Carbon-copper composite material for pantograph slide plate and preparation method thereof

Abstract

The application discloses a carbon-copper composite material for a pantograph slide plate and a preparation method thereof. The carbon-copper composite material is prepared from the following components in percentage by mass: copper powder 65-68%, chromium powder 3-5%, tin powder 1-3%, titanium powder 1-3%, ultra-fine particle size calcined coke 10-13%, carbon fiber powder 9-11% and polysilazane resin 3-5%. The product prepared by the application has good self-lubricity and low resistivity, has good compressive strength, can maintain a long service life in a salt spray area environment, and has good economic prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pantograph, in particular to a carbon-copper composite material for pantograph slide plate and a preparation method thereof. BACKGROUND

[0002] The pantograph slide plate is a core conducting component for electric locomotive, high-speed rail and subway train to obtain power from overhead contact network. The pantograph slide plate needs to work under the combined conditions of dynamic sliding friction and large current transmission, and needs to have conductivity, mechanical strength and wear resistance.

[0003] The current pantograph slide plate still faces some problems, such as serious salt spray corrosion in coastal areas, which can cause loss of service life of the pantograph slide plate, leading to frequent replacement of the pantograph slide plate, further leading to economic loss.

[0004] Therefore, the present application is proposed to solve the technical problem. SUMMARY

[0005] The present application provides a carbon-copper composite material for pantograph slide plate and a preparation method thereof to solve the problem of low service life of the existing pantograph slide plate material in a humid environment.

[0006] The technical solution of the present application to solve the above technical problem is as follows:

[0007] The present application first provides a carbon-copper composite material for pantograph slide plate, which is composed of the following components by mass percentage: copper powder 65-68%, chromium powder 3-5%, tin powder 1-3%, titanium powder 1-3%, ultra-fine particle size calcined coke 10-13%, carbon fiber powder 9-11%, and polysilazane resin 3-5%.

[0008] Preferably, the fineness of the ultra-fine particle size calcined coke is 500-600 mesh, the fineness of the copper powder is 300-400 mesh, and the fineness of the carbon fiber powder is 200-300 mesh.

[0009] The present application further provides a preparation method of the carbon-copper composite material for pantograph, comprising the following steps:

[0010] S1, a carbon-copper composite material for pantograph slide plate according to claims 1-2 is weighed;

[0011] S2, the copper powder is cooled to room temperature after being reduced at a reduction temperature of 400-450℃ under the protection of ammonia decomposition gas for 3 hours, and the reduced copper powder is treated by ball milling and sieving through a standard sieve of corresponding particle size;

[0012] S3, the ultra-fine particle size calcined coke, carbon fiber powder, copper powder, chromium powder, tin powder, titanium powder is added into the V-type mixer in order of particle size from large to small, the mixing time is 1-2h, and the mixed powder I is prepared;

[0013] S4, the mixed powder I and polysilazane resin are poured into a double shaft kneader for kneading, the kneading time is 30-60min, and the mixed material II is prepared;

[0014] S5, the above mixed material II is placed in a hydraulic press, pre-pressed and exhausted at 50-80MPa, then slowly pressed to the target pressure to form a green body, and then, the pressure is quickly released and the green body is slowly demolded;

[0015] S6, the green body is pressed by isostatic pressing, wherein the pressure is 150-200MPa;

[0016] S7, the green body is placed in a sintering furnace with a nitrogen atmosphere, and the sintering temperature is 1300℃, and the carbon-copper composite material for a pantograph is prepared.

[0017] Preferably, in the step S3, the rotating speed of the mixer is 20-30rpm.

[0018] Preferably, in the step S4, the rotating speed of the kneader is 50-60rpm, and the kneading temperature is 150-200℃.

[0019] Preferably, in the step S5, the target pressure is 100-150MPa, the pressure holding time is 10-15min, and the pressing speed is 0.5-1.0mm / s.

[0020] Preferably, in the step S6, the sintering temperature is increased to 600℃ at a heating rate of 5℃ / h, and the temperature is kept for 1-2h, then the temperature is increased to 1300℃ at a heating rate of 2℃ / h, and the temperature is kept for 10-15h.

