High-conductivity corrosion-resistant aluminum-carbon-aluminum composite pipe and preparation method thereof

Abstract

The invention relates to the technical field of aluminum alloy composite pipes, in particular to a high-conductivity corrosion-resistant aluminum-carbon-aluminum composite pipe and a preparation method thereof.The aluminum-carbon-aluminum composite pipe comprises a base layer, a core layer and a coating layer, the base layer and the coating layer are made of aluminum alloy, the core layer is made of high-conductivity carbon fiber fabric, and the coating layer is made of high-conductivity carbon fiber fabric. The preparation method comprises the steps of S1, coating layer manufacturing, S2, basic structure assembling, S3, gradient preheating, S4, extrusion forming, S5, cold drawing and S6, annealing treatment. According to the method for compounding the aluminum alloy pipe with the high-conductivity carbon fibers, the conductivity and corrosion resistance of the aluminum alloy pipe are improved, the weight of the pipe can be reduced, and the aluminum alloy pipe has the better replacement effect and use universality.

Description

Technical Field

[0001] The invention relates to the technical field of aluminum alloy composite pipes, and in particular to a highly conductive, corrosion-resistant aluminum-carbon-aluminum composite pipe and a preparation method thereof. Background Art

[0002] As a material with good electrical conductivity and corrosion resistance, copper tubes are widely used in high-conductivity and corrosion-resistant scenes in the fields of electricity, vehicles, ships, and oceans. However, the density of copper is relatively high, reaching 8.92g / cm 3 , resulting in a larger mass of copper pipes, and relatively small reserves of copper ore, the cost of using copper pipes is high, which is obviously difficult to adapt to the growing needs of the industry. Therefore, aluminum alloy, with its advantages of light weight and low cost, has become an inevitable development trend in various industries to replace copper with aluminum. Under some special conditions of use in the ship field, it is necessary to ensure that the pipes have high conductivity to avoid potential corrosion of the pipes, but traditional aluminum alloy pipes cannot meet the requirements of high conductivity and corrosion resistance at the same time. Summary of the invention

[0003] In view of the above problems, the present invention provides a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe and a preparation method thereof to solve the problem in the prior art that copper pipes are high in cost and the conductivity and corrosion resistance of traditional aluminum alloy pipes cannot meet the requirements.

[0004] To achieve the above objectives, the present invention provides a highly conductive, corrosion-resistant aluminum-carbon-aluminum composite pipe, comprising a base layer, a core layer and a cladding layer, wherein the base layer and the cladding layer are made of aluminum alloy, and the core layer is made of highly conductive carbon fiber fabric.

[0005] A method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe, which is used to prepare the aluminum-carbon-aluminum composite pipe, and the preparation method comprises the following steps:

[0006] S1 Cladding layer production: Aluminum alloy solid bar is made into a cladding layer aluminum alloy tube by hot extrusion, and the cladding layer aluminum alloy tube is cut into sections, polished, and aluminum chips in the cladding layer aluminum alloy tube are blown away;

[0007] S2 Basic structure assembly: select a base aluminum alloy bar of the same length as the cladding aluminum alloy tube, wrap the core layer high conductive carbon fiber fabric around the base aluminum alloy bar, and then sleeve the cladding aluminum alloy tube on the outside of the core layer high conductive carbon fiber fabric to form an aluminum-carbon-aluminum assembly structure;

[0008] S3 gradient preheating: perform segmented gradient preheating on the head, middle and tail of the aluminum-carbon-aluminum assembly structure;

[0009] S4 extrusion molding: the preheated aluminum-carbon-aluminum assembly structure is extruded to form an aluminum-carbon-aluminum composite tube blank with full metallurgical bonding;

[0010] S5 cold drawing: cold drawing the aluminum-carbon-aluminum composite tube billet and controlling the deformation amount of the aluminum-carbon-aluminum composite tube billet;

[0011] S6 annealing treatment: annealing the aluminum-carbon-aluminum composite tube blank to make an aluminum-carbon-aluminum composite tube finished product.

[0012] Furthermore, in step S1, the thickness of the cladding layer aluminum alloy tube is 10% of the outer diameter, and the surface roughness of the cladding layer aluminum alloy tube Ra≤3.2 μm.

[0013] Furthermore, in step S2, the wrapping thickness of the core layer high conductive carbon fiber fabric is 1 to 3% of the outer diameter of the cladding layer aluminum alloy tube, the gap value between the cladding layer aluminum alloy tube and the core layer high conductive carbon fiber fabric is 1 to 3 mm, and the diameter of the base aluminum alloy rod is the inner diameter of the cladding layer aluminum alloy tube minus the difference between the thickness of the zinc layer high conductive carbon fiber fabric and the gap value.

