A rare earth aluminum alloy high-strength, high-conductivity and high-stability cable and its preparation method

Abstract

The present invention discloses a rare earth aluminum alloy high-strength, high-conductivity and high-stability cable and a preparation method thereof, belonging to the technical field of aluminum alloy cables. The rare earth aluminum alloy high-strength, high-conductivity and high-stability cable comprises aluminum alloy single wires, and the aluminum alloy single wires comprise the following components in mass percentages: rare earth 2.0% - 4.1%, rhenium 1.0% - 1.2%, copper 0.8% - 1.5%, yttrium 0.5% - 0.8%, cobalt 0.5% - 1.0%, nickel 0.2% - 0.5%, silicon carbide 0.05% - 0.3%, aluminum chloride 0.1% - 0.8%, the total content of impurity elements ≤ 0.1%, and the balance is aluminum. The present invention also discloses a preparation method of the rare earth aluminum alloy high-strength, high-conductivity and high-stability cable. By using the rare earth aluminum alloy high-strength, high-conductivity and high-stability cable and the preparation method thereof described in the present invention, the problems of low tensile strength, low conductivity and poor creep resistance of the existing aluminum alloy cables can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of aluminum alloy cables, and particularly to a rare earth aluminum alloy high-strength, high-conductivity, and high-stability cable and a preparation method thereof. Background Art

[0002] With the continuous development of society, the application scope and occasions of cables are increasing, and the requirements for cables are getting higher and higher. Especially for projects such as schools, hospitals, and real estate, the fire protection requirements are more stringent, and higher requirements are put forward for aspects such as high temperature resistance, high strength, and high conductivity of cables. Domestic cables generally use copper as the conductor, and the price of copper is relatively high, so the price of copper cables is relatively high. Aluminum alloy cables have the advantages of light weight and low price, so aluminum alloy cables have been developed. However, the electrical conductivity, heat resistance, and tensile strength of aluminum alloys are relatively low, and wire breakage problems are likely to occur during production and use, increasing the production cost of aluminum alloy cables and affecting the service life of aluminum alloy cables.

[0003] The existing patent CN202010720663.6 discloses a rare earth high-iron aluminum alloy cable, belonging to the technical field of aluminum alloy materials for power cables. The single wire of the rare earth high-iron aluminum alloy cable comprises the following components in mass percentage: iron 1.0 - 1.5%, silicon 0.03 - 0.08%, copper 0.02 - 0.08%, manganese 0.02 - 0.08%, magnesium 0.01 - 0.05%, titanium 0.01 - 0.08%, zirconium 0.01 - 0.08%, chromium 0.05 - 0.1%, strontium 0.01 - 0.05%, rare earth 0.8 - 1.5%, the total impurity content ≤ 0.1%, and the balance is aluminum. The elongation rate of the prepared rare earth high-iron aluminum alloy single wire > 35%, the tensile strength > 120 MPa, the number of 90° bending times is more than 38 times, the DC resistivity at 20°C ≤ 0.029, the conductivity ≥ 62.0% IACS, the bending radius is 7D, the rebound performance is reduced by 40% compared with copper cables, the anti-creep performance is increased by 300% compared with aluminum core cables, and the service life is not less than 40 years. However, the tensile strength, electrical conductivity, and anti-creep performance of the aluminum alloy cable single wire in the above patent are relatively low, which affects the stability and service life of cable use. Summary of the Invention

[0004] The purpose of the present invention is to provide a rare earth aluminum alloy high-strength, high-conductivity, and high-stability cable and a preparation method thereof, so as to solve the problems of low tensile strength, low electrical conductivity, and poor anti-creep performance of existing aluminum alloy cables.

[0005] To achieve the above-mentioned purpose, the present invention provides a rare earth aluminum alloy high-strength, high-conductivity and high-stability cable, comprising an aluminum alloy monofilament, wherein the aluminum alloy monofilament comprises the following components in mass percentage: rare earth 2.0%-4.1%, rhenium 1.0%-1.2%, copper 0.8%-1.5%, yttrium 0.5%-0.8%, cobalt 0.5%-1.0%, nickel 0.2%-0.5%, silicon carbide 0.05%-0.3%, aluminum chloride 0.1%-0.8%, the total content of impurity elements ≤0.1%, and the balance is aluminum.

