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

Abstract

The invention discloses a carbon-copper composite material for a pantograph slide plate and a preparation method of the carbon-copper composite material. The carbon-copper composite material is prepared from the following components in percentage by mass: 65-68% of copper powder, 3-5% of chromium powder, 1-3% of tin powder, 1-3% of titanium powder, 10-13% of ultrafine-particle-size calcined coke, 9-11% of carbon fiber powder and 3-5% of polysilazane resin. The product prepared by the invention has good self-lubricating property, relatively low resistivity and relatively good compressive strength, can maintain a relatively long service life in a salt mist region environment, and has a good economic prospect.

Description

Technical Field

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

[0002] The pantograph slide is the core conductive component for electric locomotives, high-speed railways and subway trains to obtain electrical energy from the overhead contact network. The pantograph slide needs to work under the combined working conditions of dynamic sliding friction and large current transmission, and must have conductivity, mechanical strength and wear resistance.

[0003] Currently, pantograph slides still face some problems, such as severe salt spray corrosion in coastal areas, which will cause damage to the life of the pantograph slides, resulting in frequent replacement of pantograph slides, and further economic losses.

[0004] For this reason, the present invention is specially proposed to solve this technical problem. Summary of the Invention

[0005] Aiming at the problem that existing pantograph slide plate materials have a short service life in a humid environment, the present invention provides a carbon-copper composite material for a pantograph slide plate and a preparation method thereof.

[0006] The technical solution of the present invention to solve the above technical problems is as follows: The present invention first provides a carbon-copper composite material for a pantograph slide. The carbon-copper composite material for a pantograph slide is composed of the following components in percentage by mass: 65-68% copper powder, 3-5% chromium powder, 1-3% tin powder, 1-3% titanium powder, 10-13% ultrafine particle size calcined coke, 9-11% carbon fiber powder, and 3-5% polysilazane resin.

[0007] Preferably, the fineness of the ultrafine 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.

[0008] The present invention further provides a method for preparing the carbon-copper composite material for a pantograph, comprising the following steps: S1. Weigh a carbon-copper composite material for a pantograph slide as described in claims 1 to 2; S2. Reducing the copper powder at a temperature of 400-450° C. under ammonia decomposition gas protection, keeping the temperature for 3 hours, and then air-cooling to room temperature. The reduced copper powder is ball-milled and sieved through a standard sieve of corresponding particle size; S3, adding ultrafine particle size calcined coke, carbon fiber powder, copper powder, chromium powder, tin powder, and titanium powder in descending order of particle size into a V-type mixer for 1-2 hours to obtain mixed powder 1; S4, pouring the mixed powder 1 and the polysilazane resin into a biaxial kneader and kneading them for 30-60 minutes to obtain a mixed material 2; S5. Place the above mixture in a hydraulic press, pre-press and exhaust with 50-80 MPa, then increase the pressure to the target pressure and slowly press into a green embryo, then quickly release the pressure and slowly demould; S6. Pressing the green compact by isostatic pressing at a pressure of 150-200 MPa; S7. Place the green body in a sintering furnace filled with nitrogen atmosphere at a sintering temperature of 1300° C. to obtain a carbon-copper composite material for a pantograph.

[0009] Preferably, in step S3, the mixer rotates at a speed of 20-30 rpm.

[0010] Preferably, in step S4, the kneading machine has a rotation speed of 50-60 rpm and a kneading temperature of 150-200°C.

[0011] Preferably, in step S5, the target pressure is 100-150 MPa, the holding time is 10-15 min, and the pressing speed is 0.5-1.0 mm / s.

[0012] Preferably, in step S6, the sintering temperature is increased to 600°C at a heating rate of 5°C / h, kept at that temperature for 1-2 hours, and then increased to 1300°C at a heating rate of 2°C / h, kept at that temperature for 10-15 hours.

[0013] The beneficial effects of the present invention are: The present invention uses small-particle raw materials, which are fed into a mixer in descending order of particle size. Compression, sintering, and secondary re-compression enhance the density of the mixture, reduce porosity, and improve mechanical strength. Ultrafine calcined coke, selected for its high-temperature sintering, transforms its disordered carbon structure into a graphite microcrystalline structure, reducing porosity and shrinking volume, forming a conductive network. The addition of chromium, tin, and titanium powders enhances the overall material's bonding strength, resulting in improved performance and a tighter bond. Polysilazane resin, added as a binder, is used to generate SiCN ceramic materials during high-temperature sintering, increasing material hardness and protecting the substrate from salt spray corrosion. DETAILED DESCRIPTION

[0014] The following is a clear and complete description of the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0015] Example 1 The carbon-copper composite material for pantograph provided in this embodiment is composed of the following components in percentage by mass: 65% copper powder, 5% chromium powder, 3% tin powder, 3% titanium powder, 10% ultrafine particle size calcined coke, 9% carbon fiber powder and 5% polysilazane resin.