[0014] Furthermore, in step S3, the temperature difference between the head and the middle, and between the middle and the tail of the aluminum-carbon-aluminum assembly structure is 20° C. and 50° C. respectively.

[0015] Furthermore, in step S4, the extrusion speed is 40-60 m / min, and the extrusion outlet temperature is ≤540°C.

[0016] Furthermore, in step S5, the deformation amount of each cold drawing process is less than 25%.

[0017] Furthermore, in step S6, the annealing temperature is 300-360° C., and the holding time is 1-2 hours.

[0018] Beneficial effects of the present invention:

[0019] The present invention improves the conductivity and corrosion resistance of the aluminum alloy pipe by a method of compounding highly conductive carbon fiber with the aluminum alloy pipe, and is beneficial to reducing the weight of the pipe. Good conductivity can effectively avoid the occurrence of potential corrosion, so that the composite pipe has a better replacement effect and wide application.

[0020] The present invention avoids slippage between metal and metal assemblies through the arrangement of carbon fiber interlayers, thereby ensuring stability; ensures consistency of grain structure at the head, middle and tail of the tube blank during the extrusion process by performing segmented gradient preheating on the aluminum-carbon-aluminum assembly structure; achieves a bonding force of more than 90 MPa through extrusion to avoid failure phenomena such as loose bonding between the base layer, the core layer and the cladding layer, and material separation during the cold drawing process; controls the deformation amount of each cold drawing pass to avoid failure phenomena such as breaking or faulting of the carbon fiber in the core layer due to excessive deformation, thereby ensuring the conductive effect. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work belong to the protection scope of the present invention.

[0022] In a specific embodiment of the present invention, a highly conductive, corrosion-resistant aluminum-carbon-aluminum composite pipe includes a base layer, a core layer and a cladding layer. The base layer and the cladding layer are made of aluminum alloy, and the core layer is made of highly conductive carbon fiber fabric.

[0023] A method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe is used to prepare the above-mentioned aluminum-carbon-aluminum composite pipe, and the preparation method comprises the following steps:

[0024] S1. Preparation of cladding layer: Aluminum alloy solid bar is made into cladding layer aluminum alloy tube by hot extrusion, the thickness of cladding layer aluminum alloy tube is 10% of the outer diameter, and the cladding layer aluminum alloy tube is cut into segments, each segment has a cutting length of 600-800 mm, the cladding layer aluminum alloy tube is polished, the surface roughness of the cladding layer aluminum alloy tube is controlled to be Ra≤3.2μm, and aluminum chips in the cladding layer aluminum alloy tube are purged and removed;

[0025] S2 basic structure assembly: select a base aluminum alloy bar of the same length as the cladding aluminum alloy tube, wrap the core layer high conductive carbon fiber fabric around the base aluminum alloy bar, the wrapping thickness of the core layer high conductive carbon fiber is 2% of the outer diameter of the cladding aluminum alloy tube, then sleeve the cladding aluminum alloy tube on the outside of the core layer high conductive carbon fiber fabric, and keep a 3mm gap between the cladding aluminum alloy tube and the core layer high conductive carbon fiber fabric to form an aluminum-carbon-aluminum assembly structure;

[0026] S3 gradient preheating: The head, middle and tail of the aluminum-carbon-aluminum assembly structure are preheated in sections. The preheating temperature of the head is the highest. The temperature difference between the head and the middle is 20°C, and the temperature difference between the middle and the tail is 50°C.

[0027] S4 extrusion molding: the preheated aluminum-carbon-aluminum assembly structure is extruded at an extrusion speed of 60m / min and an extrusion outlet temperature of 540°C to form an aluminum-carbon-aluminum composite tube blank with sufficient metallurgical bonding;

[0028] S5 cold drawing: cold drawing the aluminum-carbon-aluminum composite tube billet, and controlling the deformation of each cold drawing process of the aluminum-carbon-aluminum composite tube billet to be less than 25%;

[0029] S6 annealing treatment: the aluminum-carbon-aluminum composite tube billet is annealed at a temperature of 300 to 360°C for a holding time of 1 to 2 hours to finally produce an aluminum-carbon-aluminum composite tube product.