[0006] Preferably, the rare earth element is a mixture of cerium, holmium, dysprosium and europium, wherein the mass percentage of cerium is 0.8%-1.5%, the mass percentage of holmium is 0.3%-1.0%, the mass percentage of dysprosium is 0.2%-0.8%, and the mass percentage of europium is 0.2%-0.8%.

[0007] Preferably, it includes an aluminum alloy conductor, which is made of twisted aluminum alloy monofilaments, an insulating layer is arranged on the outside of the aluminum alloy conductor, a plurality of aluminum alloy conductors are wrapped with glass fiber tapes on the outside, a filling layer is arranged between the glass fiber tapes and the insulating layer, an inner sheath layer is arranged on the outside of the glass fiber tapes, an outer sheath layer is arranged on the outside of the inner sheath layer, and an armor layer is arranged between the inner sheath layer and the outer sheath layer.

[0008] Preferably, the insulating layer is a cross-linked polyethylene layer, the armor layer is a galvanized steel strip layer, and the outer sheath layer is a cross-linked polyethylene layer.

[0009] The method for preparing the above-mentioned rare earth aluminum alloy high-strength, high-conductivity and high-stability cable comprises the following steps:

[0010] S1. Prepare materials: weigh and prepare the raw materials according to the set chemical composition;

[0011] S2, melting the aluminum ingot, placing the aluminum ingot into a melting furnace for melting, and keeping the temperature after melting to obtain aluminum liquid;

[0012] S3, grinding, putting silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for grinding and mixing to obtain a mixed powder; using an electromagnetic induction furnace to melt the mixed powder, using argon gas for protection during the melting process, and cooling after the melting is completed to obtain an aluminum-based composite material;

[0013] S4, adding the raw materials and the aluminum-based composite material into aluminum liquid, adding a grain refiner into the aluminum liquid, adding oxidized red sand powder into the aluminum liquid for smelting, refining and degassing, melting evenly and then keeping warm to obtain rare earth aluminum alloy liquid;

[0014] S5, casting, casting the rare earth aluminum alloy liquid into rare earth aluminum alloy bars;

[0015] S6. Rolling: Roll the rare earth aluminum alloy bar through a rolling mill to form a rare earth aluminum alloy rod with a diameter of Φ9.0 mm.

[0016] S7. Drawing: Use a 13-die wire drawing machine to draw the rare earth aluminum alloy rod into an oval-shaped rare earth aluminum alloy single wire, and twist the rare earth aluminum alloy single wires into a rare earth aluminum alloy conductor on a frame stranding machine using a special-shaped stranding die.

[0017] S8. Annealing: Place the rare earth aluminum alloy conductor in an annealing furnace for annealing.

[0018] S9. Insulation: After cooling, extrude an insulating layer of cross-linked polyethylene material outside the rare earth aluminum alloy conductor.

[0019] S10. Cabling and Sheathing: Place 3 - 4 insulated wire cores on a cabling machine for filling. After filling, use a fiberglass tape to wrap the cable and then extrude an inner sheath layer. After extruding the inner sheath layer, use galvanized steel tape for armoring, and then extrude an outer sheath layer with polyethylene material to form a cable.

[0020] Preferably, in S2, the purity of the aluminum ingot is not less than 99.8%, and the melting temperature is 750°C - 800°C.

[0021] Preferably, in S3, the addition amount of nano-graphene is 0.02% - 0.8%, the crushing time is 30 minutes, and the melting temperature of the mixed powder is 750°C - 800°C.

[0022] Preferably, in S4, the grain refiner is an Al-5Ti-B grain refiner, and the mass percentage of the grain refiner is 0.5% - 1%.

[0023] Preferably, in S8, the annealing temperature is 300°C ± 10°C, and the annealing time is 6 hours - 9 hours.

