A silver-containing copper-based carbon brush for a transportation vehicle and a preparation method thereof

Abstract

The present invention provides a preparation method of a silver-containing copper-based carbon brush for a transportation vehicle, comprising the following steps: Step 1, weighing raw materials according to parts by weight: 80-82 parts of copper, 5-8 parts of a balance agent doped with calcined alumina, 5-7 parts of a property stability regulator, 4-6 parts of tin, 3-5 parts of molybdenum disulfide powder with a mesh size of 500, 1-3 parts of silver, and 4-6 parts of carbon powder with a mesh size of 1000. The present invention uses copper, tin, molybdenum disulfide powder with a mesh size of 500, silver, and carbon powder with a mesh size of 1000 as matrix materials, and through the addition of a balance agent doped with calcined alumina and a property stability regulator, the two are coordinated and synergistic, so that the conductivity, wear resistance, and mechanical strength of the obtained silver-containing copper-based carbon brush are balanced and improved, and the product has remarkable effects of salt corrosion resistance and thermal cycle stability resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of silver-containing copper-based carbon brushes, and specifically relates to a silver-containing copper-based carbon brush for transportation vehicles and a preparation method thereof. Background Art

[0002] A carbon brush is a friction-conductive conductor and a mechanical and electrical component with the function of transmitting current. As a key current-conducting component of the grounding device of the bogie of rail transit vehicles (high-speed trains, bullet trains, subways), through close contact and frictional commutation with the slip ring or friction disc (pressed on the bogie axle), the eddy current inside the axle is conducted to the grounding cable connected to the grounding device, realizing a dynamic current closed loop.

[0003] In the grounding device, the carbon brush is installed in the brush groove of the carbon brush holder and can slide up and down. It is in close contact with the slip ring or friction disc through the pressure of the compression spring. The brush braid of the carbon brush is connected to the carbon brush holder. The carbon brush holder is connected to the external grounding cable. During the high-speed operation (300 km / h to 400 km / h) of the vehicle, the slip ring or friction disc also rotates at high speed (2400 revolutions per minute, bidirectional) following the axle. As a current transmission component, the carbon brush must maintain sliding contact with the slip ring or friction disc and generate losses due to high-speed friction. Therefore, the carbon brush is a consumable part and must be replaced after reaching a certain service time or a certain degree of wear. However, the existing carbon brushes have poor electrical conductivity, and it is difficult to balance and coordinate the improvement of the electrical conductivity, wear resistance, and mechanical strength of the products. In addition, the salt corrosion resistance and the stability of resistance to thermal cycling of the products are poor, which further limits the use performance of the products. Summary of the Invention

[0004] Aiming at the defects of the prior art, the purpose of the present invention is to provide a silver-containing copper-based carbon brush for transportation vehicles and a preparation method thereof to solve the problems raised in the above background art.

[0005] The present invention adopts the following technical solutions to solve the technical problems:

[0006] The present invention provides a preparation method of a silver-containing copper-based carbon brush for transportation vehicles, including the following steps:

[0007] Step 1, weighing raw materials according to parts by weight: 80 - 82 parts of copper, 5 - 8 parts of a balance agent doped with calcined alumina, 5 - 7 parts of a stability regulator, 4 - 6 parts of tin, 3 - 5 parts of molybdenum disulfide powder with a mesh size of 500, 1 - 3 parts of silver, and 4 - 6 parts of carbon powder with a mesh size of 1000;

[0008] Step 2, uniformly mixing the raw materials in Step 1, then performing pressure molding in a mold, followed by sintering and improvement treatment. After sintering is completed, demold.

[0009] Step 3: Heat the polyethylene wax until it melts, immerse the brush body processed in Step 2 into the melted polyethylene wax under an immersion pressure of 10 MPa for 60 minutes; perform ultrasonic vibration cleaning on the immersed brush body 3 times, then wipe off the excess fat liquid on the surface with absorbent paper and let it cool naturally to obtain the silver-containing copper-based carbon brush of the present invention.

[0010] Preferably, the purity of both the copper and tin is not less than 99.5%; the purity of silver is not less than 99.9%;

[0011] The holding pressure for the pressure holding and forming is 80 MPa, and the holding time is 10 min;

[0012] The sintering temperature for the sintering improvement treatment is 850 - 1000 °C, sinter for 2 h, and then cool to room temperature at a rate of 2 - 5 °C / min.

[0013] Preferably, the preparation method of the balance agent doped with calcined alumina is as follows:

[0014] S01: Irradiate the aluminum borate whiskers in a proton irradiation chamber for 5 - 10 min with an irradiation power of 350 W, and then the irradiation ends;

[0015] S02: Stir and mix silicon carbide and a lanthanum chloride solution with a mass fraction of 2 - 5% evenly according to a weight ratio of 2:5 to obtain a silicon carbide agent;

[0016] Add 1 - 2 parts of stearic acid and 1 - 3 parts of silane coupling agent KH560 to 5 - 8 parts of the sodium lignosulfonate solution, and then add 2 - 4 parts of the silicon carbide agent and mix evenly to obtain a leveling modifier;

[0017] S03: Perform ultrasonic modification treatment on the irradiated aluminum borate whiskers and the leveling modifier according to a weight ratio of 3:7. After the ultrasonic treatment ends, obtain an aluminum borate whisker leveling liquid;

[0018] S04: Mix and ball-mill the calcined alumina and the aluminum borate whisker leveling liquid according to a weight ratio of 5:(2 - 3). The ball-milling speed is 1500 r / min, and ball-mill for 1 h. After the ball-milling ends, wash with water and dry to obtain the balance agent doped with calcined alumina.

