WO2012055155A1

WO2012055155A1 - Method for manufacturing carbon nanotube composite transmission wire

Info

Publication number: WO2012055155A1
Application number: PCT/CN2011/001592
Authority: WO
Inventors: 李波; 骆珊; 邢丽; 夏春; 刘鸽平; 黄春平
Original assignee: 江西省电力科学研究院; 南昌航空大学
Priority date: 2010-10-28
Filing date: 2011-09-19
Publication date: 2012-05-03
Also published as: CN101948988A

Abstract

A method for manufacturing a carbon nanotube composite transmission wire, comprising filling a multiwalled carbon nanotube powder accounting for 1% to 7% of the total mass into small holes uniformly drilled on electrotechnical aluminium blocks; stacking two aluminium blocks in which the multiwalled carbon nanotube powder is filled inversely by using a blind-hole method; after the two aluminium blocks are prepared into a composite material through a friction extrusion process, carrying out tandem rolling and drawing the composite material, so as to fabricate the composite material into a required round wire of carbon nanotube/aluminum based composite material; and finally, stranding the round wire by a wire twisting machine, and then through a back-twisting stress eliminating device, obtaining a single-stranded carbon nanotube composite transmission wire. The present invention has the advantages that: 1) the coefficient of linear expansion of the wire is small, and the thermal deformation resistance is strong, so as to reduce the influence of the temperature on sag change, improve the sag characteristics, improve the safety of overhead lines, and reduce the construction cost of the lines; 2) the method is helpful to improve the conductivity of the wire along the line, and further reduce the transmission losses; and 3) the process is relatively simple, and the loosening and skid and the like between a composite core and an aluminium strand caused by various reasons are prevented.

Description

Method for manufacturing carbon nanotube composite transmission wire

The present invention relates to a method of manufacturing a composite transmission wire, and more particularly to a method of manufacturing a carbon nanotube composite transmission wire.

Background technique

The transmission lines of the traditional overhead lines are mostly steel-cored aluminum stranded wires. There are many problems in practical use: For example: 1) The reinforcing steel core greatly increases the weight of the wires, so it is necessary to have a short span between the overhead line towers or Strengthen the strength of the tower, otherwise the load capacity of the tower is not enough, so the line cost increases; 2) the existing magnetic loss and thermal effect make the transmission loss of the line large; 3) the linear expansion coefficient of the steel core, the change of the working condition makes the arc of the wire The vertical variation makes the insulated space corridor of the overhead line large; 4) The electrochemical corrosion between the aluminum wire and the galvanized steel core reduces the service life of the wire.

With the rapid development of China's economy, the construction of the power industry has shown a leaps and bounds, and higher requirements have been placed on overhead transmission lines. In order to overcome the defects of steel-cored aluminum stranded wire, carbon fiber composite core wire has been appeared, such as Chinese patent CN1649718, CN201237921, etc., replacing the traditional steel core with carbon fiber reinforced resin matrix composite material, which has high specific strength, high temperature resistance and fatigue resistance. The characteristics of low transmission and small coefficient of linear expansion are increasingly prominent in transmission lines. However, these types of wires still use traditional aluminum-based material strands, and the comprehensive properties such as toughness and electrical conductivity are still not satisfactory.

For fiber reinforced composites, a key factor in determining their performance is the aspect ratio. Carbon nanotubes, as one-dimensional nanomaterials, have a large aspect ratio (generally above 1000:1), making them ideal for use as tough carbon fibers. They are far superior to any fiber in strength and toughness, so they are considered to be the future." Super Fiber", the application of carbon nanotubes in transmission wires, from a theoretical point of view, far exceeds the performance of carbon fiber composite core wires, and carbon nanotubes can be directly added to the aluminum matrix to improve its overall performance. but, It is related to the physical and chemical properties inherent in the nanophase. The preparation of nanophase-reinforced composite materials is more complicated and more difficult than the preparation of ordinary composite materials. For example, the preparation of carbon nanotube/aluminum matrix composites at home and abroad mainly uses powder metallurgy, melt impregnation, in-situ synthesis, high energy ball milling, rapid solidification, electroless plating, plasma spray molding, etc. These methods require pre-preparation of a powder mixture of carbon nanotubes and an aluminum matrix. The dispersion of carbon nanotubes in the matrix is restricted, and high-energy ball milling and the like also cause damage to the perfect structure of the carbon nanotubes, thereby weakening the composite material. performance.

Summary of the invention

The object of the present invention is to provide a method for manufacturing a carbon nanotube composite transmission wire, wherein the prepared single-strand transmission wire aluminum matrix has fine crystal grains, and the carbon nanotubes are dispersed and oriented along the line, which is beneficial to the carbon nanotube composite material. The advantages are to improve the toughness of the aluminum wire and improve the conductivity along the line, 'reducing transmission loss and so on.