[0024] The elongation rate of the rare earth aluminum alloy single wire prepared by the above method for preparing a rare earth aluminum alloy high-strength, high-conductivity, and high-stability cable is ≥30%, the tensile strength is 180 N / mm 2 -240 N / mm 2 , the number of 90° bends is more than 30 times, the DC resistivity at 20°C is ≤0.0270 Ω / m, the conductivity is 64% - 65%, the bending radius is 7D - 10D, the rebound performance is reduced by 40% compared with a copper cable, the anti-creep performance is increased by 380% compared with an aluminum core cable, and the service life is not less than 45 years.

[0025] The advantages and positive effects of the rare earth aluminum alloy high-strength, high-conductivity, and high-stability cable and its preparation method of the present invention are:

[0026] 1. In the present invention, cerium, holmium, dysprosium, and europium rare earth elements are added to aluminum alloy. The rare earth elements modify the aluminum alloy, which can effectively refine the grains of the aluminum alloy and improve the strength and toughness of the aluminum alloy. Cerium element is mainly used to refine the grains of the aluminum alloy and purify the alloy. Holmium, dysprosium, and europium elements can enhance the thermal stability of the aluminum alloy and improve its high-temperature performance.

[0027] 2. Silicon carbide is added to the aluminum alloy in the present invention. As a hard particle, silicon carbide can not only improve the hardness and wear resistance of the aluminum alloy and increase its strength, but also the good thermal conductivity of silicon carbide can improve the thermal conductivity of the aluminum alloy and enhance its high-temperature resistance; and it can act as a heterogeneous nucleation point for the aluminum alloy to promote the crystallization of the aluminum alloy, achieving the effect of refining the grains, and silicon carbide can also improve the oxidation resistance or corrosion resistance of the aluminum alloy.

[0028] 3. The good conductivity of nano-graphene in the present invention can increase the electrical conductivity of the aluminum alloy and enhance its tensile strength and toughness.

[0029] 4. Rhenium, yttrium, and cobalt metal elements are added to the aluminum alloy in the present invention. Rhenium element increases the high-temperature strength and creep resistance of the aluminum alloy and improves the thermal stability of the aluminum alloy cable. Yttrium element can refine the grains of the aluminum alloy and improve its strength, toughness, and heat resistance. Cobalt element improves the strength and heat resistance of the aluminum alloy through solid solution strengthening and precipitation phase strengthening.

[0030] 5. In the present invention, ball milling is used to mix silicon carbide, nano-graphene with aluminum, which is beneficial to the uniform dispersion of silicon carbide and nano-graphene in the aluminum alloy and improves the uniformity of their dispersion.

[0031] The technical solution of the present invention will be further described in detail below through the drawings and embodiments. Description of the Drawings

[0032] Figure 1 It is a schematic cross-sectional structure diagram of the cable according to the embodiment of the present invention;

[0033] Figure 2 It is a flow chart according to the embodiment of the present invention.

[0034] Reference Signs

[0035] 1. Rare earth aluminum alloy conductor; 2. Insulation layer; 3. Filling layer; 4. Glass fiber tape; 5. Inner sheath layer; 6. Armor layer; 7. Outer sheath layer. Detailed Embodiments

[0036] The technical solution of the present invention will be further described below through the drawings and embodiments.