[0019] Preferably, the mass fraction of the sodium lignosulfonate solution is 4 - 6%.

[0020] Preferably, the ultrasonic power for the ultrasonic modification treatment is 350 - 400 W, and the ultrasonic time is 20 - 30 min.

[0021] Preferably, the preparation method of the calcined alumina is as follows:

[0022] First, heat the alumina at a rate of 1-3 °C / min to 210-220 °C, hold for 5-10 min, then heat at a rate of 2-5 °C / min to 350 °C, continue to hold for 2-5 min, and finally air-cool to room temperature;

[0023] Mix and ball-mill 5-8 parts of alumina air-cooled to room temperature, 2-4 parts of nano-bentonite, 1-2 parts of hydrochloric acid dopamine solution, and 5-8 parts of yttrium nitrate solution. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water and dry to obtain calcined alumina.

[0024] Preferably, the mass fraction of the hydrochloric acid dopamine solution is 2-4%; the mass fraction of the yttrium nitrate solution is 3-6%.

[0025] Preferably, the preparation method of the stability regulator is as follows:

[0026] S11: First, stir and mix the zirconium silicate fiber thoroughly in a sufficient amount of 5% potassium permanganate solution by mass fraction, then wash with water and dry. Immerse the dried zirconium silicate fiber in a sufficient amount of 5% sodium silicate solution by mass fraction and stir. After stirring, filter by suction and dry to obtain modified zirconium silicate fiber;

[0027] S12: Mix and ball-mill 5-8 parts of modified zirconium silicate fiber, 1-3 parts of dodecylbenzenesulfonic acid sodium solution with a mass fraction of 2-4%, 2-5 parts of carboxymethyl cellulose, 6-8 parts of chitosan solution with a mass fraction of 4%, and 2-4 parts of boron nitride. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water, filter by suction and dry to obtain the stability regulator.

[0028] Preferably, the stirring speed of the stirring treatment in S11 is 450-500 r / min, and stir for 20-30 min.

[0029] The present invention also provides a silver-containing copper-based carbon brush prepared by the preparation method of a silver-containing copper-based carbon brush for a transportation vehicle.

[0030] For the silver-containing copper-based carbon brush of the present invention, the chemical composition and advanced functions of its main material are briefly described as follows:

[0031] Copper, with good electrical conductivity, plasticity, and toughness. As the main matrix material, copper is added to the carbon brush body in the form of tin bronze alloy powder and cooperates with other materials to achieve the characteristics of high physical strength, high toughness, high stability, and high current conduction ability, ensuring that various index parameters such as the bending strength, shear strength, and current strength of the carbon brush meet the standards.

[0032] Tin is added in the form of tin bronze alloy powder with copper and tin as the main alloying elements, which is mainly used to make elastic components and wear-resistant parts. This alloy has high mechanical properties, antifriction properties and corrosion resistance, is easy to machine, has a small shrinkage coefficient and is non-magnetic. It improves the overall physical performance indicators of the carbon brush, and has the characteristics of small deformation, easy machining and shaping, and non-magnetism. During the operation of the carbon brush, part of the tin component is oxidized, but tin oxide is a strong conductive material, which helps to improve the conductivity and service life of the carbon brush.

[0033] Carbon. After the mixed metal powder is formed, most of the carbon powder is converted into graphite, which plays a lubricating role, and a small part remains in the form of free carbon powder. This form has poor adhesion to metals and is easy to peel off and fall off to form a network gap. Therefore, there is a key process after melting and casting the brush body, which is soaking, allowing a fine molecular fatty solution to infiltrate these gaps and adhere to the brush body, playing the roles of conducting electricity, heat transfer, lubrication, reducing the friction coefficient, and enhancing the contact and fitting ability of the carbon brush during the application of the carbon brush.

[0034] Molybdenum disulfide is a solid lubricant, and its main function is to reduce the friction coefficient and improve the wear resistance. However, due to the certain corrosiveness of molybdenum disulfide to copper, adding too high a proportion will affect the structural stability of the main body of the carbon brush body. Therefore, an appropriate proportion of molybdenum disulfide is generally added to the brush body. Soaking the brush body with a fatty solution after melting and casting and processing and shaping also has the effect of stabilizing the state of molybdenum disulfide.

[0035] Silver is added in the form of a copper-tin-silver alloy and a silver-containing tin bronze powder.

[0036] The silver-containing copper-based carbon brush of the present invention has the following advanced technical features:

[0037] 1. The metal silver component contained in the silver-containing copper-based carbon brush body of the present invention is added in the form of ultrafine powder of a silver-containing tin bronze alloy body with a silver content. Examples show that it greatly improves the mechanical strength, conductivity and service life of the carbon brush body;

[0038] Silver has stable chemical properties, good electrical and thermal conductivity. Silver-copper alloy is a eutectic alloy with a mutual solid solubility limit. The characteristics of copper-silver alloy are fine crystallization, no brittleness, good wear resistance, and good electrical conductivity (reducing contact resistance), fluidity (easy to machine) and wettability (strong adhesion). The carbon brush added with silver powder improves the conductivity of the carbon brush (reducing resistivity and voltage drop), reduces electric erosion (the contact resistance between the carbon brush and the slip ring or friction disc decreases, the contact property enhances, and the contact arc discharge phenomenon during strong current conduction is greatly reduced, and the sintering loss caused by arc discharge is also greatly reduced). Due to its good adhesion performance, the effect of the fatty infiltration solution can be maximally exerted;