[0021] The beneficial effects of the present application are:

[0022] In the present application, small particle size raw materials are put into the mixer in order of particle size from large to small, and the density of the mixture is increased by pressing-sintering-secondary compression, and the porosity is reduced, which helps to improve the mechanical strength. After high-temperature sintering, the ultra-fine particle size calcined coke is converted from disordered carbon structure to graphite microcrystalline structure, the porosity is reduced, the volume shrinks, and the conductive network is connected. The chromium, tin and titanium powders can improve the bonding strength of the whole material, make the performance more optimal, and make the combination more compact. The polysilazane resin is added as an adhesive, and SiCN ceramic material is generated under high-temperature sintering, which improves the hardness of the material and can delay salt spray corrosion to protect the substrate material. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application are clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the present application.

[0024] Embodiment 1

[0025] The carbon-copper composite material for a pantograph provided in this embodiment is composed of the following components in terms of mass percentage: copper powder 65%, chromium powder 5%, tin powder 3%, titanium powder 3%, ultra-fine particle size calcined coke 10%, carbon fiber powder 9%, and polysilazane resin 5%.

[0026] The preparation method of the carbon-copper composite material for a pantograph provided in this embodiment includes the following steps:

[0027] S1, a carbon-copper composite material for a pantograph slide rail as claimed in claims 1-2 is weighed;

[0028] S2, the copper powder is reduced at a reduction temperature of 400℃ under the protection of ammonia decomposition gas, and after heat preservation for 3 hours, it is air-cooled to room temperature. The reduced copper powder is treated by ball milling and sieving with a standard sieve of corresponding particle size;

[0029] S3, ultra-fine particle size calcined coke with fineness of 500 mesh, copper powder with fineness of 300 mesh, chromium powder, tin powder, titanium powder, and carbon fiber powder with fineness of 200 mesh are weighed according to the proportioning amount, and are sequentially added to a V-type mixer according to the particle size from large to small. The rotation speed of the mixer is adjusted to 20 rpm, and the mixing time is 2 hours to obtain mixed powder one;

[0030] S4, the mixed powder one and the polysilazane resin are poured into a double-shaft kneading machine for kneading. The rotation speed of the kneading machine is set to 50 rpm, the kneading time is 60 minutes, and the kneading temperature is 150℃ to obtain mixed material two;

[0031] S5, the above-mentioned mixed material two is placed in a hydraulic press. First, pre-pressing and degassing are performed at 50 MPa, and then the pressure is increased to 150 MPa at a slow speed of 0.5 mm / s to press the green body. The pressure is maintained for 10 minutes, and then the pressure is quickly released and the green body is slowly demolded;

[0032] S6, the above-mentioned green body is re-pressed by isostatic pressing, and the pressure is 150 MPa;

[0033] S7, the above-mentioned green body is placed in a sintering furnace with a nitrogen atmosphere, and the temperature is increased to 600℃ at a heating rate of 5℃ / h, and the temperature is maintained for 1 hour. Then the temperature is increased to 1300℃ at a heating rate of 2℃ / h, and the temperature is maintained for 15 hours to obtain the carbon-copper composite material for a pantograph.

[0034] Embodiment 2

[0035] The carbon-copper composite material for a pantograph provided in the embodiment is composed of the following components in terms of mass percentage: copper powder 68%, chromium powder 3%, tin powder 1%, titanium powder 1%, ultra-fine particle size calcined coke 13%, carbon fiber powder 11%, and polysilazane resin 3%.

[0036] The preparation method of the carbon-copper composite material for a pantograph provided in the embodiment comprises the following steps:

[0037] S1, a carbon-copper composite material for a pantograph slide rail as claimed in claims 1-2 is weighed;

[0038] S2, the copper powder is reduced at a reduction temperature of 450°C under the protection of ammonia decomposition gas, and after heat preservation for 3 hours, it is air-cooled to room temperature. The reduced copper powder is treated by ball milling and sieving with a standard sieve of corresponding particle size;

[0039] S3, ultra-fine particle size calcined coke with fineness of 600 mesh, copper powder with fineness of 400 mesh, chromium powder, tin powder, titanium powder, and carbon fiber powder with fineness of 300 mesh are weighed according to the proportioning amount, and are sequentially added into a V-type mixer according to the particle size from large to small. The rotation speed of the mixer is adjusted to 30 rpm, and the mixing time is 1 h to obtain a mixed powder one;

[0040] S4, the mixed powder one and the polysilazane resin are poured into a double-shaft kneading machine for kneading. The rotation speed of the kneading machine is set to 60 rpm, the kneading time is 30 min, and the kneading temperature is 200°C to obtain a mixed material two;