[0037] Unless otherwise defined, the technical terms or scientific terms used in the present invention shall have the ordinary meanings as understood by those of ordinary skill in the art to which the present invention pertains. The "first", "second" and similar terms used in the present invention do not denote any order, quantity or importance, but are only used to distinguish different components. Words such as "comprising" or "including" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to represent relative position relationships, and when the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0038] Figure 1 Schematic diagram of the cable cross-sectional structure according to an embodiment of the present invention. As Figure 1 shown, the rare earth aluminum alloy high-strength, high-conductivity and high-stability cable includes an aluminum alloy conductor, and the aluminum alloy conductor is made by stranding aluminum alloy single wires. The aluminum alloy single wire is of an elliptical structure, and the elliptical aluminum alloy single wires enable the aluminum alloy single wires to be tightly combined together, increasing the number of aluminum alloy single wires per unit area. An insulating layer is provided outside the aluminum alloy conductor, and the insulating layer is a cross-linked polyethylene layer, having good insulating effect. A plurality of aluminum alloy conductors are wrapped with a glass fiber tape, and the aluminum alloy conductors are wrapped and wound together by the glass fiber tape. In this embodiment, four aluminum alloy conductors are provided. A filling layer is provided between the glass fiber tape and the insulating layer, and the filling layer is insulating rubber, improving the insulating effect of the cable. An inner sheath layer is provided outside the glass fiber tape, an outer sheath layer is provided outside the inner sheath layer, and an armor layer is provided between the inner sheath layer and the outer sheath layer. The armor layer is a galvanized steel tape layer, and the armor layer protects the interior of the cable. The inner sheath layer and the outer sheath layer are both cross-linked polyethylene layers, having good insulating effect.

[0039] The rare earth aluminum alloy high-strength, high-conductivity and high-stability cable includes aluminum alloy single wires, and the aluminum alloy single wires include the following components by mass percentage: rare earth 2.0%-4.1%, rhenium 1.0%-1.2%, copper 0.8%-1.5%, yttrium 0.5%-0.8%, cobalt 0.5%-1.0%, nickel 0.2%-0.5%, silicon carbide 0.05%-0.3%, aluminum chloride 0.1%-0.8%, the total content of impurity elements ≤ 0.1%, and the balance is aluminum.

[0040] The rare earth elements are a mixture of cerium, holmium, dysprosium and europium, the mass percentage of cerium is 0.8%-1.5%, the mass percentage of holmium is 0.3%-1.0%, the mass percentage of dysprosium is 0.2%-0.8%, and the mass percentage of europium is 0.2%-0.8%.

[0041] Figure 2 This is the flowchart of the embodiment of the present invention. As Figure 2 shown, the preparation method of a rare earth aluminum alloy high-strength, high-conductivity and high-stability cable includes the following steps:

[0042] S1. Prepare materials, weigh and reserve the raw materials according to the set chemical composition.

[0043] S2. Melt the aluminum ingots, put the aluminum ingots into a melting furnace for melting, and keep warm after melting to obtain aluminum liquid.

[0044] The purity of the aluminum ingots is not less than 99.8%, and the melting temperature is 750°C - 800°C.

[0045] S3. Grind, put silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for grinding and mixing to obtain a mixed powder; use an electromagnetic induction furnace to melt the mixed powder, protect it with argon during the melting process, and cool it after melting to obtain an aluminum matrix composite material.

[0046] The addition amount of nano-graphene is 0.02% - 0.8%, the grinding time is 30 minutes, the particle size after grinding is powdery, and the melting temperature of the mixed powder is 750°C - 800°C.

[0047] S4. Add the raw materials and the aluminum matrix composite material to the aluminum liquid, add a grain refiner to the aluminum liquid, add oxidized red sand powder to the aluminum liquid for melting, refining, and degassing, keep warm after uniform melting to obtain rare earth aluminum alloy liquid.

[0048] The grain refiner is an Al-5Ti-B grain refiner, and the mass percentage of the grain refiner is 0.5% - 1%.

[0049] S5. Cast, cast the rare earth aluminum alloy liquid into rare earth aluminum alloy bars.

[0050] S6. Roll, roll the rare earth aluminum alloy bars through a rolling mill to roll them into rare earth aluminum alloy rods with a diameter of Φ9.0mm.

[0051] S7. Draw, use a 13-die wire drawing machine to draw the rare earth aluminum alloy rods into oval rare earth aluminum alloy single wires, and twist the rare earth aluminum alloy single wires into rare earth aluminum alloy conductors on a frame stranding machine using special-shaped stranding dies.

[0052] S8. Anneal, put the rare earth aluminum alloy conductors into an annealing furnace for annealing.

[0053] The annealing temperature is 300°C ± 10°C, and the annealing time is 6 hours - 9 hours.