[0039] 2. After the carbon brush body of the present invention is sintered and formed, soaking (impregnating) with a fatty solution is also a very crucial process step. It forms a semiconductor conductive bridge in the small space near the friction surface, actively intervenes in the physical conditions for forming an arc between the carbon brush and the slip ring, and strongly resists the generation of the arc. This not only greatly increases the service life of the carbon brush but also significantly promotes the driving safety. The carbon brush is a consumable. During the working process, the brush body is in close contact with and rubs against the collector ring or the friction disc. There are mainly two ways of wear of the carbon brush:

[0040] Through the protection of the conductive oil film of the infiltrating solution in this technical solution, the generation rate of the new oxide film is reduced, and the thickness of the oxide film on the carbon brush contact surface is always maintained at about 0.01 mm. After testing, when the vehicle runs 500,000 kilometers, the decay of various technical indicators of the carbon brush does not exceed 5%; when the vehicle runs 800,000 kilometers, the decay of the comprehensive technical indicators of the carbon brush does not exceed 10%.

[0041] To sum up, the technical solution of the present invention can increase the average service life of the carbon brush by 1 to 1.5 times, enable the service life of the collector ring and the friction disc to reach or even exceed the design expectation, and greatly reduce the operation and maintenance costs of the rail vehicle.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] According to the newly formulated material formula of the carbon brush body of the present invention, the content of silver element is increased to 2 parts. According to the good electrical conductivity and thermal conductivity of the silver element, the specific resistivity is reduced, the voltage drop is reduced, and the working temperature is reduced; a fatty infiltrating solution is used to enhance the electrical conductivity, reduce the friction coefficient, reduce the contact spark, and stabilize the operating parameters, so that the technical indicators of the carbon brush remain relatively stable throughout the service life, and to a certain extent, the wear on the collector ring or the friction disc is also reduced;

[0044] Copper, tin, molybdenum disulfide powder with a mesh size of 500, silver, and carbon powder with a mesh size of 1000 are used as matrix materials. By adding a balance agent doped with calcined alumina and a property stability regulator, the two are coordinated and synergistic. The obtained silver-containing copper-based carbon brush has improved balance and coordination in electrical conductivity, wear resistance, and mechanical strength, and the product has significant effects in salt corrosion resistance and thermal cycle stability. The balance agent doped with calcined alumina is proton-irradiated through aluminum borate whiskers to optimize its activity efficiency. Then, stearic acid and silane coupling agent KH560 are added to the sodium lignosulfonate solution and combined with silicon carbide agent. Through the coordination of raw materials, a leveling modifier is obtained. The silicon carbide agent is prepared by combining silicon carbide with lanthanum chloride solution. In the system, the raw materials can be better coordinated, so that the aluminum borate whisker leveling solution can better coordinate and synergize with calcined alumina. The calcined alumina is first heated from room temperature to 210-220°C at a rate of 1-3°C / min and held for 5-10 minutes, then heated to 350°C at a rate of 2-5°C / min and held for 2-5 minutes. Through step-by-step thermal improvement, the activity efficiency of alumina is optimized. Then, through the co-milling treatment of nanobentonite, dopamine hydrochloride solution, and yttrium nitrate solution, through the coordination of raw materials, they are jointly coordinated. By using the co-allocation and synergistic effect of raw materials, nanobentonite is combined with alumina to enhance the performance coordination and performance stability of the product in the system. The property stability regulator is improved by activating zirconium silicate fiber with potassium permanganate, and then stirred with sodium silicate solution. At the same time, through the co-milling treatment of sodium dodecylbenzene sulfonate solution, carboxymethyl cellulose, chitosan solution with a mass fraction of 4%, and boron nitride, through the coordination and synergistic effect of raw materials, the reinforcing effect of the property stability regulator and the balance agent doped with calcined alumina is enhanced, and the performance of the product is further improved. Detailed implementation mode

[0045] The following is a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with specific embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present invention.

[0046] A preparation method of a silver-containing copper-based carbon brush for a transportation vehicle in this embodiment includes the following steps:

[0047] Step 1: Weigh the raw materials according to parts by weight: 80-82 parts of copper, 5-8 parts of a balance agent doped with calcined alumina, 5-7 parts of a property stability regulator, 4-6 parts of tin, 3-5 parts of molybdenum disulfide powder with a mesh size of 500, 1-3 parts of silver, and 4-6 parts of carbon powder with a mesh size of 1000;

[0048] Step 2, the raw materials in step 1 are mixed thoroughly, and then pressure-formed in a mold, and then sintered and improved. After sintering, demoulding is completed;

[0049] Step three, heating the polyethylene wax until it melts, immersing the brush body processed in step two into the melted polyethylene wax, with an immersion pressure of 10 MPa and immersion for 60 minutes; subjecting the immersed brush body to ultrasonic vibration cleaning for 3 times, and then wiping off excess grease on the surface with oil-absorbing paper, and cooling naturally to obtain the silver-containing copper-based carbon brush of the present invention.

[0050] The purity of copper and tin in this embodiment is not less than 99.5%; the purity of silver is not less than 99.9%;

[0051] The holding pressure of the pressure-holding molding is 80 MPa, and the holding time is 10 min;

[0052] The sintering temperature of the sintering improvement treatment is 850-1000° C., sintering for 2 hours, and then cooling to room temperature at a rate of 2-5° C. / min.