[0016] The method for preparing the carbon-copper composite material for a pantograph provided in this embodiment comprises the following steps: S1. Weigh a carbon-copper composite material for a pantograph slide as described in claims 1 to 2; S2, reducing the copper powder at a temperature of 400°C under ammonia decomposition gas protection, keeping the temperature for 3 hours and then air-cooling to room temperature, and the reduced copper powder is ball-milled and sieved through a standard sieve of corresponding particle size; S3, weighing 500-mesh ultrafine calcined coke, 300-mesh copper powder, chromium powder, tin powder, titanium powder and 200-mesh carbon fiber powder according to the proportion, adding them into a V-type mixer in descending order of particle size, adjusting the mixer speed to 20 rpm, and mixing for 2 h to obtain mixed powder 1; S4, pouring the mixed powder 1 and the polysilazane resin into a biaxial kneader for kneading, setting the kneader speed to 50 rpm, the kneading time to 60 min, and the kneading temperature to 150° C. to obtain a mixed material 2; S5. Place the above mixture in a hydraulic press, pre-press and exhaust with 50 MPa, then increase the pressure to 150 MPa, and slowly press at 0.5 mm / s to form a green embryo, hold the pressure for 10 minutes, then quickly release the pressure and slowly demould; S6, re-pressing the green body by isostatic pressing at a pressure of 150 MPa; S7. Place the green body in a sintering furnace with a nitrogen atmosphere, heat it to 600°C at a heating rate of 5°C / h, keep it warm for 1 hour, then heat it to 1300°C at a heating rate of 2°C / h, keep it warm for 15 hours, and obtain a carbon-copper composite material for pantograph.

[0017] Example 2 The carbon-copper composite material for pantograph provided in this embodiment is composed of the following components in percentage by mass: 68% copper powder, 3% chromium powder, 1% tin powder, 1% titanium powder, 13% ultrafine particle size calcined coke, 11% carbon fiber powder and 3% polysilazane resin.

[0018] The method for preparing the carbon-copper composite material for a pantograph provided in this embodiment comprises the following steps: S1. Weigh a carbon-copper composite material for a pantograph slide as described in claims 1 to 2; S2, reducing the copper powder at a temperature of 450°C under ammonia decomposition gas protection, keeping the temperature for 3 hours and then air-cooling to room temperature, and the reduced copper powder is ball-milled and sieved through a standard sieve of corresponding particle size; S3, weighing 600-mesh ultrafine particle size calcined coke, 400-mesh copper powder, chromium powder, tin powder, titanium powder and 300-mesh carbon fiber powder according to the proportion, adding them into a V-type mixer in descending order of particle size, adjusting the mixer speed to 30 rpm and the mixing time to 1 h to obtain mixed powder 1; S4, pouring the mixed powder 1 and the polysilazane resin into a biaxial kneader for kneading, setting the kneader speed to 60 rpm, the kneading time to 30 min, and the kneading temperature to 200° C. to obtain a mixed material 2; S5. Place the above mixture in a hydraulic press, pre-press with 80 MPa to exhaust, then increase the pressure to 100 MPa, and slowly press at 1.0 mm / s to form a green embryo, hold the pressure for 15 minutes, then quickly release the pressure and slowly demould; S6, re-pressing the green body by isostatic pressing at a pressure of 200 MPa; S7. Place the above-mentioned green body in a sintering furnace with a nitrogen atmosphere, heat it to 600°C at a heating rate of 5°C / h, keep it warm for 2 hours, then heat it to 1300°C at a heating rate of 2°C / h, keep it warm for 10 hours, and obtain a carbon-copper composite material for pantograph slide.

[0019] Example 3 The carbon-copper composite material for pantograph provided in this embodiment is composed of the following components in percentage by mass: 66% copper powder, 4% chromium powder, 2% tin powder, 2% titanium powder, 12% ultrafine particle size calcined coke, 10% carbon fiber powder and 4% polysilazane resin.

[0020] The method for preparing the carbon-copper composite material for a pantograph provided in this embodiment comprises the following steps: S1. Weigh a carbon-copper composite material for a pantograph slide as described in claims 1 to 2; S2, reducing the copper powder at a temperature of 425°C under ammonia decomposition gas protection, keeping the temperature for 3 hours and air-cooling it to room temperature, and then ball-milling the reduced copper powder and sieving it through a standard sieve of corresponding particle size; S3, weighing 600-mesh ultrafine particle size calcined coke, 400-mesh copper powder, chromium powder, tin powder, titanium powder and 300-mesh carbon fiber powder according to the proportion, adding them into a V-type mixer in descending order of particle size, adjusting the mixer speed to 25 rpm and the mixing time to 1.5 h to obtain mixed powder 1; S4, pouring the mixed powder 1 and the polysilazane resin into a biaxial kneader for kneading, setting the kneader speed to 55 rpm, the kneading time to 45 min, and the kneading temperature to 180° C. to obtain a mixed material 2; S5. Place the above mixture in a hydraulic press, pre-press and exhaust with 65 MPa, then increase the pressure to 120 MPa, and slowly press at 0.8 mm / s to form a green embryo, hold the pressure for 12 minutes, then quickly release the pressure and slowly demould; S6, re-pressing the green body by isostatic pressing at a pressure of 170 MPa; S7. Place the above-mentioned green body in a sintering furnace with a nitrogen atmosphere, heat it to 600°C at a heating rate of 5°C / h, keep it warm for 1.5 hours, then heat it to 1300°C at a heating rate of 2°C / h, keep it warm for 13 hours, and obtain a carbon-copper composite material for pantograph slide.