[0054] S9. Insulation: After cooling, an insulating layer is extruded around the rare earth aluminum alloy conductor using cross-linked polyethylene material.

[0055] S10. Stranding and sheathing: Three to four insulated wire cores are placed on a stranding machine for filling. After filling, they are stranded and wrapped with fiberglass tape, and then an inner sheath layer is extruded. After extruding the inner sheath layer, galvanized steel tape armor is used, and then an outer sheath layer is extruded using polyethylene material to form a cable.

[0056] Example 1

[0057] A high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable includes aluminum alloy single wires. The aluminum alloy single wires include the following components by mass percentage: rare earth 2.2%, rhenium 1.0%, copper 1.4%, yttrium 0.7%, cobalt 0.6%, nickel 0.5%, silicon carbide 0.2%, aluminum chloride 0.3%, the total content of impurity elements ≤ 0.1%, and the balance is aluminum.

[0058] The mass percentage of cerium in the rare earth elements is 1.0%, the mass percentage of holmium is 0.4%, the mass percentage of dysprosium is 0.6%, and the mass percentage of europium is 0.2%.

[0059] A method for preparing a high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable includes the following steps:

[0060] S1. Stock preparation: Weigh and reserve the raw materials according to the set chemical composition.

[0061] S2. Melting aluminum ingots: Put the aluminum ingots into a melting furnace for melting, and keep them warm after melting to obtain aluminum liquid.

[0062] The purity of the aluminum ingots is not less than 99.8%, and the melting temperature is 750 °C.

[0063] S3. Grinding: Put silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for grinding and mixing to obtain a mixed powder. Use an electromagnetic induction furnace to melt the mixed powder, and use argon for protection during the melting process. After melting is completed, cool to obtain an aluminum matrix composite material.

[0064] The addition amount of nano-graphene is 0.6%, the grinding time is 30 minutes, the particle size after grinding is powdery, and the melting temperature of the mixed powder is 760 °C.

[0065] S4. Add the raw materials and the aluminum matrix composite material to the aluminum liquid, and add a grain refiner to the aluminum liquid. Add oxidized red sand powder to the aluminum liquid for melting, refining, and degassing. Keep warm after melting evenly to obtain a rare earth aluminum alloy liquid.

[0066] The grain refiner is an Al-5Ti-B grain refiner, and the mass percentage of the grain refiner is 0.5%.

[0067] S5. Casting: Cast the rare earth aluminum alloy liquid into rare earth aluminum alloy bars.

[0068] S6. Rolling: Roll the rare earth aluminum alloy bars through a rolling mill to form rare earth aluminum alloy rods with a diameter of Φ9.0 mm.

[0069] S7. Drawing: Use a 13-die wire drawing machine to draw the rare earth aluminum alloy rods into oval rare earth aluminum alloy single wires, and twist the rare earth aluminum alloy single wires into rare earth aluminum alloy conductors on a frame-type stranding machine using special-shaped stranding dies.

[0070] S8. Annealing: Put the rare earth aluminum alloy conductors into an annealing furnace for annealing.

[0071] The annealing temperature is 300°C ± 10°C, and the annealing time is 8 hours.

[0072] S9. Insulation: After cooling, extrude an insulating layer of cross-linked polyethylene material on the outside of the rare earth aluminum alloy conductors;

[0073] S10. Cabling and Sheathing: Place 4 insulated cores on a cabling machine for filling. After filling, use fiberglass tape to wrap the cable and then extrude an inner sheath layer. After extruding the inner sheath layer, use galvanized steel tape for armoring, and then extrude an outer sheath layer with polyethylene material to form a cable.

[0074] Example 2

[0075] A high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable, including aluminum alloy single wires. The aluminum alloy single wires include the following components by mass percentage: rare earth 3%, rhenium 1.0%, copper 1.2%, yttrium 0.6%, cobalt 0.8%, nickel 0.3%, silicon carbide 0.1%, aluminum chloride 0.6%, and the total content of impurity elements ≤ 0.1%, with the balance being aluminum.