[0053] The preparation method of the balance agent doped with calcined alumina in this embodiment is:

[0054] S01: irradiate the aluminum borate whiskers in a proton irradiation box for 5-10 minutes at a power of 350W, and then the irradiation ends;

[0055] S02: Stir and mix silicon carbide and 2-5% by mass lanthanum chloride solution in a weight ratio of 2:5 to obtain a silicon carbide agent;

[0056] 1-2 parts of stearic acid and 1-3 parts of silane coupling agent KH560 are added to 5-8 parts of sodium lignin sulfonate solution, and then 2-4 parts of silicon carbide agent are added and mixed to obtain a leveling modifier;

[0057] S03: subjecting the irradiated aluminum borate whiskers and the leveling modifier to ultrasonic modification in a weight ratio of 3:7, and completing the ultrasonic modification to obtain an aluminum borate whisker leveling solution;

[0058] S04: Mix the calcined alumina and aluminum borate whisker leveling liquid in a weight ratio of 5:(2-3) and perform ball milling at a ball milling speed of 1500r / min for 1h. After the ball milling is completed, wash with water and dry to obtain a balancing agent doped with calcined alumina.

[0059] The mass fraction of the sodium lignin sulfonate solution in this embodiment is 4-6%.

[0060] The ultrasonic power of the ultrasonic modification treatment in this embodiment is 350-400W, and the ultrasonic time is 20-30min.

[0061] The preparation method of calcined alumina in this embodiment is:

[0062] First, heat the alumina to 210 - 220 °C at a rate of 1 - 3 °C / min, hold for 5 - 10 min, then heat to 350 °C at a rate of 2 - 5 °C / min, continue to hold for 2 - 5 min, and finally air-cool to room temperature;

[0063] Mix and ball-mill 5 - 8 parts of the alumina air-cooled to room temperature, 2 - 4 parts of nano-bentonite, 1 - 2 parts of dopamine hydrochloride solution, and 5 - 8 parts of yttrium nitrate solution. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water and dry to obtain calcined alumina.

[0064] In this example, the mass fraction of the dopamine hydrochloride solution is 2 - 4%; the mass fraction of the yttrium nitrate solution is 3 - 6%.

[0065] The preparation method of the property stability regulator in this example is as follows:

[0066] S11: First, stir and mix the zirconium silicate fiber thoroughly in a sufficient amount of 5% potassium permanganate solution by mass fraction, then wash with water and dry. Immerse the dried zirconium silicate fiber in a sufficient amount of 5% sodium silicate solution by mass fraction and stir. After stirring, filter and dry to obtain modified zirconium silicate fiber;

[0067] S12: Mix and ball-mill 5 - 8 parts of modified zirconium silicate fiber, 1 - 3 parts of 2 - 4% sodium dodecylbenzenesulfonate solution by mass fraction, 2 - 5 parts of carboxymethyl cellulose, 6 - 8 parts of 4% chitosan solution by mass fraction, and 2 - 4 parts of boron nitride. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water, filter, and dry to obtain the property stability regulator.

[0068] In S11 of this example, the stirring speed of the stirring treatment is 450 - 500 r / min, and stir for 20 - 30 min.

[0069] A silver-copper-based carbon brush for a transportation vehicle prepared by the preparation method of a silver-copper-based carbon brush in this example.

[0070] Example 1.

[0071] The preparation method of a silver-copper-based carbon brush for a transportation vehicle in this example includes the following steps:

[0072] Step 1, weigh the raw materials by weight: 80 parts of copper, 5 parts of a balance agent doped with calcined alumina, 5 parts of a property stability regulator, 4 parts of tin, 3 parts of molybdenum disulfide powder with a mesh size of 500, 1 part of silver, and 4 parts of carbon powder with a mesh size of 1000;

[0073] Step 2, mix the raw materials in Step 1 thoroughly, then press and mold in a mold, and then perform sintering improvement treatment. After sintering, demold;

[0074] Step 3: Heat the polyethylene wax until it melts. Immerse the brush body processed in Step 2 into the melted polyethylene wax under an immersion pressure of 10 MPa for 60 minutes. Conduct ultrasonic vibration cleaning on the immersed brush body three times, then wipe off the excess fat liquid on the surface with absorbent paper and let it cool naturally to obtain the silver-containing copper-based carbon brush of the present invention.

[0075] In this embodiment, the purity of both copper and tin is not less than 99.5%; the purity of silver is not less than 99.9%;

[0076] The holding pressure for the pressure holding and forming is 80 MPa, and the holding time is 10 min;

[0077] The sintering temperature for the sintering improvement treatment is 850 °C, sinter for 2 h, and then cool to room temperature at a rate of 2 °C / min.

[0078] The preparation method of the balance agent doped with calcined alumina in this embodiment is as follows:

[0079] S01: Irradiate the aluminum borate whiskers in a proton irradiation chamber for 5 min with an irradiation power of 350 W, and then the irradiation ends;

[0080] S02: Stir and mix silicon carbide and a lanthanum chloride solution with a mass fraction of 2% in a weight ratio of 2:5 to obtain a silicon carbide agent;

[0081] Add 1 part of stearic acid and 1 part of silane coupling agent KH560 to 5 parts of the sodium lignosulfonate solution, and then add 2 parts of the silicon carbide agent and mix well to obtain a leveling modifier;

[0082] S03: Perform ultrasonic modification treatment on the irradiated aluminum borate whiskers and the leveling modifier in a weight ratio of 3:7. After the ultrasonic treatment ends, obtain an aluminum borate whisker leveling liquid;

[0083] S04: Mix and ball-mill the calcined alumina and the aluminum borate whisker leveling liquid in a weight ratio of 5:2. The ball-milling speed is 1500 r / min, and ball-mill for 1 h. After the ball-milling ends, wash with water and dry to obtain the balance agent doped with calcined alumina.

[0084] The mass fraction of the sodium lignosulfonate solution in this embodiment is 4%.

[0085] The ultrasonic power for the ultrasonic modification treatment in this embodiment is 350 W, and the ultrasonic time is 20 min.

