阅读说明：本技术 一种螺旋纳米碳纤维增强受电弓滑板的制备方法 (Preparation method of spiral carbon nanofiber reinforced pantograph slide plate ) 是由 龚勇 刘平 李琳 涂川俊 鄢鹏 于 2021-09-07 设计创作，主要内容包括：本发明公开了一种螺旋纳米碳纤维增强受电弓滑板的制备方法,包括以下步骤：1)将碳化硅粉、沥青焦粉和石墨粉混合,再加入螺旋纳米碳纤维和铜粉混合料继续混合,加入熔化的高温沥青,将均匀混合后的物料倒入模具中模压成型,将冷却后的毛坯进行焙烧得到碳滑板；2)将步骤1)得到的碳滑板置于与浸渍罐相连的真空罐中抽真空,预热处理,通入空气冷却后,再次进行抽真空,将碳滑板放入装有铜液的浸渍罐中关闭浸渍罐,在加压状态下保温,使铜液渗透浸入碳滑板孔隙中,泄压后将碳滑板取出,冷却后得到所述受电弓滑板。本发明选用的组分中加入了螺旋纳米碳纤维和铜粉混合料,螺旋纳米碳纤维的特殊结构能与骨料更好的结合,增强滑板的综合性能。(The invention discloses a preparation method of a spiral carbon nanofiber reinforced pantograph slide plate, which comprises the following steps: 1) mixing silicon carbide powder, asphalt coke powder and graphite powder, adding the mixture of the spiral carbon nanofibers and the copper powder, continuously mixing, adding molten high-temperature asphalt, pouring the uniformly mixed materials into a mold for molding, and roasting the cooled blank to obtain the carbon slide plate; 2) placing the carbon sliding plate obtained in the step 1) in a vacuum tank connected with an impregnation tank, vacuumizing, preheating, introducing air for cooling, vacuumizing again, placing the carbon sliding plate in the impregnation tank filled with copper liquid, closing the impregnation tank, preserving heat under a pressurized state to enable the copper liquid to penetrate and immerse in pores of the carbon sliding plate, taking out the carbon sliding plate after pressure relief, and cooling to obtain the pantograph sliding plate. According to the invention, the spiral carbon nanofiber and copper powder mixture is added into the selected components, so that the special structure of the spiral carbon nanofiber can be better combined with aggregate, and the comprehensive performance of the sliding plate is enhanced.)

1. A preparation method of a spiral carbon nanofiber reinforced pantograph slide plate is characterized by comprising the following steps:

1) mixing silicon carbide powder, asphalt coke powder and graphite powder, adding the mixture of spiral carbon nanofibers and copper powder, continuously mixing, adding molten high-temperature asphalt, uniformly mixing at 130-170 ℃ for 1.5-2.5 hours, pouring the mixed material into a mold, performing compression molding, naturally cooling to obtain a carbon slide plate blank, and roasting the blank to obtain the carbon slide plate;

the raw materials are prepared according to the following parts by weight: 5-15 parts of silicon carbide powder, 50-60 parts of asphalt coke powder, 5-10 parts of graphite powder, 25-30 parts of high-temperature asphalt and 5-10 parts of a mixture of spiral carbon nanofiber and copper powder;

2) placing the carbon sliding plate obtained in the step 1) in a vacuum tank connected with an impregnation tank for vacuumizing, preheating for 2-3 hours at 900-1100 ℃, introducing air for cooling, vacuumizing again, placing the carbon sliding plate in the impregnation tank filled with copper liquid, closing the impregnation tank, introducing nitrogen and pressurizing to 100kg/cm²And preserving the temperature for 3-5 minutes under the pressure to enable the copper liquid to penetrate and immerse into pores of the carbon slide plate, taking out the carbon slide plate after pressure relief, and cooling to obtain the pantograph slide plate.

2. The method for preparing a pantograph pan reinforced with carbon nanofibers according to claim 1, wherein in step 1), the carbon nanofibers are pretreated by a modified Hummers method and then used.

3. The preparation method of the spiral carbon nanofiber reinforced pantograph pan according to claim 1, wherein in the step 1), the spiral carbon nanofibers are prepared into 0.5-1.5 g/mL of dispersion liquid, sodium dodecyl benzene sulfonate with the same mass as the spiral carbon nanofibers is added and then stirred uniformly, copper nanoparticles with the same mass as the spiral carbon nanofibers are added and ultrasonically treated in an ultrasonic cleaner to dry powder, and a uniformly dispersed mixture of the spiral carbon nanofibers and the copper nanoparticles is obtained.