[0076] The mass percentage of cerium in the rare earth elements is 1.0%, the mass percentage of holmium is 0.7%, the mass percentage of dysprosium is 0.7%, and the mass percentage of europium is 0.6%.

[0077] A preparation method for a high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable, including the following steps:

[0078] S1. Material preparation: Weigh and reserve the raw materials according to the set chemical composition.

[0079] S2. Melting aluminum ingots: Put the aluminum ingots into a melting furnace for melting, and keep them warm after melting to obtain aluminum liquid.

[0080] The purity of the aluminum ingots is not less than 99.8%, and the melting temperature is 780°C.

[0081] S3. Rolling: Put silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for crushing and mixing to obtain a mixed powder; use an electromagnetic induction furnace to melt the mixed powder, protect it with argon during the melting process, and cool it after melting to obtain an aluminum matrix composite material.

[0082] The addition amount of nano-graphene is 0.3%, the crushing time is 30 minutes, the particle size after crushing is powdery, and the melting temperature of the mixed powder is 780 °C.

[0083] S4. Add the raw materials and the aluminum matrix composite material into the molten aluminum, add a grain refiner to the molten aluminum, add oxidized red sand powder to the molten aluminum for melting, refining, and degassing, and keep it warm after uniform melting to obtain a rare earth aluminum alloy liquid.

[0084] The grain refiner is an Al-5Ti-B grain refiner, and the mass percentage of the grain refiner is 0.8%.

[0085] S5. Casting: Cast the rare earth aluminum alloy liquid to form a rare earth aluminum alloy bar.

[0086] S6. Rolling: Roll the rare earth aluminum alloy bar through a rolling mill to roll it into a rare earth aluminum alloy rod with a diameter of Φ9.0 mm.

[0087] S7. Drawing: Use a 13-die wire drawing machine to draw the rare earth aluminum alloy rod into an oval rare earth aluminum alloy single wire, and use a special-shaped stranding die on a frame stranding machine to strand the rare earth aluminum alloy single wires into a rare earth aluminum alloy conductor.

[0088] S8. Annealing: Put the rare earth aluminum alloy conductor into an annealing furnace for annealing.

[0089] The annealing temperature is 300 °C ± 10 °C, and the annealing time is 7 hours.

[0090] S9. Insulation: After cooling, extrude an insulating layer on the outside of the rare earth aluminum alloy conductor with cross-linked polyethylene material;

[0091] S10. Cabling and sheathing: Place 4 insulated cores on a cabling machine for filling, after filling, use a fiberglass tape to cable and wrap it, then extrude an inner sheath layer, after extruding the inner sheath layer, use galvanized steel tape for armoring, and then extrude an outer sheath layer with polyethylene material to form a cable.

[0092] Example 3

[0093] The high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable includes aluminum alloy single wires. The aluminum alloy single wires include the following components by mass percentage: rare earth 4.0%, rhenium 1.2%, copper 1.4%, yttrium 0.5%, cobalt 0.9%, nickel 0.2%, silicon carbide 0.2%, aluminum chloride 0.5%, the total content of impurity elements ≤ 0.1%, and the balance is aluminum.

[0094] The mass percentage of cerium in the rare earth elements is 1.5%, the mass percentage of holmium is 1.0%, the mass percentage of dysprosium is 0.7%, and the mass percentage of europium is 0.8%.

[0095] A preparation method of a rare earth aluminum alloy high-strength, high-conductivity and high-stability cable, comprising the following steps:

[0096] S1. Prepare materials, weigh and reserve the raw materials according to the set chemical composition.

[0097] S2. Melt the aluminum ingot, put the aluminum ingot into a melting furnace for melting, and keep it warm after melting to obtain aluminum liquid.

[0098] The purity of the aluminum ingot is not less than 99.8%, and the melting temperature is 800 °C.

[0099] S3. Roll and grind, put silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for grinding and mixing to obtain a mixed powder; use an electromagnetic induction furnace to melt the mixed powder, and use argon for protection during the melting process, and cool it after melting to obtain an aluminum matrix composite material.