[0086] The preparation method of the calcined alumina in this embodiment is as follows:

[0087] First, heat the alumina to 210 °C at a rate of 1 °C / min, hold for 5 min, then heat to 350 °C at a rate of 2 °C / min, continue to hold for 2 min, and finally air-cool to room temperature;

[0088] Mix 5 parts of alumina air-cooled to room temperature, 2 parts of nano-bentonite, 1 part of dopamine hydrochloride solution, and 5 parts of yttrium nitrate solution, and perform ball milling. The ball milling speed is 1000 r / min, and the ball milling time is 2 h. After the ball milling is completed, wash with water and dry to obtain calcined alumina.

[0089] In this example, the mass fraction of the dopamine hydrochloride solution is 2%; the mass fraction of the yttrium nitrate solution is 3%.

[0090] The preparation method of the property stability regulator in this example is as follows:

[0091] S11: First, stir and mix zirconium silicate fibers sufficiently in a sufficient amount of potassium permanganate solution with a mass fraction of 5%, then wash with water and dry. Immerse the dried zirconium silicate fibers in a sufficient amount of sodium silicate solution with a mass fraction of 5% and stir. After the stirring is completed, filter and dry to obtain modified zirconium silicate fibers;

[0092] S12: Mix 5 parts of modified zirconium silicate fibers, 1 part of sodium dodecylbenzenesulfonate solution with a mass fraction of 2%, 2 parts of carboxymethyl cellulose, 6 parts of chitosan solution with a mass fraction of 4%, and 2 parts of boron nitride, and perform ball milling. The ball milling speed is 1000 r / min, and the ball milling time is 2 h. After the ball milling is completed, wash with water, filter, and dry to obtain the property stability regulator.

[0093] In S11 of this example, the stirring speed of the stirring treatment is 450 r / min, and the stirring time is 20 min.

[0094] The silver-containing copper-based carbon brush for a transportation vehicle prepared by the preparation method of a silver-containing copper-based carbon brush in this example.

[0095] Example 2.

[0096] The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle in this example includes the following steps:

[0097] Step 1, weigh the raw materials according to the parts by weight: 82 parts of copper, 8 parts of a balance agent doped with calcined alumina, 7 parts of a property stability regulator, 6 parts of tin, 5 parts of molybdenum disulfide powder with a mesh size of 500, 3 parts of silver, and 6 parts of carbon powder with a mesh size of 1000;

[0098] Step 2, mix the raw materials in Step 1 sufficiently, then perform pressure molding in a mold, and then perform sintering improvement treatment. After the sintering is completed, demold;

[0099] Step 3, heat the polyethylene wax until it melts. Immerse the brush body processed in Step 2 in the melted polyethylene wax. The immersion pressure is 10 MPa and the immersion time is 60 minutes; perform ultrasonic vibration cleaning on the immersed brush body 3 times, then wipe off the excess fat liquid on the surface with absorbent paper, and cool naturally to obtain the silver-containing copper-based carbon brush of the present invention.

[0100] The purity of copper and tin in this embodiment is not less than 99.5%; the purity of silver is not less than 99.9%;

[0101] The holding pressure for the pressure holding and forming is 80 MPa, and the holding time is 10 min;

[0102] The sintering temperature for the sintering improvement treatment is 1000 °C, sintering for 2 h, and then cooling to room temperature at a rate of 5 °C / min.

[0103] The preparation method of the balance agent of doped calcined alumina in this embodiment is as follows:

[0104] S01: Irradiate aluminum borate whiskers in a proton irradiation chamber for 10 min, with an irradiation power of 350 W, and the irradiation ends;

[0105] S02: Stir and mix silicon carbide and a 5% lanthanum chloride solution by weight ratio of 2:5 to obtain a silicon carbide agent;

[0106] Add 2 parts of stearic acid and 3 parts of silane coupling agent KH560 to 8 parts of sodium lignosulfonate solution, and then add 4 parts of the silicon carbide agent and mix well to obtain a leveling modifier;

[0107] S03: Perform ultrasonic modification treatment on the irradiated aluminum borate whiskers and the leveling modifier according to a weight ratio of 3:7. After the ultrasonic treatment ends, obtain an aluminum borate whisker leveling solution;

[0108] S04: Mix and ball-mill calcined alumina and the aluminum borate whisker leveling solution according to a weight ratio of 5:3. The ball-milling speed is 1500 r / min, ball-mill for 1 h. After the ball-milling ends, wash with water and dry to obtain the balance agent of doped calcined alumina.

[0109] The mass fraction of the sodium lignosulfonate solution in this embodiment is 6%.

[0110] The ultrasonic power of the ultrasonic modification treatment in this embodiment is 400 W, and the ultrasonic time is 30 min.

[0111] The preparation method of the calcined alumina in this embodiment is as follows:

[0112] First, heat the alumina to 220 °C at a rate of 3 °C / min, hold for 10 min, then heat to 350 °C at a rate of 5 °C / min, continue to hold for 5 min, and finally air-cool to room temperature;

[0113] Mix 8 parts of alumina air-cooled to room temperature, 4 parts of nano-bentonite, 2 parts of hydrochloric acid dopamine solution and 8 parts of yttrium nitrate solution and perform ball-milling treatment. The ball-milling speed is 1000 r / min, ball-mill for 2 h. After the ball-milling ends, wash with water and dry to obtain the calcined alumina.

[0114] The mass fraction of the dopamine hydrochloride solution in this embodiment is 4%; the mass fraction of the yttrium nitrate solution is 6%.