4. The method for preparing a pantograph pan reinforced with carbon nanofibers according to claim 1, wherein in step 2), before preheating, a vacuum tank is evacuated to a vacuum degree of 100 Pa.

5. The method for preparing the pantograph pan with the spiral nano carbon fiber reinforced according to claim 1, wherein in the step 2), after cooling, the pantograph pan with the spiral nano carbon fiber reinforced is continuously pumped to a vacuum degree of 100 Pa.

Technical Field

The invention relates to the technical field of pantograph slide plates of electric locomotives, in particular to a preparation method of a spiral carbon nanofiber reinforced pantograph slide plate.

Background

The pantograph slide plate is a key part for obtaining electric energy by an electric locomotive, is in direct contact with a contact net lead to obtain current, and the current is generally 100-1000A. The pantograph slide plate runs at the same speed as the electric locomotive and is exposed to the complex and severe environment outside, and certain self-lubricating property and abrasion reduction property are required for the pantograph slide plate. Therefore, the performance of the sliding plate is related to the driving safety of the electric locomotive, and a serious safety accident can be caused once the sliding plate fails.

With the development of high speed railways, the requirements for the sliding plate are more and more demanding. The traditional carbon sliding plate has the advantages of large self abrasion, short service life, low mechanical strength, poor impact toughness resistance, easy fracture and block falling phenomena due to the fact that interfaces are connected together through mechanical interlocking, and very easy serious bow net accidents. Meanwhile, the traditional sliding plate metal dipping process cannot completely fill the pores in the carbon sliding plate, and gas in the carbon sliding plate is compressed in the sliding plate, so that the overall performance of the sliding plate is influenced.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide a preparation method of a spiral carbon nanofiber reinforced pantograph pan, so as to solve the problems of large abrasion of the pantograph pan, low mechanical strength, poor impact toughness and poor safety performance in the prior art.

In order to solve the technical problems, the invention adopts the following technical scheme:

a preparation method of a spiral carbon nanofiber reinforced pantograph slide plate comprises the following steps:

1) mixing silicon carbide powder, asphalt coke powder and graphite powder, adding the mixture of spiral carbon nanofibers and copper powder, continuously mixing, adding molten high-temperature asphalt, uniformly mixing at 130-170 ℃ for 1.5-2.5 hours, pouring the mixed material into a mold, performing compression molding, naturally cooling to obtain a carbon slide plate blank, and roasting the blank to obtain the carbon slide plate;

the raw materials are prepared according to the following parts by weight: 5-15 parts of silicon carbide powder, 50-60 parts of asphalt coke powder, 5-10 parts of graphite powder, 25-30 parts of high-temperature asphalt and 5-10 parts of a mixture of spiral carbon nanofiber and copper powder;

2) and (2) placing the carbon slide plate obtained in the step 1) in a vacuum tank connected with an impregnation tank for vacuumizing, preheating for 2-3 hours at 900-1100 ℃, introducing air for cooling, vacuumizing again, placing the carbon slide plate in the impregnation tank filled with copper liquid, closing the impregnation tank, introducing nitrogen for pressurizing to 100kg/cm2, preserving heat for 3-5 minutes under the pressure to enable the copper liquid to permeate and immerse in pores of the carbon slide plate, taking out the carbon slide plate after pressure relief, and cooling to obtain the pantograph slide plate.

Compared with the prior art, the invention has the following beneficial effects:

1. according to the invention, the spiral carbon nanofibers have the excellent properties of high strength, heat resistance, high temperature resistance, corrosion resistance, abrasion resistance, electric conduction and the like of common straight carbon fibers, the special spiral structure of the spiral carbon nanofibers can be wound with more master batches, the mechanical property of the sliding plate is enhanced, the uniformly dispersed spiral carbon nanofibers in the sliding plate form a three-dimensional conductive network, and the resistivity of the sliding plate is reduced; the raw material components are added with the spiral carbon nanofiber and the copper powder mixture for preparation, the mixture can be well dispersed, the special spiral structure of the spiral carbon nanofiber can be better combined with aggregate, and the comprehensive performance of the sliding plate is enhanced.

2. The spiral carbon nanofiber modified by the sodium dodecyl benzene sulfonate has multiple surface active points, and the hydroxyl, carboxyl, dodecyl benzene sulfonic acid groups and the like on the surface can enhance the combination of the spiral carbon nanofiber and a copper matrix, so that the strength of the sliding plate is enhanced.