[0041] S5, the above-mentioned mixed material two is placed in a hydraulic press. First, pre-pressing and exhaust are performed at 80 MPa, and then the pressure is increased to 100 MPa. The green body is pressed at a slow speed of 1.0 mm / s, pressure maintaining for 15 min, and then rapid pressure relief and slow demolding;

[0042] S6, the above-mentioned green body is re-pressed by isostatic pressing forming, wherein the pressure is 200 MPa;

[0043] S7, the above-mentioned green body is placed in a sintering furnace with nitrogen atmosphere, and heated to 600°C at a heating rate of 5°C / h, and heat preserved for 2 h. Then, the temperature is increased to 1300°C at a heating rate of 2°C / h, and heat preserved for 10 h to obtain a carbon-copper composite material for a pantograph slide rail.

[0044] Example 3

[0045] The carbon-copper composite material for a pantograph provided in the embodiment is composed of the following components in terms of mass percentage: copper powder 66%, chromium powder 4%, tin powder 2%, titanium powder 2%, ultra-fine particle size calcined coke 12%, carbon fiber powder 10%, and polysilazane resin 4%.

[0046] The embodiment provides a preparation method of the carbon-copper composite material for a pantograph, and comprises the following steps:

[0047] S1, a carbon-copper composite material for a pantograph slide rail is weighed according to claims 1-2;

[0048] S2, copper powder is reduced at a reduction temperature of 425 DEG C under protection of ammonia decomposition gas, and is air-cooled to room temperature after heat preservation for 3 hours; the reduced copper powder is subjected to ball milling and sieving treatment through a standard sieve with a corresponding particle size;

[0049] S3, superfine particle size calcined coke with fineness of 600 mesh, copper powder with fineness of 400 mesh, chromium powder, tin powder, titanium powder and carbon fiber powder with fineness of 300 mesh are weighed according to a proportioning amount respectively, and are sequentially added into a V-shaped mixer according to particle size from large to small; the rotation speed of the mixer is adjusted to 25 rpm, and the mixing time is 1.5 h, so that mixed powder I is prepared;

[0050] S4, mixed powder I and polysilazane resin are poured into a double-shaft kneader for kneading; the rotation speed of the kneader is set to 55 rpm, the kneading time is 45 min, and the kneading temperature is 180 DEG C, so that mixed material II is prepared;

[0051] S5, the above mixed material II is placed in a hydraulic press, is pre-pressed and degassed at 65 MPa, is pressed at a pressure of 120 MPa at a slow speed of 0.8 mm / s to form a green body, is kept for 12 min, and then is rapidly released and slowly demolded;

[0052] S6, the above green body is re-pressed by using an isostatic pressing forming mode, wherein the pressure is 170 MPa;

[0053] S7, the above green body is placed in a sintering furnace with a nitrogen atmosphere, is heated to 600 DEG C at a heating rate of 5 DEG C / h, is kept for 1.5 h, is then heated to 1300 DEG C at a heating rate of 2 DEG C / h, and is kept for 13 h, so that the carbon-copper composite material for a pantograph slide rail is prepared.

[0054] Comparative example 1

[0055] The difference from example 3 is that the chromium powder, the tin powder and the titanium powder are replaced by copper powder with an equal mass fraction, and the preparation method is basically the same as that of example 3.

[0056] Comparative example 2

[0057] The difference from example 3 is that the carbon fiber powder is replaced by ordinary carbon powder, and the preparation method is basically the same as that of example 3.

[0058] Comparative example 3

[0059] The difference from example 3 is that the polysilazane resin is replaced by coal tar pitch, and the preparation method is basically the same as that of example 3.

[0060] Experimental Example 1

[0061] The carbon-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were respectively subjected to performance tests on the abrasion test bench, and the railway industry standard TB / T 1842.1-2002 was used as a comparison. The experimental data results are shown in Table 1 below:

[0062] Table 1

[0063]

[0064] From the above tests, it can be seen that the data of the examples are improved compared with the comparative examples. This is because chromium forms solid solution strengthening in the copper matrix, improves the hardness and strength of the matrix, and can generate high-hardness chromium carbide to resist sliding wear; the melting point of tin is low, which produces a liquid phase during sintering of powder metallurgy, promotes particle rearrangement and pore filling, and improves material density; titanium is a strong carbide-forming element that pins grain boundaries to hinder grain growth, improving strength and toughness, and can improve the wettability of the metal and ceramic interface to improve material performance.