The invention is realized in that the multi-wall carbon nanotube powder which accounts for 1% to 7% of the total mass is filled in the evenly drilled small holes on the electric aluminum block, and the two pieces of multi-wall carbon nano-added have been added. The aluminum blocks of the tube powder are laminated together in a opposite manner in a blind hole manner, so that the multi-walled carbon nanotube powder can be wrapped therein, and then formed by a friction extrusion process, that is, a high-speed rotating friction head and a periphery of the friction head are formed in the middle. A metal flow channel with small gaps is inserted into a high-speed rotating friction head into an aluminum block to which multi-walled carbon nanotube powder has been added. Under the extrusion of the extruded rod, the aluminum block to which the multi-walled carbon nanotube powder has been added is extruded. The friction head is broken through the metal flow passage, the rotation speed of the friction head is 480-720r/min, and the extrusion speed of the extrusion rod is 24-36mm/min, and the carbon nanotube/aluminum composite material is obtained, and the carbon nanotube/aluminum is obtained. The composite material enters the continuous rolling mill and is continuously rolled into a rod. The temperature of the composite material is 500 ° C ~ 60 (rC, the rolling temperature is 150 ° C ~ 350 ° C, after continuous rolling on a continuous, high-speed aluminum alloy wire drawing machine Pull wire, pull speed is 20-30m/s After 13 passes of the wire, the required carbon nanotube/aluminum matrix composite round wire is drawn, and finally, it is twisted on the stranding machine, and the single-strand carbon nanotube composite power transmission is obtained through the anti-twisting and stress-relieving device. Wire. The manufacturing process of the inventive carbon nanotube composite transmission wire is shown in FIG. 1 .

The advantages of the invention are as follows: 1) Friction extrusion is beneficial to the composite of carbon nanotubes and matrix metal, so that it is uniformly dispersed in the matrix, which can greatly improve the mechanical and thermal properties of the material, and the aluminum matrix undergoes frictional extrusion, crystal The grain is refined, which is also beneficial to the improvement of strength and toughness. Therefore, it is not necessary to use steel core or composite core reinforcement to improve the strength of the wire, and the weight of the wire can be greatly reduced. At the same time, the thermal effect caused by the magnetic loss of the steel core wire can be overcome and eliminated. Bimetallic corrosion between aluminum wire and galvanized steel core, reducing transmission loss and improving corrosion resistance of wire; Wire wire expansion coefficient is small, resistance to thermal deformation is strong, can reduce the influence of temperature on sag change, improve sag characteristics Improve the safety of overhead lines and reduce the cost of line construction;

2) After continuous rolling and multi-pass wire, it helps the carbon nanotubes to be oriented in the axial direction. Based on the superconductivity of carbon nanotubes and the anisotropy of the electrical conductivity of the composite, it is beneficial to improve the conductance along the wire. Rate, further reduce transmission loss; 3) Different from most carbon fiber composite core transmission wires, carbon fiber resin-based composite core, carbon nanotubes are directly combined with aluminum matrix, the process is relatively simple, there will be no composite core and aluminum strand due to various kinds The reason is loose, slipping and so on. .

The invention is suitable for the manufacture of carbon nanotube composite transmission wires.

DRAWINGS

Figure 1 is a process flow diagram of the present invention;

2 is a schematic view of filling of carbon nanotubes;

Figure 3 is a schematic view of a rotary friction extrusion composite process _;

Figure number: 1 is the extrusion cavity; 2 is the composite product; 3 is the plasticized metal; 4 is the friction head; 5 is the raw material (CNT _S ); 6 is the aluminum plate.

detailed description The carbon nanotube powder 5 is filled in a uniformly drilled hole in the electrical aluminum block 6, and the two aluminum blocks 6 to which the multi-walled carbon nanotube powder 5 has been added are laminated in a blind hole method in an opposite manner, so that The wall carbon nanotube powder 5 can be wrapped therein, and then the high-speed rotating friction head 4 is inserted into the aluminum block to which the multi-walled carbon nanotube powder 5 has been added, the rotational speed of the friction head is 480 r/min, and the extrusion bar extrusion speed 24mm/min, the carbon nanotube/aluminum matrix composite material 2 is obtained, and the carbon nanotube/aluminum matrix composite material 2 is continuously rolled into a continuous rolling mill, the composite material is subjected to a rolling temperature of 500 ° C, and the rolling temperature is 150: After continuous rolling, the wire is drawn on the continuous and high-speed aluminum alloy wire drawing machine, and the pulling speed is 20m/s. After 13 times of pulling, the required carbon nanotube/aluminum composite round wire is drawn, and finally, The stranding machine is twisted, and a single-strand carbon nanotube composite transmission wire is obtained through a back-twisting and stress-relieving device. The results show that the average tensile strength of the prepared carbon nanotube composite transmission wire can reach 255MPa, and the average conductivity is 50.3% IACS (single wire diameter 4.63mm), compared with the measured ordinary electrical aluminum wire (average tensile strength 215MPa, conductive The rate averaged 49.8% IACS) has a certain increase.

Example 2 .