3. According to the invention, the carbon sliding plate is vacuumized to remove gas in the sliding plate before the copper leaching process, partial oxidation of the surface of the carbon sliding plate at a high temperature of 1000 ℃ during preheating is avoided, and meanwhile, the phenomenon that the gas is compressed into the sliding plate in the copper leaching liquid process, so that insufficient copper leaching is caused and the performance of the sliding plate is influenced is avoided.

Detailed Description

The present invention will be further described with reference to the following examples.

Preparation method of spiral carbon nanofiber reinforced pantograph slide plate

1) Mixing silicon carbide powder, asphalt coke powder and graphite powder for 60min, adding the mixture of the spiral carbon nanofibers and the copper powder, continuously mixing for 30min, adding molten high-temperature asphalt, uniformly mixing for 2h at 150 ℃, pouring the mixed material into a mold for compression molding, naturally cooling to obtain a carbon slide plate blank, and roasting the blank to obtain the carbon slide plate;

the raw materials are prepared according to the following parts by weight: 5-15 parts of silicon carbide powder, 50-60 parts of asphalt coke powder, 5-10 parts of graphite powder, 25-30 parts of high-temperature asphalt and 5-10 parts of a mixture of spiral carbon nanofiber and copper powder.

Wherein, the spiral nanometer carbon fiber is used after being pretreated by an improved Hummers method. Adding spiral carbon nanofiber into aqua regia, performing ultrasonic treatment for 60min under 210W, placing the solution in an ice water bath, stirring for 4 hours, and slowly adding KMnO₄And stirred for 4 hours; 50mL of deionized water and 5mLH were added₂O₂And filtering the suspension, washing the suspension to be neutral by using deionized water, and drying the suspension in a drying oven at 80 ℃ for 24 hours to obtain the pretreated spiral carbon nanofiber. Spiral carbon nanofiber and KMnO₄The mass ratio of (A) to (B) is 1: 2.

Preparing the spiral carbon nanofibers into 1g/mL of dispersion liquid (water or ethanol can be used as a solvent for preparing the dispersion liquid), adding sodium dodecyl benzene sulfonate with the same mass as the spiral carbon nanofibers, uniformly stirring, adding copper nanoparticles with the same mass as the spiral carbon nanofibers, and ultrasonically treating the mixture in an ultrasonic cleaner to dry powder to obtain a uniformly dispersed mixture of the spiral carbon nanofibers and the copper powder. The spiral carbon nanofiber modified by the sodium dodecyl benzene sulfonate has a plurality of surface active points, and the combination of the spiral carbon nanofiber and a copper matrix can be enhanced by the hydroxyl, carboxyl, dodecyl benzene sulfonic acid groups and the like on the surface, so that the strength of the sliding plate is enhanced.

2) Placing the carbon sliding plate obtained in the step 1) in a vacuum tank connected with an impregnation tank, pumping until the vacuum degree is 100Pa, and pumping before preheating to avoid the carbon sliding plate from being oxidized at high temperature of 1000 DEG CPreheat 2~3 hours down, let in after the air cooling, carry out the evacuation once more, it is 100Pa to take out to the vacuum degree, the evacuation can take out the gas in the carbon slide hole once more after preheating, make during copper liquid can be more abundant entering carbon slide when soaking copper, gas in the carbon slide is compressed in the slide when avoiding soaking copper, because gas is very easily compressed to the carbon slide in when soaking copper, this can reduce the rupture strength and the compressive strength of slide by a wide margin, still can lead to the easy cracked risk of carbon slide appearance even. Putting the carbon slide plate into an impregnation tank filled with copper liquid, closing the impregnation tank, introducing nitrogen gas, and pressurizing to 100kg/cm²And preserving the temperature for 3-5 minutes under the pressure to enable the copper liquid to penetrate and immerse into pores of the carbon slide plate, taking out the carbon slide plate after pressure relief, and cooling to obtain the pantograph slide plate.