[0030] The composite pipe of the present invention and conventional aluminum pipes and copper pipes were tested for conductivity and corrosion resistance. The test results are shown in the following table:

[0031]

[0032] Comparing and analyzing the test data of conductivity, the conductivity of the composite pipe is significantly better than that of the aluminum pipe, and is equivalent to that of the copper pipe. Comparing and analyzing the experimental results of the circulating acidic seawater test SWAAT, the corrosion resistance of the composite pipe is significantly better than that of the aluminum pipe and close to that of the copper pipe.

[0033] In addition to the electrical conductivity and corrosion resistance, the quality of the pipes is compared and analyzed. Under the same volume conditions, the weight of the aluminum pipe is about 1 / 3 of that of the copper pipe, while the weight of the composite pipe is 10% lighter than that of the aluminum pipe, which meets the requirements of lightweight composite pipes.

[0034] As for the production cost of pipes, compared with the material cost of pipes of the same volume, the material cost of composite pipes is twice that of aluminum pipes, while the material cost of copper pipes is three times that of aluminum pipes; compared with the total cost of pipes of the same volume, the total cost of composite pipes is about twice that of aluminum pipes, while the total cost of composite pipes is more than 15% lower than that of copper pipes; in general, the cost of composite pipes is higher than that of aluminum pipes but lower than that of copper pipes;

[0035] In summary, the electrical conductivity and corrosion resistance of composite pipes are significantly stronger than those of aluminum pipes. Compared with copper pipes, the electrical conductivity and corrosion resistance of composite pipes are similar, while the quality and cost of composite pipes are much lower than those of copper pipes. Considering comprehensively from the perspectives of electrical conductivity, corrosion resistance, lightweight and production cost, composite pipes can be completely used as a substitute for copper pipes.

[0036] The above disclosure is only a preferred embodiment of the present invention, which certainly cannot be used to limit the scope of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A highly conductive, corrosion-resistant aluminum-carbon-aluminum composite pipe, characterized in that: It comprises a base layer, a core layer and a cladding layer, wherein the base layer and the cladding layer are made of aluminum alloy, and the core layer is made of highly conductive carbon fiber fabric.

2. A method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe, used for preparing the aluminum-carbon-aluminum composite pipe as claimed in claim 1, characterized in that: The preparation method comprises the following steps: S1 Cladding layer production: Aluminum alloy solid bar is made into a cladding layer aluminum alloy tube by hot extrusion, and the cladding layer aluminum alloy tube is cut into sections, polished, and aluminum chips in the cladding layer aluminum alloy tube are blown away; S2 Basic structure assembly: select a base aluminum alloy bar of the same length as the cladding aluminum alloy tube, wrap the core layer high conductive carbon fiber fabric around the base aluminum alloy bar, and then sleeve the cladding aluminum alloy tube on the outside of the core layer high conductive carbon fiber fabric to form an aluminum-carbon-aluminum assembly structure; S3 gradient preheating: perform segmented gradient preheating on the head, middle and tail of the aluminum-carbon-aluminum assembly structure; S4 extrusion molding: the preheated aluminum-carbon-aluminum assembly structure is extruded to form an aluminum-carbon-aluminum composite tube blank with full metallurgical bonding; S5 cold drawing: cold drawing the aluminum-carbon-aluminum composite tube billet and controlling the deformation amount of the aluminum-carbon-aluminum composite tube billet; S6 annealing treatment: annealing the aluminum-carbon-aluminum composite tube blank to make an aluminum-carbon-aluminum composite tube finished product.

3. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S1, the thickness of the cladding layer aluminum alloy tube is 10% of the outer diameter, and the surface roughness of the cladding layer aluminum alloy tube Ra≤3.2 μm.

4. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S2, the wrapping thickness of the core layer high conductive carbon fiber fabric is 1 to 3% of the outer diameter of the cladding layer aluminum alloy tube, the gap value between the cladding layer aluminum alloy tube and the core layer high conductive carbon fiber fabric is 1 to 3 mm, and the diameter of the base aluminum alloy rod is the inner diameter of the cladding layer aluminum alloy tube minus the difference between the thickness of the zinc layer high conductive carbon fiber fabric and the gap value.

5. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S3, the temperature difference between the head and the middle, and between the middle and the tail of the aluminum-carbon-aluminum assembly structure is 20° C. and 50° C. respectively.

6. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S4, the extrusion speed is 40-60 m / min, and the extrusion outlet temperature is ≤540°C.

7. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S5, the deformation amount of each cold drawing process is less than 25%.

8. The method for preparing a highly conductive and corrosion-resistant aluminum-carbon-aluminum composite pipe according to claim 2, characterized in that: In step S6, the annealing temperature is 300-360° C., and the holding time is 1-2 hours.

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