As shown in FIG. 2 and FIG. 3, the embodiment of the present invention is implemented by filling a multi-wall carbon nanotube powder 5 having a total mass of 5% into a uniformly drilled hole in the electrical aluminum block 6, and Two aluminum blocks 6 to which the multi-walled carbon nanotube powder 5 has been added are laminated in a blind hole method to the opposite manner, so that the multi-walled carbon nanotube powder 5 can be wrapped therein, and then the high-speed rotating friction head 4 is inserted into the In the aluminum block of the multi-walled carbon nanotube powder 5, the rotational speed of the friction head is 600 r/min, and the extrusion speed of the extruded rod is 30 mm/min, and the carbon nanotube/aluminum composite material 2 is obtained, and the carbon nanotube/aluminum is obtained. The base composite material 2 is continuously rolled into a continuous rolling mill, and the composite material has a rolling temperature of 55 (TC, the rolling temperature is 200 ° C: after continuous rolling, the wire is drawn on a continuous and high-speed aluminum alloy wire drawing machine, and the pulling speed is 25 m. /s, After 13 passes of the wire, the required carbon nanotube/aluminum composite round wire is drawn, and finally, it is twisted on a twisted machine, and a single-stranded carbon nanotube is obtained through a back-twisting and stress-relieving device. Composite transmission wire. The results show that the prepared carbon nanotube composite Electricity The average tensile strength of the wire can reach 321 MPa, the average conductivity is 51.2% IACS, and the measured tensile strength of ordinary electrical aluminum wire is 215 MPa on average, and the average conductivity is 49.8 °/. IACS (single wire diameter 4.63mm).

Example 3

As shown in FIG. 2 and FIG. 3, the embodiment of the present invention realizes that the multi-wall carbon nanotube powder 5, which accounts for 7% of the total mass, is filled in the small hole drilled in the electrical aluminum block 6, and Two aluminum blocks 6 to which the multi-walled carbon nanotube powder 5 has been added are laminated together in a blind hole method in the opposite manner, so that the multi-walled carbon nanotube powder 5 can be wrapped therein, and then the high-speed rotating friction head 4 is inserted. In the aluminum block in which the multi-walled carbon nanotube powder is added, the rotational speed of the friction head 4 is 720 r/min, and the extrusion speed of the extruded rod is 36 mm/min, and the carbon nanotube/aluminum-based composite material 2 is obtained, and the carbon nanotube/aluminum is obtained. The base composite material 2 is continuously rolled into a continuous rolling mill, the composite material has a rolling temperature of 600 Ό, and the rolling temperature is 350 ° C. After continuous rolling, the wire is drawn on a continuous and high-speed aluminum alloy wire drawing machine, and the pulling speed is 30 m/s: After 13 passes of the wire, the required carbon nanotube/aluminum matrix composite round wire is drawn, and finally, it is twisted on the stranding machine, and the single-strand carbon nanotube composite power transmission is obtained through the anti-twisting and stress-relieving device. wire. The results show that the average tensile strength of the prepared carbon nanotube composite transmission wire can reach 346 MPa, the average conductivity is 51.5% IACS, and the average tensile strength of the measured ordinary electrical aluminum wire is 215 MPa, and the average conductivity is 49.8% IACS (single wire diameter). 4.63mm) o This embodiment is a preferred embodiment. The obtained carbon nanotube/aluminum matrix composite material has the best tensile strength and electrical conductivity of the carbon nanotube composite transmission wire.

Claims

WO 2012/055155 , , , PCT/CN2011/001592 Claims

A method for manufacturing a carbon nanotube composite transmission wire, characterized in that a multi-wall carbon nanotube powder having a total mass of 1% to 7% is filled in a small hole drilled in an electric aluminum block, and two The aluminum blocks to which the multi-walled carbon nanotube powder has been added are laminated in the opposite manner in a blind hole method, so that the multi-walled carbon nanotube powder can be wrapped therein, and then formed by a friction extrusion process, that is, a high speed is formed in the middle. Rotating friction head, metal flow passage with small gap around the friction head, inserting the high-speed rotating friction head into the aluminum block to which the multi-walled carbon nanotube powder has been added, and adding multi-wall carbon nano-particles under the extrusion of the extruded rod The aluminum block of the tube powder is extruded toward the friction head and is broken through the metal flow passage, the rotation speed of the friction head is 480-720r/min, and the extrusion speed of the extrusion rod is 24-36 mm/min, and the obtained carbon nanotube/aluminum composite The material is continuously rolled into a continuous rolling mill, the composite material is rolled and rolled at a temperature of 500 ° C to 600 ° C, and the rolling temperature is 150 ° C to 350 ° C. After continuous rolling, the wire is drawn on a continuous and high-speed aluminum alloy wire drawing machine. Pull speed is 20-30m/s, after 13 passes of the wire, pull the required carbon nanotube/aluminum matrix composite round wire, and finally, twist it on the stranding machine, and obtain the single strand through the anti-twisting and stress-relieving device. Carbon nanotube composite transmission wire.