[0115] The preparation method of the stability regulator in this embodiment is as follows:

[0116] S11: First, stir and mix zirconium silicate fibers thoroughly in a sufficient amount of potassium permanganate solution with a mass fraction of 5%, then wash with water and dry. Immerse the dried zirconium silicate fibers in a sufficient amount of sodium silicate solution with a mass fraction of 5% and stir. After stirring, filter and dry to obtain modified zirconium silicate fibers;

[0117] S12: Blend and ball-mill 8 parts of modified zirconium silicate fibers, 3 parts of sodium dodecylbenzenesulfonate solution with a mass fraction of 4%, 5 parts of carboxymethyl cellulose, 8 parts of chitosan solution with a mass fraction of 4%, and 4 parts of boron nitride. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water, filter, and dry to obtain the stability regulator.

[0118] In S11 of this embodiment, the stirring speed of the stirring treatment is 500 r / min, and stir for 30 min.

[0119] The silver-containing copper-based carbon brush prepared by the preparation method of the silver-containing copper-based carbon brush for a transportation vehicle in this embodiment.

[0120] Example 3.

[0121] The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle in this embodiment includes the following steps:

[0122] Step 1, weigh the raw materials according to parts by weight: 81 parts of copper, 6.5 parts of a balance agent doped with calcined alumina, 6 parts of a stability regulator, 5 parts of tin, 4 parts of molybdenum disulfide powder with a mesh size of 500, 2 parts of silver, and 5 parts of carbon powder with a mesh size of 1000;

[0123] Step 2, mix the raw materials in Step 1 thoroughly, then carry out pressure molding in a mold, and then perform sintering improvement treatment. After sintering, demold;

[0124] Step 3, heat the polyethylene wax until it melts. Immerse the brush body processed in Step 2 into the melted polyethylene wax under an immersion pressure of 10 MPa for 60 minutes; perform 3 ultrasonic vibration cleanings on the immersed brush body, then wipe off the excess grease on the surface with absorbent paper, and cool naturally to obtain the silver-containing copper-based carbon brush of the present invention.

[0125] The purity of copper and tin in this embodiment is not less than 99.5%; the purity of silver is not less than 99.9%;

[0126] The pressure of the pressure molding is 80 MPa, and the pressure holding time is 10 min;

[0127] The sintering temperature of the improved sintering treatment is 885 °C, sintering for 2 h, and then cooling to room temperature at a rate of 3.5 °C / min.

[0128] The preparation method of the doping calcined alumina leveling agent in this embodiment is as follows:

[0129] S01: First irradiate aluminum borate whiskers in a proton irradiation box for 7.5 min, the irradiation power is 350 W, and the irradiation ends;

[0130] S02: Stir and mix silicon carbide and a lanthanum chloride solution with a mass fraction of 3.5% according to a weight ratio of 2:5 to obtain a silicon carbide agent;

[0131] Add 1.5 parts of stearic acid and 2 parts of silane coupling agent KH560 to 6.5 parts of sodium lignosulfonate solution, and then add 3 parts of the silicon carbide agent and mix well to obtain a leveling modifier;

[0132] S03: Perform ultrasonic modification treatment on the irradiated aluminum borate whiskers and the leveling modifier according to a weight ratio of 3:7. After the ultrasonic treatment ends, obtain an aluminum borate whisker leveling solution;

[0133] S04: Mix and ball-mill calcined alumina and the aluminum borate whisker leveling solution according to a weight ratio of 5:2.5. The ball-milling speed is 1500 r / min, ball-mill for 1 h. After the ball-milling ends, wash with water and dry to obtain a doping calcined alumina leveling agent.

[0134] The mass fraction of the sodium lignosulfonate solution in this embodiment is 5%.

[0135] The ultrasonic power of the ultrasonic modification treatment in this embodiment is 375 W, and the ultrasonic time is 25 min.

[0136] The preparation method of the calcined alumina in this embodiment is as follows:

[0137] First heat the alumina to 215 °C at a rate of 2 °C / min, hold for 7.5 min, then heat to 350 °C at a rate of 3.5 °C / min, continue to hold for 3.5 min, and finally air-cool to room temperature;

[0138] Mix 6.5 parts of alumina air-cooled to room temperature, 3 parts of nano-bentonite, 1.5 parts of dopamine hydrochloride solution and 6.5 parts of yttrium nitrate solution and perform ball-milling treatment. The ball-milling speed is 1000 r / min, ball-mill for 2 h. After the ball-milling ends, wash with water and dry to obtain calcined alumina.

[0139] The mass fraction of the dopamine hydrochloride solution in this embodiment is 3%; the mass fraction of the yttrium nitrate solution is 4.5%.

[0140] The preparation method of the stability regulator in this embodiment is as follows:

[0141] S11: First, mix zirconium silicate fibers thoroughly in a sufficient amount of 5% potassium permanganate solution by stirring, then wash with water and dry. Immerse the dried zirconium silicate fibers in a sufficient amount of 5% sodium silicate solution and stir. After stirring, perform suction filtration and drying to obtain modified zirconium silicate fibers;

[0142] S12: Blend and ball-mill 6.5 parts of modified zirconium silicate fibers, 2 parts of 3% sodium dodecylbenzenesulfonate solution, 3.5 parts of carboxymethyl cellulose, 7 parts of 4% chitosan solution, and 3 parts of boron nitride. The ball-milling speed is 1000 r / min, and ball-mill for 2 h. After ball-milling, wash with water, perform suction filtration and drying to obtain a stability regulator.

[0143] In S11 of this example, the stirring speed for the stirring treatment is 470 r / min, and stir for 25 min.