[0021] Comparative Example 1 The difference from Example 3 is that the chromium powder, tin powder and titanium powder are replaced by copper powder with equal mass fractions, and the preparation method is basically the same as that of Example 3.

[0022] Comparative Example 2 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.

[0023] Comparative Example 3 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.

[0024] Experimental Example 1 The pantograph carbon-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests on a wear test bench, with the railway industry standard TB / T 1842.1-2002 used as a comparison. The experimental data results are shown in Table 1 below: Table 1 It can be seen from the above tests that all data of the embodiment are improved compared with the comparative example. 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 chromide to resist sliding wear; tin has a low melting point and produces a liquid phase during powder metallurgy sintering, which promotes particle rearrangement and pore filling, thereby increasing material density; titanium is a strong carbide-forming element, pinning grain boundaries to hinder grain growth, thereby increasing strength and toughness, and can improve the wettability of the metal and ceramic interface, thereby improving material properties.

[0025] Experimental Example 2 The pantograph carbon-copper composite materials of Examples 1-3 and Comparative Examples 1-3 were subjected to salt spray corrosion resistance test performance tests, and the neutral salt spray test (NSS) was performed on the carbon-copper composite materials for pantographs in accordance with the national standard GB / T 10125-2021. The test time was 720 h, and then the pantograph slide weight wear ratio g / 10,000 locomotive kilometers was tested on the wear test bench. The performance degradation rate was calculated according to the following formula. The experimental data results are shown in Table 2 below: Performance degradation rate = (weight wear ratio after salt spray resistance - weight wear ratio before salt spray resistance) / weight wear ratio before salt spray resistance * 100%.

[0026] Table 2 It can be seen from the above tests that in the comparative example, the polysilazane resin was replaced, and the SiCN ceramic material was not produced, resulting in a significant decrease in the mechanical properties and salt spray resistance of the pantograph slide material. At the same time, the addition of polysilazane resin can improve the conductive properties of the material; in comparative example 2, carbon fiber was replaced with ordinary carbon powder, which also resulted in lower strength.

[0027] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A carbon-copper composite material for a pantograph slide, characterized in that: The invention is composed of the following components in percentage by mass: 65-68% copper powder, 3-5% chromium powder, 1-3% tin powder, 1-3% titanium powder, 10-13% ultrafine particle size calcined coke, 9-11% carbon fiber powder and 3-5% polysilazane resin.

2. The carbon-copper composite material for a pantograph slide according to claim 1, characterized in that: The fineness of the ultrafine 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.

3. A method for preparing a carbon-copper composite material for a pantograph slide, characterized in that: The following steps are involved: S1. Weigh a carbon-copper composite material for a pantograph slide as described in claims 1 to 2; S2. Reducing the copper powder at a temperature of 400-450° C. under ammonia decomposition gas protection, keeping the temperature for 3 hours, and then air-cooling to room temperature. The reduced copper powder is ball-milled and sieved through a standard sieve of corresponding particle size; S3, adding ultrafine particle size calcined coke, carbon fiber powder, copper powder, chromium powder, tin powder, and titanium powder in descending order of particle size into a V-type mixer for 1-2 hours to obtain mixed powder 1; S4, pouring the mixed powder 1 and the polysilazane resin into a biaxial kneader and kneading them for 30-60 minutes to obtain a mixed material 2; S5. Place the above mixture in a hydraulic press, pre-press and exhaust with 50-80 MPa, then increase the pressure to the target pressure and slowly press into a green embryo, then quickly release the pressure and slowly demould; S6. Pressing the green compact by isostatic pressing at a pressure of 150-200 MPa; S7. Place the green body in a sintering furnace filled with nitrogen atmosphere at a sintering temperature of 1300° C. to obtain a carbon-copper composite material for a pantograph.

4. The method for preparing a carbon-copper composite material for a pantograph slide according to claim 3, characterized in that: In step S3, the mixer rotates at a speed of 20-30 rpm.

5. The method for preparing a carbon-copper composite material for a pantograph slide according to claim 3, characterized in that: In step S4, the kneading machine has a rotation speed of 50-60 rpm and a kneading temperature of 150-200°C.

6. The method for preparing a carbon-copper composite material for a pantograph slide according to claim 3, characterized in that: In step S5, the target pressure is 100-150 MPa, the holding time is 10-15 min, and the pressing speed is 0.5-1.0 mm / s.

7. The method for preparing a carbon-copper composite material for a pantograph slide according to claim 3, characterized in that: In step S6, the sintering temperature is increased to 600° C. at a heating rate of 5° C. / h, kept at that temperature for 1-2 hours, and then increased to 1300° C. at a heating rate of 2° C. / h, kept at that temperature for 10-15 hours.

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