[0100] The addition amount of nano-graphene is 0.1%, the grinding time is 30 minutes, the particle size after grinding is powdery, and the melting temperature of the mixed powder is 750 °C.

[0101] S4. Add the raw materials and the aluminum matrix composite material to the aluminum liquid, add a grain refiner to the aluminum liquid, add oxidized red sand powder to the aluminum liquid for melting, refining and degassing, and keep it warm after uniform melting to obtain rare earth aluminum alloy liquid.

[0102] The grain refiner is an Al-5Ti-B grain refiner, and the mass percentage of the grain refiner is 1%.

[0103] S5. Cast, cast the rare earth aluminum alloy liquid into a rare earth aluminum alloy bar.

[0104] S6. Roll, roll the rare earth aluminum alloy bar through a rolling mill to roll it into a rare earth aluminum alloy rod with a diameter of Φ9.0 mm.

[0105] S7. Draw, use a 13-die wire drawing machine to draw the rare earth aluminum alloy rod into an oval rare earth aluminum alloy single wire, and twist the rare earth aluminum alloy single wire into a rare earth aluminum alloy conductor on a frame-type stranding machine using a special-shaped stranding die.

[0106] S8. Anneal, put the rare earth aluminum alloy conductor into an annealing furnace for annealing.

[0107] The annealing temperature is 300 °C ± 10 °C, and the annealing time is 9 hours.

[0108] S9. Insulation: After cooling, an insulating layer is extruded around the rare earth aluminum alloy conductor using cross-linked polyethylene material.

[0109] S10. Stranding and sheathing: Four insulated wire cores are placed on a stranding machine for filling. After filling, they are stranded and wrapped with fiberglass tape, and then an inner sheath layer is extruded. After extruding the inner sheath layer, galvanized steel tape armor is used, and then an outer sheath layer is extruded using polyethylene material to form a cable.

[0110] The properties of the rare earth aluminum alloy single wires prepared in Examples 1 - 3 are tested, and the test results are shown in Table 1.

[0111] Table 1 Properties of the rare earth aluminum alloy single wires prepared in Examples 1 - 3

[0112] Item Example 1 Example 2 Example 3 Elongation rate (%) 31％ 34％ 33％ <![CDATA[Tensile strength (N / mm 2 )]]> 224 238 195 Number of 90° bends 35 40 38 DC resistivity at 20°C (Ω / m) 0.0268 0.0263 0.0270 Conductivity (%IACS) 64 65 64

[0113] The bending radius of the cables obtained in Examples 1 - 3 is 7D - 10D. The cable rebound performance is reduced by 40% compared to copper cables, and the anti-creep performance is increased by 380% compared to aluminum core cables. The service life is not less than 45 years, improving the service life and anti-creep performance of the cables, and having very good high-temperature stability.

[0114] Therefore, by using the high-strength, high-conductivity, and high-stability rare earth aluminum alloy cable and its preparation method described in the present invention, the problems of low tensile strength, low conductivity, and poor anti-creep performance of existing aluminum alloy cables can be solved.

[0115] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that they can still modify or equivalently replace the technical solutions of the present invention, and these modifications or equivalent replacements do not make the modified technical solutions deviate from the spirit and scope of the technical solutions of the present invention.