When the existing pantograph carbon slide plate and the preparation method thereof are researched, the carbon slide plate prepared by the prior art is low in mechanical strength and poor in impact toughness, so that the carbon slide plate is seriously abraded in the actual use process, the service life of the carbon slide plate is short, the carbon slide plates are connected together through mechanical interlocking, the phenomena of breakage and block falling are easily caused, and serious pantograph net accidents are easily caused. In order to solve the problems, the invention improves the raw material components of the carbon sliding plate, adopts different carbon raw materials to prepare the carbon sliding plate, and measures the performance of the carbon sliding plate. After intensive research, the spiral carbon nanofiber has the effect brought by the special structure of the spiral carbon nanofiber, and the spiral carbon nanofiber has a special spiral structure besides excellent performances of high strength, heat resistance, high temperature resistance, corrosion resistance, abrasion resistance, electric conduction and the like of common straight carbon fibers, and the special spiral structure enables the spiral carbon nanofiber to be wound with more master batches, so that the mechanical property of the carbon sliding plate is improved; meanwhile, the dispersibility of the common straight carbon fiber in the carbon sliding plate is poor in experiments, and the observation shows that compared with the common straight carbon fiber, the spiral nano carbon fiber is more uniformly dispersed in the carbon sliding plate, a three-dimensional conductive network can be formed in the carbon sliding plate, the resistivity of the carbon sliding plate is further reduced, and the carbon sliding plate has more excellent conductivity. The invention also unexpectedly discovers after intensive research that the addition of the sodium dodecyl benzene sulfonate can further improve the performance of the carbon sliding plate, the spiral carbon nanofibers and the sodium dodecyl benzene sulfonate are uniformly mixed in advance and then are mixed with the copper powder to prepare the carbon sliding plate, the obtained carbon sliding plate has very obvious improvement on the properties such as resistivity, impact toughness, breaking strength, compressive strength and the like, and further research shows that the spiral carbon nanofibers modified by the sodium dodecyl benzene sulfonate can increase the surface active points of the spiral carbon nanofibers, and the combination of the spiral carbon nanofibers and a copper matrix can be enhanced by the hydroxyl, carboxyl, dodecyl benzene sulfonic acid and other groups on the surface of the spiral carbon nanofibers, which is the very obvious improvement on the breaking strength and compressive strength of the carbon sliding plate on the performance of the carbon sliding plate. When the preparation technology of the carbon sliding plate is researched, the carbon sliding plate cannot be completely filled with metal in the step of metal immersion, and the observation shows that a certain number of bubbles are formed inside the carbon sliding plate after the existing metal immersion technology, and the carbon sliding plate is provided with pores, so that a large number of gases are remained in the pores, and the gases cannot be discharged and are compressed into the carbon sliding plate by molten metal in the process of metal immersion, so that the overall performance of the carbon sliding plate is reduced. Therefore, the invention considers the condition of adding vacuum pumping in the process of metal immersion, and unexpectedly discovers that the surface of the carbon sliding plate can generate partial oxidation phenomenon at the high temperature of 1000 ℃ in the actual preparation process, the vacuum pumping treatment before preheating can avoid the phenomenon, and the vacuum pumping after preheating can pump out the gas in the pores of the carbon sliding plate, so that the copper liquid can more fully enter the carbon sliding plate in the process of copper liquid immersion, and the gas remained in the pores is prevented from being compressed into the carbon sliding plate in the process, thereby causing bad influence on the overall performance of the carbon sliding plate.

Second, examples and comparative examples

By adopting the method, the raw materials in the table 1 are mixed to prepare the following examples 1-5.

TABLE 1 (in the following, parts by weight)

Examples	Silicon carbide powder	Asphalt coke powder	Graphite powder	High temperature asphalt	Mixture of spiral carbon nanofiber and copper powder
						1	5	50	5	25	5
2	5	60	10	25	5
						3	10	50	10	25	6
4	10	60	5	30	8
						5	15	60	10	30	10

By adopting the method, comparative examples 1-2 were prepared according to the raw material ratios in table 2.

TABLE 2

Comparative example	Silicon carbide powder	Asphalt coke powder	Graphite powder	High temperature asphalt	Kind of carbon fiber	Carbon fiber and copper powder mixture
							1	5	50	5	25	Ordinary carbon fiber (without sodium dodecylbenzenesulfonate treatment)	5
2	5	50	5	25	Spiral carbon nanofibers (without sodium dodecyl benzene sulfonate treatment)	5

Comparative example 3 is identical to example 1 in the material ratio and preparation method, except that comparative example 3 is not vacuumized.

The performance of examples 1-5 and comparative examples were tested. The test criteria were: TBT 1842.2-2016 pantograph slide plate part 2: carbon base composite material slide.