[0065] Experimental Example 2

[0066] The carbon-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were respectively subjected to salt spray corrosion resistance performance tests, and the carbon-copper composite materials for pantographs were subjected to neutral salt spray tests (NSS) according to the national standard GB / T 10125-2021. The test time was 720h, then the pantograph slide weight abrasion ratio g / ten thousand vehicle kilometers was tested on the abrasion test bench, and the performance degradation rate was calculated according to the following formula. The experimental data results are shown in Table 2 below:

[0067] Performance degradation rate = (weight abrasion ratio after salt spray resistance - weight abrasion ratio before salt spray resistance) / weight abrasion ratio before salt spray resistance * 100%.

[0068] Table 2

[0069]

[0070] From the above tests, it can be seen that in the comparative examples, the polysilazane resin is replaced, and there is no SiCN ceramic material generated, which greatly reduces the mechanical properties and salt spray resistance of the pantograph slide material. At the same time, the addition of polysilazane resin can improve the electrical conductivity of the material; in Comparative Example 2, the carbon fiber is replaced by ordinary carbon powder, which also results in a decrease in strength.

[0071] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, and any person skilled in the art, according to the technical solution and inventive concept of the present application, makes equivalent replacement or change within the technical range disclosed by the present application, which should be covered within the protection scope of the present application.

Claims

1. A carbon-copper composite material for a pantograph slide, characterized by, The carbon copper composite material for the pantograph slide rail is prepared from the following components by mass percentage: copper powder 65-68%, chromium powder 3-5%, tin powder 1-3%, titanium powder 1-3%, ultra-fine particle size calcined coke 10-13%, carbon fiber powder 9-11%, and polysilazane resin 3-5%; wherein the fineness of the ultra-fine particle size calcined coke is 500-600 mesh, the fineness of the copper powder is 300-400 mesh, and the fineness of the carbon fiber powder is 200-300 mesh.

2. A method for preparing carbon-copper composite material for pantograph slide, characterized in that, The method comprises the following steps: S1, weighing a carbon copper composite material for a pantograph slide rail according to claim 1; S2, reducing the copper powder at a reduction temperature of 400-450℃ under the protection of ammonia decomposition gas, and then air cooling to room temperature after heat preservation for 3 hours; the reduced copper powder is treated by ball milling and sieving through a standard sieve with a corresponding particle size; S3, adding the ultra-fine particle size calcined coke, carbon fiber powder, copper powder, chromium powder, tin powder, and titanium powder into a V-shaped mixer in order of decreasing particle size, and mixing for 1-2 hours to obtain a mixed powder I; S4, pouring the mixed powder I and polysilazane resin into a double-shaft kneader for kneading for 30-60 minutes to obtain a mixed material II; S5, taking the mixed material II and placing it in a hydraulic press, pre-pressing and exhausting at 50-80 MPa, then slowly pressing to a target pressure to form a green body, and then rapidly unloading and slowly demolding; S6, pressing the green body by isostatic pressing, wherein the pressure is 150-200 MPa; S7, placing the green body in a sintering furnace with a nitrogen atmosphere, and baking at a temperature of 1300℃ to obtain a carbon copper composite material for a pantograph.

3. The method for preparing a carbon-copper composite material for a pantograph sliding plate according to claim 2, characterized in that, In the step S3, the rotating speed of the mixer is 20-30 rpm.

4. The method for preparing a carbon-copper composite material for a pantograph sliding plate according to claim 2, characterized in that, In the step S4, the rotating speed of the kneader is 50-60 rpm, and the kneading temperature is 150-200℃.

5. The method for preparing a carbon-copper composite material for a pantograph sliding plate according to claim 2, characterized in that, In the step S5, the target pressure is 100-150 MPa, the pressure maintaining time is 10-15 minutes, and the pressing speed is 0.5-1.0 mm / s.

6. The method for preparing a carbon-copper composite material for a pantograph sliding plate according to claim 2, characterized in that, In the step S7, the sintering temperature is increased to 600℃ at a rate of 5℃ / h, and then increased to 1300℃ at a rate of 2℃ / h, and the temperature is maintained for 10-15 hours.

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