Claims

1. A rare earth aluminum alloy high-strength, high-conductivity, high-stability cable, characterized by: Including aluminum alloy monofilament, the aluminum alloy monofilament includes the following components by mass percentage: rare earth 2.0%-4.1%, rhenium 1.0%-1.2%, copper 0.8%-1.5%, yttrium 0.5%-0.8%, cobalt 0.5%-1.0%, nickel 0.2%-0.5%, silicon carbide 0.05%-0.3%, aluminum chloride 0.1%-0.8%, the total content of impurity elements ≤0.1%, and the balance is aluminum; A method for preparing a rare earth aluminum alloy high-strength, high-conductivity, high-stability cable, characterized in that it comprises the following steps: S1. Prepare materials: weigh and prepare the raw materials according to the set chemical composition; S2, melting the aluminum ingot, placing the aluminum ingot into a melting furnace for melting, and keeping the temperature after melting to obtain aluminum liquid; S3, grinding, putting silicon carbide, aluminum chloride, nano-graphene, and nano-aluminum powder into a ball mill for grinding and mixing to obtain a mixed powder; using an electromagnetic induction furnace to melt the mixed powder, using argon gas for protection during the melting process, and cooling after the melting is completed to obtain an aluminum-based composite material; S4, adding the raw materials and the aluminum-based composite material into aluminum liquid, adding a grain refiner into the aluminum liquid, adding oxidized red sand powder into the aluminum liquid for smelting, refining and degassing, melting evenly and then keeping warm to obtain rare earth aluminum alloy liquid; S5, casting, casting the rare earth aluminum alloy liquid into rare earth aluminum alloy bars; S6, rolling, rolling the rare earth aluminum alloy strip through a rolling mill to form a rare earth aluminum alloy rod with a diameter of Φ9.0 mm; S7, drawing, using a 13-die wire drawing machine to draw the rare earth aluminum alloy rod into an elliptical rare earth aluminum alloy monofilament, and twisting the rare earth aluminum alloy monofilament into a rare earth aluminum alloy conductor on a frame-type stranding machine using a special-shaped stranding die; S8, annealing, placing the rare earth aluminum alloy conductor into an annealing furnace for annealing; S9, insulation, after cooling, the outside of the rare earth aluminum alloy conductor is extruded with a cross-linked polyethylene material for insulation; S10, cabling and sheathing: 3-4 insulated cores are placed on a cabling machine for filling. After filling, they are wrapped with glass fiber tapes and then the inner sheath layer is extruded. After the inner sheath layer is extruded, galvanized steel tape is used for armoring, and then the outer sheath layer is extruded with polyethylene material to form a cable; In the S3, the addition amount of nanographene is 0.02%-0.8%, the grinding time is 30 minutes, and the melting temperature of the mixed powder is 750°C-800°C.

2. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 1, characterized in that: The rare earth is a mixture of cerium, holmium, dysprosium and europium, wherein the mass percentage of cerium is 0.8%-1.5%, the mass percentage of holmium is 0.3%-1.0%, the mass percentage of dysprosium is 0.2%-0.8%, and the mass percentage of europium is 0.2%-0.8%.

3. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 1, characterized in that: It includes an aluminum alloy conductor, which is made of twisted aluminum alloy monofilaments. An insulating layer is arranged on the outside of the aluminum alloy conductor. A plurality of aluminum alloy conductors are wrapped with glass fiber tapes on the outside. A filling layer is arranged between the glass fiber tapes and the insulating layer. An inner sheath layer is arranged on the outside of the glass fiber tapes. An outer sheath layer is arranged on the outside of the inner sheath layer. An armor layer is arranged between the inner sheath layer and the outer sheath layer.

4. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 3, characterized in that: The insulating layer is a cross-linked polyethylene layer, the armor layer is a galvanized steel belt layer, and the outer sheath layer is a cross-linked polyethylene layer.

5. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 1, characterized in that: In the S2, the purity of the aluminum ingot is not less than 99.8%, and the melting temperature is 750°C-800°C.

6. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 1, characterized in that: In the S4, the grain refiner is Al-5Ti-B refiner, and the mass percentage of the grain refiner is 0.5%-1%.

7. The rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to claim 1, characterized in that: In the S8, the annealing temperature is 300°C±10°C, and the annealing time is 6 hours to 9 hours.

8. A rare earth aluminum alloy high-strength, high-conductivity, high-stability cable according to any one of claims 1 to 7, characterized in that: The elongation of the prepared rare earth aluminum alloy monofilament is ≥30%, and the tensile strength is 180N / mm 2 -240N / mm 2 , 90° bending times more than 30 times, DC resistivity ≤0.0270Ω / m at 20℃, conductivity 64%-65%, bending radius 7D-10D, compared with copper cable, its rebound performance is reduced by 40%, compared with aluminum core cable, its creep resistance is increased by 380%, and its service life is not less than 45 years.

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