TABLE 3 Properties of composite skateboards prepared in examples 1-5

Sample (I)	Bulk Density (g/cm)3）	Resistivity (mu omega M)	Impact toughness (J/cm)2）	Flexural strength (MPa)	Compressive strength (MPa)
						Example 1	2.8	5.7	0.21	91	198
Example 2	2.8	4.9	0.21	90	201
						Example 3	3.1	5.1	0.23	94	210
Example 4	2.9	5.2	0.25	92	202
						Example 5	3.0	5.5	0.26	91	199
Comparative example 1	2.9	6.8	0.20	83	186
						Comparative example 2	2.8	6.1	0.21	86	190
Comparative example 3	2.9	6.4	0.20	81	189

It can be seen from the combined analysis of tables 1-3 that comparative example 1 using common carbon fibers is compared with example 1, the resistivity is significantly improved, the conductivity of comparative example 1 is significantly reduced, and the flexural strength and compressive strength are both significantly reduced compared with example 1, which is exactly because the spiral carbon nanofibers have a special spiral structure, the special spiral structure can wind more master batches, the mechanical property of the carbon sliding plate is significantly enhanced, the spiral carbon nanofibers uniformly dispersed in the carbon sliding plate can form a stable three-dimensional conductive network, and the resistivity of the sliding plate is greatly reduced. Meanwhile, the embodiment also adopts the sodium dodecyl benzene sulfonate to modify the spiral carbon nanofibers, so that the surface active points are increased, the hydroxyl, carboxyl, dodecyl benzene sulfonic acid groups and the like on the surfaces of the spiral carbon nanofibers can enhance the combination of the spiral carbon nanofibers and the copper matrix, and further enhance the strength of the skateboard, and as is obvious from the embodiment 1 and the comparative example 2, the electrical conductivity, the flexural strength and the compressive strength of the embodiment 1 added with the sodium dodecyl benzene sulfonate are all superior to those of the comparative example 2, although the spiral carbon nanofibers have special spiral structures which can obviously enhance the mechanical properties of the carbon skateboard, and the electrical conductivity, the flexural strength and the compressive strength of the comparative example 2 are superior to those of the comparative example 1, but the improvement effect on the mechanical properties of the carbon skateboard is still very limited without matching with the use of the sodium dodecyl benzene sulfonate. In the research, partial oxidation of the surface of the carbon sliding plate at the high temperature of 1000 ℃ can be caused by no vacuumizing before preheating, gas can be compressed into the carbon sliding plate during copper soaking, the breaking strength and the compressive strength of the carbon sliding plate are greatly reduced, the breaking strength and the compressive strength of the comparative example 3 are remarkably reduced compared with those of the example 1 due to the fact that vacuumizing is not performed, and meanwhile, the comparative example 3 is found to be more prone to fracture than other examples and comparative examples in practical application and has serious potential safety hazards.

According to the invention, the spiral carbon nanofibers have the excellent properties of high strength, heat resistance, high temperature resistance, corrosion resistance, abrasion resistance, electric conduction and the like of common straight carbon fibers, have special spiral structures, can be wound with more master batches, enhance the mechanical property of the sliding plate, form a three-dimensional electric conduction network by uniformly dispersing the spiral carbon nanofibers in the sliding plate, and reduce the resistivity of the sliding plate; the raw material components are added with the spiral carbon nanofiber and copper powder mixture for preparation, the mixture can be well dispersed, the special spiral structure of the spiral carbon nanofiber can be better combined with aggregate, and the comprehensive performance of the sliding plate is enhanced; the invention also adopts the sodium dodecyl benzene sulfonate modified spiral carbon nanofiber with more active points on the surface, and hydroxyl, carboxyl, dodecyl benzene sulfonic acid groups and the like on the surface can enhance the combination of the spiral carbon nanofiber and the copper matrix, thereby enhancing the strength of the skateboard. According to the invention, the carbon sliding plate is vacuumized to remove gas in the sliding plate before the copper leaching process, partial oxidation of the surface of the carbon sliding plate at a high temperature of 1000 ℃ during preheating is avoided, and meanwhile, the phenomenon that the gas is compressed into the sliding plate in the copper leaching liquid process, so that insufficient copper leaching is caused and the performance of the sliding plate is influenced is avoided.

Finally, it should be noted that the above embodiments are only used for illustrating the technical solutions of the present invention and not for limiting the technical solutions, and those skilled in the art should understand that modifications or equivalent substitutions can be made on the technical solutions of the present invention without departing from the spirit and scope of the technical solutions, and all that should be covered by the claims of the present invention.