[0144] A silver-copper-based carbon brush for a transportation vehicle prepared by the preparation method of a silver-copper-based carbon brush in this example.

[0145] Comparative Example 1.

[0146] The difference from Example 3 is that a balance agent doped with calcined alumina is not added.

[0147] Comparative Example 2.

[0148] The difference from Example 3 is that in the preparation of the balance agent doped with calcined alumina, a borate whisker leveling solution treatment is not used.

[0149] Comparative Example 3.

[0150] The difference from Example 3 is that in the preparation of the borate whisker leveling solution, a leveling modifier treatment is not used.

[0151] Comparative Example 4.

[0152] The difference from Example 3 is that in the preparation of the leveling modifier, a silicon carbide agent is not added.

[0153] Comparative Example 5.

[0154] The difference from Example 3 is that the silicon carbide agent is directly replaced with silicon carbide.

[0155] Comparative Example 6.

[0156] The difference from Example 3 is that in the preparation of the leveling modifier, stearic acid and silane coupling agent KH560 are not added.

[0157] Comparative Example 7.

[0158] The difference from Example 3 is that in the preparation of the borate whisker leveling solution, irradiated borate whiskers are not used.

[0159] Comparative Example 8.

[0160] Different from Example 3, in the preparation of the equilibrium agent doped with calcined alumina, calcined alumina treatment was not used.

[0161] Comparative Example 9.

[0162] Different from Example 3, the sex stability regulator was not added.

[0163] Comparative Example 10.

[0164] Different from Example 3, in the preparation of the sex stability regulator, the modified zirconium silicate fiber of S11 was not added.

[0165] Comparative Example 11.

[0166] Different from Example 3, in the preparation of the sex stability regulator, chitosan solution and boron nitride were not added.

[0167] Comparative Example 12.

[0168] Different from Example 3, in the preparation of S11, stirring treatment in sodium silicate solution was not used.

[0169] Test the performance of Examples 1-3 and Comparative Examples 1-12. At the same time, place the product under the condition of 2% sodium chloride salt spray for 24 h, then cool it at -10 °C for 24 h, and finally place it at 70 °C for 24 h. The above is one cycle, and test the salt resistance and thermal-cold stability of the product;

[0170]

[0171]

[0172] It can be seen from Comparative Examples 1-12 and Examples 1-3 that;

[0173] The product of Example 3 has excellent bending strength, electrical conductivity and wear resistance. The performance of the product can be improved in a coordinated manner. At the same time, the product has excellent stability under the conditions of salt resistance and thermal-cold stability;

[0174] If one of the equilibrium agent doped with calcined alumina and the sex stability regulator is not added to the product, the performance of the product deteriorates significantly. By using the two in coordination and synergistic effect, the performance effect of the product is the most obvious;

[0175] In the preparation of the equilibrium agent doped with calcined alumina, the treatment with the aluminum borate whisker leveling solution was not adopted, and the treatment with calcined alumina was not adopted, and the performance of the product showed an obvious deterioration trend. At the same time, in the preparation of the aluminum borate whisker leveling solution, the treatment with the leveling modifier was not adopted, in the preparation of the leveling modifier, the silicon carbide agent was not added, the silicon carbide agent was directly replaced with silicon carbide, in the preparation of the leveling modifier, stearic acid, silane coupling agent KH560 were not added, and in the preparation of the aluminum borate whisker leveling solution, the irradiated aluminum borate whisker treatment was not adopted, and the performance of the product all showed a deterioration trend to varying degrees;

[0176] The performance effect of the product is the most obvious when the aluminum borate whisker leveling solution obtained by the specific method of the present invention is combined with the treatment of calcined alumina. At the same time, in the preparation of the equilibrium agent doped with calcined alumina, the treatment with calcined alumina is not adopted, and the performance of the product deteriorates significantly.

[0177] In the preparation of the property stability regulator, the modified zirconium silicate fiber of S11 was not added, the chitosan solution and boron nitride were not added in the preparation of the property stability regulator, and in the preparation of S11, the stirring treatment in the sodium silicate solution was not adopted, and the performance of the product also showed a deterioration trend. The performance effect of the product is the most significant when the modified zirconium silicate fiber of the present invention and the property stability regulator obtained from the specific raw materials of the present invention are used. Using other methods to replace them is not as obvious as the effect of the present invention.

[0178] Based on the fact that calcined alumina has a greater influence on the product performance trend, the present invention further explores it:

[0179] Experimental Example 1.

[0180] The only difference from Example 3 is that in the preparation of calcined alumina, the temperature was not raised to 215 °C at a rate of 2 °C / min, held for 7.5 min, and then raised to 350 °C at a rate of 3.5 °C / min and held for 3.5 min.

[0181] Experimental Example 2.

[0182] The only difference from Example 3 is that nano-bentonite was not added in the preparation of calcined alumina.

[0183] Experimental Example 3.

[0184] The only difference from Example 3 is that hydrochloric acid dopamine solution was not added in the preparation of calcined alumina.

[0185] Experimental Example 4.

[0186] The only difference from Example 3 is that yttrium nitrate solution was not added.

[0187] Experimental Example 5.

[0188] The only difference from Example 3 is that air-cooled alumina at room temperature was not added.

[0189] Its performance was tested as follows;

[0190]

[0191]

[0192] It can be seen from Experimental Examples 1-5 that in the preparation of calcined alumina, when alumina air-cooled to room temperature was not added, the performance of the product showed a significant deterioration trend. At the same time, when nano-bentonite was not added in the preparation of calcined alumina, the deterioration of the product performance was also obvious. In addition, when hydrochloric acid dopamine solution was not added, yttrium nitrate solution was not added, and the temperature was not raised to 215 °C at a rate of 2 °C / min and held for 7.5 min, and then raised to 350 °C at a rate of 3.5 °C / min for treatment in the preparation of calcined alumina, the performance of the product all showed a deterioration trend. Only the calcined alumina prepared by the specific method of the present invention had the most significant product performance effect, and the use of other methods instead was not as obvious as that of the present invention.

