GRAPHENE COPPER PANTOGRAPH PAN MATERIAL FOR HIGH-SPEED TRAINS AND PREPARATION METHOD THEREOF

Abstract

The present invention provides a graphene copper pantograph pan material for high-speed trains and a preparation method thereof, and the pan uses graphene as a reinforcing material, copper and iron as base materials, coke powder and graphite fiber as self-lubricating wear-resistant materials, and titanium, tungsten and molybdenum as additives. After being uniformly mixed, all the components are directly formed by hot pressing. The pantograph pan prepared by the present invention has the advantages of favorable electrical conductivity, wear resistance, impact resistance, ablation resistance and the like, and has little wear to overhead lines. The pan not only has simple preparation process, but also has much better performance than the conventional carbon pans and metal impregnated pans. The pan material is not only suitable for pantograph pans for high-speed trains such as high-speed rails and bullet trains, but also suitable for electric contact materials for low-speed trains such as subways.

Claims

1. A method for preparing a graphene copper pantograph pan material for high-speed trains, wherein the method comprises the following steps: (1) first, uniformly dispersing graphene, additive and carbon nanotube in a polyvinyl alcohol solution with the concentration of 8.5% according to the mass ratio of the components of the graphene copper pantograph pan material, wherein the mass ratio of graphene to polyvinyl alcohol is 1:10, then adding copper powder, iron powder, coke and graphite fiber to the mixed solution in sequence, and stirring uniformly; the graphene copper pantograph pan material comprises the following components by mass ratio: wherein 2.0-11.0 wt % of graphene, 30.5-60.5 wt % of copper powder, 1.0-19.0 wt % of iron powder, 8.0-37.0 wt % of coke, 1.0-5.0 wt % of carbon nanotube, 0.4-6.2 wt % of graphite fiber and 0.06-0.25 wt % of additive; the additive is formed by mixing titanium powder of 600-800 meshes, tungsten powder of 800-1200 meshes and molybdenum powder of 900-1200 meshes, and the mass ration of titanium powder to tungsten powder to molybdenum powder is 1:3:5; (2) drying the mixed solution prepared in step (1) in vacuum, wherein the drying temperature is 30° C.-50° C.; (3) taking out the dried material and placing in the sample hot-pressing groove of a hot press for direct vacuum hot pressing, wherein the pressure intensity for hot pressing is 40-120 MPa, the temperature is 850° C.-1200° C., and the holding time is 8-20 min, thus obtaining a graphene copper pantograph pan material.

2. (canceled)

3. The method for preparing the graphene copper pantograph pan material for high-speed trains according to claim 1, wherein the particle size of the copper powder used is 400-600 meshes, and the particle size of the iron powder is 900-1200 meshes.

4. The method for preparing the graphene copper pantograph pan material for high-speed trains according to claim 1, wherein the carbon nanotube used is single-wall or multi-wall, with the diameter of 2-10 nm and the length of 0.5-8 μm.

5. The method for preparing the graphene copper pantograph pan material for high-speed trains according to claim 1, wherein the particle size of the coke used is 100-400 meshes, and the graphite fiber is high-strength fiber, with the diameter of 4-8 μm and the length of 0.5-3 cm.

6. (canceled)

Description

DETAILED DESCRIPTION

Embodiment 1

[0018] (1) First, uniformly dispersing 2 wt % of graphene, 0.20 wt % of additive and 3 wt % of carbon nanotube (with the diameter of about 3 nm and the length of about 0.5 μm) in a polyvinyl alcohol solution, then adding 57 wt % of copper powder of 400 meshes, 17 wt % of iron powder of 900 meshes, 20.8 wt % of coke of 400 meshes and 6 wt % of graphite fiber (with the diameter of about 4 μm and the length of about 2 cm) to the solution in sequence, and stirring uniformly.

[0019] (2) Drying the mixture in vacuum, wherein the drying temperature is 30° C.

