parts by weight; mixed powder of flake graphite and granular graphite: 5-20 parts by weight; molybdenum disulfide powder: 0.5-5 parts by weight; alumina fiber: 0.5-5 parts by weight; high-carbon ferrochrome powder: 1-10 parts by weight; chromium powder: 1-10 parts by weight; rare earth elements: 0.1-1.5 parts by weight; The rare earth element is lanthanum or cerium; it is added in the form of master alloy powder, wherein the weight fraction of the rare earth element in the master alloy powder is 15%-30%; The average diameter of the alumina fiber is 0.1-10 μm, and the aspect ratio is 50-100; The mixed powder of flake graphite and granular graphite has a particle size of 250-600 μm and a particle size of granular graphite of 150-250 μm; and the ratio of flake graphite to granular graphite is 1:2-2:1; The iron powder in the mixed powder of iron and copper is atomized iron powder, copper-coated iron powder or a mixture of the two in any proportion, with a particle size of 38-80 μm; the copper powder is electrolytic copper powder, with a particle size of 38-80 μm; The ratio of iron to copper is 1:1-5:1; S2) cold pressing the mixed powder obtained in S1) to obtain a cold blank; S3) sintering the cold blank obtained in S2) at a certain temperature and pressure, cooling it to below 100° C. after sintering, and taking it out to obtain a high-speed train brake pad.

2. The method according to claim 1, characterized in that The intermediate alloy in S1) is iron-lanthanum, iron-cerium, copper-lanthanum or copper-cerium.

3. The method according to claim 1, characterized in that The rotation speed of the mixing barrel in S1) is 50-100 rpm, and the mixing time is 4-6 hours.

4. The method according to claim 1, wherein The cold forming pressure in S2) is 300-600 MPa, and the holding time is 60-90 s.

5. The method according to claim 1, wherein The sintering process in S3) includes continuous low-temperature and high-temperature sintering; wherein the continuous low-temperature sintering temperature is 700-800°C, and the heat preservation time is 30-60 minutes; the high-temperature sintering temperature is 1000-1200°C, and the heat preservation time is 30-90 minutes, the atmosphere is a hydrogen and nitrogen mixed gas, and the pressure is 2-5MPa.

6. The method according to claim 1, characterized in that The high-speed train brake pad obtained by the method has a density of not less than 87.2%, a hardness of not less than 47.5 HRC, a compressive strength of not less than 246.5 MPa, and a shear strength of not less than 39.3 MPa.

7. The method according to claim 1, characterized in that The method obtained that the friction coefficient of the high-speed train brake pad is not less than 0.3, the braking distance is not greater than 7924m, and the total wear is not greater than 0.123cm in the emergency braking test at an initial speed of 400 km / h. 3 / MJ.

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