[0193] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, all changes falling within the meaning and scope of the equivalent elements of the claims are intended to be included in the present invention.

[0194] In addition, it should be understood that although this specification is described according to embodiments, not every embodiment only contains an independent technical solution. This narrative way of the specification is only for clarity. Those skilled in the art should regard the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A preparation method of a silver-containing copper-based carbon brush for a traffic vehicle, characterized in that, The following steps are involved: Step 1, weighing the raw materials in parts by weight: 80-82 parts of copper, 5-8 parts of a balance agent doped with calcined alumina, 5-7 parts of a stability regulator, 4-6 parts of tin, 3-5 parts of 500-mesh molybdenum disulfide powder, 1-3 parts of silver, and 4-6 parts of 1000-mesh carbon powder; Step 2, the raw materials in step 1 are mixed thoroughly, and then pressure-formed in a mold, and then sintered and improved. After sintering, demoulding is completed; Step 3, heating the polyethylene wax until it melts, and immersing the brush body processed in step 2 into the melted polyethylene wax at a pressure of 10 MPa for 60 minutes; performing ultrasonic vibration cleaning on the immersed brush body 3 times, and then wiping off excess grease on the surface with oil-absorbing paper, and cooling naturally to obtain a silver-containing copper-based carbon brush; The preparation method of the balance agent doped with calcined alumina is as follows: S01: irradiate the aluminum borate whiskers in a proton irradiation box for 5-10 minutes at a power of 350W, and then the irradiation ends; S02: Stir and mix silicon carbide and 2-5% by mass lanthanum chloride solution in a weight ratio of 2:5 to obtain a silicon carbide agent; 1-2 parts of stearic acid and 1-3 parts of silane coupling agent KH560 are added to 5-8 parts of sodium lignin sulfonate solution, and then 2-4 parts of silicon carbide agent are added and mixed to obtain a leveling modifier; S03: subjecting the irradiated aluminum borate whiskers and the leveling modifier to ultrasonic modification in a weight ratio of 3:7, and completing the ultrasonic modification to obtain an aluminum borate whisker leveling solution; S04: calcined alumina and aluminum borate whisker leveling liquid are mixed in a weight ratio of 5:(2-3) and ball-milled at a ball-milling speed of 1500r / min for 1h. After the ball-milling is completed, the mixture is washed with water and dried to obtain a balancing agent doped with calcined alumina; The preparation method of the stability regulator is: S11: the zirconium silicate fiber is firstly stirred and mixed in a sufficient amount of a 5% by mass potassium permanganate solution, then washed and dried, and the dried zirconium silicate fiber is immersed in a sufficient amount of a 5% by mass sodium silicate solution and stirred, and after the stirring is completed, the fiber is filtered and dried to obtain a modified zirconium silicate fiber; S12: 5-8 parts of modified zirconium silicate fiber, 1-3 parts of 2-4% by mass sodium dodecylbenzene sulfonate solution, 2-5 parts of carboxymethyl cellulose, 6-8 parts of 4% by mass chitosan solution and 2-4 parts of boron nitride are blended and ball-milled at a speed of 1000 r / min for 2 hours. After the ball-milling is completed, the mixture is washed with water, filtered and dried to obtain a stability regulator.

2. The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle according to claim 1, characterized in that, The purity of the copper and tin is not less than 99.5%; the purity of the silver is not less than 99.9%; The holding pressure of the pressure-holding molding is 80 MPa, and the holding time is 10 min; The sintering temperature of the sintering improvement treatment is 850-1000° C., sintering for 2 hours, and then cooling to room temperature at a rate of 2-5° C. / min.

3. The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle according to claim 1, characterized in that, The mass fraction of the sodium lignin sulfonate solution is 4-6%.

4. The preparation method of a silver-containing copper-based carbon brush for a traffic vehicle according to claim 1, characterized in that, The ultrasonic power of the ultrasonic modification treatment is 350-400W, and the ultrasonic time is 20-30min.

5. The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle according to claim 1, characterized in that, The preparation method of the calcined alumina is: The alumina is first heated to 210 - 220 °C at a rate of 1 - 3 °C / min, held for 5 - 10 min, then heated to 350 °C at a rate of 2 - 5 °C / min, and held for another 2 - 5 min, and finally air-cooled to room temperature; 5 - 8 parts of alumina air-cooled to room temperature, 2 - 4 parts of nano-bentonite, 1 - 2 parts of hydrochloric acid dopamine solution and 5 - 8 parts of yttrium nitrate solution are mixed and ball-milled. The ball-milling speed is 1000 r / min, and the ball-milling is carried out for 2 h. After the ball-milling is completed, it is washed with water and dried to obtain calcined alumina.

6. The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle according to claim 5, characterized in that, The mass fraction of the hydrochloric acid dopamine solution is 2 - 4%; the mass fraction of the yttrium nitrate solution is 3 - 6%.

7. The preparation method of a silver-containing copper-based carbon brush for a transportation vehicle according to claim 1, characterized in that, The stirring speed of the stirring treatment in S11 is 450 - 500 r / min, and the stirring is carried out for 20 - 30 min.

8. A silver-containing copper-based carbon brush for a transportation vehicle prepared by the preparation method of the silver-containing copper-based carbon brush according to any one of claims 1 - 7.

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