[0020] (3) Taking out the dried material and placing in the sample hot-pressing groove of a hot press for direct vacuum hot pressing, wherein the pressure intensity for hot pressing is 50 MPa, the hot pressing temperature is 1100° C., and the holding time is 12 min.

[0021] The prepared pan has the density of 4.27 g/cm.sup.3, the electrical resistivity of 0.12 μΩ.Math.m, the impact toughness of 5.90 J/cm.sup.2, the bending strength of 381 MPa, the friction coefficient of 0.052, and the compressive strength of 370 MPa.

Embodiment 2

[0022] (1) First, uniformly dispersing 5 wt % of graphene, 0.10 wt % of additive and 5 wt % of carbon nanotube (with the diameter of about 4 nm and the length of about 1 μm) in a polyvinyl alcohol solution, then adding 53 wt % of copper powder of 500 meshes, 15 wt % of iron powder of 1100 meshes, 19.9 wt % of coke of 200 meshes and 2 wt % of graphite fiber (with the diameter of about 5 μm and the length of about 3 cm) to the solution in sequence, and stirring uniformly.

[0023] (2) Drying the mixture in vacuum, wherein the drying temperature is 30° C.

[0024] (3) Taking out the dried material and placing in the sample hot-pressing groove of a hot press for direct vacuum hot pressing, wherein the pressure intensity for hot pressing is 80 MPa, the hot pressing temperature is 1000° C., and the holding time is 9 min.

[0025] The prepared pan has the density of 4.21 g/cm.sup.3, the electrical resistivity of 0.14 μΩ.Math.m, the impact toughness of 5.72 J/cm.sup.2, the bending strength of 370 MPa, the friction coefficient of 0.045, and the compressive strength of 360 MPa.

Embodiment 3

[0026] (1) First, uniformly dispersing 8 wt % of graphene, 0.08 wt % of additive and 4 wt % of carbon nanotube (with the diameter of about 5 nm and the length of about 2 μm) in a polyvinyl alcohol solution, then adding 50 wt % of copper powder of 600 meshes, 12 wt % of iron powder of 1200 meshes, 23 wt % of coke of 300 meshes and 2.92 wt % of graphite fiber (with the diameter of about 6 μm and the length of about 1 cm) to the solution in sequence, and stirring uniformly.

[0027] (2) Drying the mixture in vacuum, wherein the drying temperature is 30° C.

[0028] (3) Taking out the dried material and placing in the sample hot-pressing groove of a hot press for direct vacuum hot pressing, wherein the pressure intensity for hot pressing is 100 MPa, the hot pressing temperature is 1100° C., and the holding time is 8 min.

[0029] The prepared pan has the density of 4.17 g/cm.sup.3, the electrical resistivity of 0.16 μΩ.Math.m, the impact toughness of 5.50 J/cm.sup.2, the bending strength of 361 MPa, the friction coefficient of 0.040, and the compressive strength of 349 MPa.

Embodiment 4

[0030] (1) First, uniformly dispersing 10 wt % of graphene, 0.12 wt % of additive and 2 wt % of carbon nanotube (with the diameter of about 8 nm and the length of about 6 μm), in a polyvinyl alcohol solution, then adding 48 wt % of copper powder of 600 meshes, 10 wt % of iron powder of 1000 meshes, 28 wt % of coke of 100 meshes and 1.88 wt % of graphite fiber (with the diameter of 8 about μm and the length of about 0.5 cm) to the solution in sequence, and stirring uniformly.

[0031] (2) Drying the mixture in vacuum, wherein the drying temperature is 30° C.

[0032] (3) Taking out the dried material and placing in the sample hot-pressing groove of a hot press for direct vacuum hot pressing, wherein the pressure intensity for hot pressing is 120 MPa, the hot pressing temperature is 900° C., and the holding time is 11 min.

[0033] The prepared pan has the density of 4.11 g/cm.sup.3, the electrical resistivity of 0.18 μΩ.Math.m, the impact toughness of 5.35 J/cm2, the bending strength of 347 MPa, the friction coefficient of 0.032, and the compressive strength of 337 MPa.