Preparation method of high specific rigidity composite wire

Abstract

The application relates to a preparation method of a high specific rigidity composite conductor wire, and relates to a preparation method of a composite conductor wire. The application aims at solving the problems of high density, low specific rigidity and low strength of the existing conductor wire. The beryllium / aluminum composite material rod after hot extrusion is subjected to jacketing treatment, and a multi-pass drawing method is adopted at high temperature to diffuse copper elements into the beryllium / aluminum composite material in the core to form metallurgical combination, realize high interface combination strength, obtain the low-density copper-jacketed beryllium / aluminum composite material composite conductor wire, and improve the rigidity of the conductor wire through the load bearing of the beryllium / aluminum composite material inner core. The beryllium / aluminum composite material is used as the inner core framework of the composite conductor wire to play the role of enhancement, and the density of the conductor wire can be greatly reduced. The specific rigidity of the high specific rigidity composite conductor wire prepared by the application is more than 27 GPa / (g / cm 3 ), and the conductivity is more than 4*10 7 S / m.

Description

Technical Field

[0001] The invention relates to a method for preparing a high-specific-rigidity composite conductor. Background Art

[0002] In aerospace and other specialized environments like space, electrical conductivity is a fundamental requirement for wires, but strict standards also exist for physical parameters such as strength, stiffness, and density. These demands stem from the extreme operating conditions of aerospace vehicles, and any material selection must comprehensively consider both performance and the application environment.

[0003] Among commonly used conductor materials, copper and aluminum are the two most widely used metals. Copper is known for its excellent electrical conductivity and can effectively conduct current. However, copper itself has a high density of 8.96g / cm 3 , which makes copper unable to meet the demand for lightweight materials. In addition, the elastic modulus of copper is 119GPa, and its specific stiffness is only 13.37GPa / (g / cm 3 ), which is far from meeting the demand for high stiffness, especially in environments subject to high loads or vibrations.

[0004] In comparison, aluminum has a lower density of only 2.7 g / cm 3 , which meets the requirements of lightweight materials. However, the elastic modulus of aluminum is only 71.7GPa, and its strength and stiffness cannot meet the needs of high-performance applications. In some precision equipment, gold and silver are widely used due to their excellent conductivity and stable chemical properties, but their densities are as high as 19.32g / cm 3 and 10.49 g / cm 3 , it is not suitable as a structural material and is expensive, which limits its feasibility in large-scale applications.

[0005] Therefore, there is an urgent need to develop composite conductor materials that meet both structural and functional requirements. Such composite conductors should combine the advantages of different materials, maintaining excellent conductivity while meeting aerospace requirements in terms of strength, stiffness, and density. Through innovative material design and manufacturing processes, future composite conductors will be able to perform exceptionally well in extreme environments, providing strong support for the development of aerospace technology. Summary of the Invention

[0006] The purpose of the present invention is to solve the problem of high density, low specific stiffness and low strength of existing wires and to provide a method for preparing a composite wire with high specific stiffness.

[0007] The preparation method of the high specific stiffness composite conductor of the present invention is carried out according to the following steps:

[0008] Step 1: Preparation of Be / Aluminum Composite Material

[0009] A beryllium / aluminum composite material is prepared by a self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 20% to 70%, and the aluminum matrix in the beryllium / aluminum composite material is pure aluminum or an aluminum alloy;

[0010] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die

[0011] First, preheat the beryllium / aluminum composite material to a temperature of 400-600°C, and then keep it at 400-600°C for 0.5-6 hours; preheat the hot extrusion die to a temperature 10-100°C lower than the preheating temperature of the beryllium / aluminum composite material, and then keep it at the temperature for 0.5-6 hours;

[0012] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0013] The preheated beryllium / aluminum composite material is loaded into a preheated hot extrusion die, and hot extruded using a press to obtain a beryllium / aluminum composite material rod;

[0014] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0015] The pure copper tube is heated to 200-600° C., and then a pure copper tube having the same inner diameter as the beryllium / aluminum composite material rod obtained in step 3 is sheathed on the outside of the rod, and the rod is naturally cooled to room temperature to obtain a copper-sheathed beryllium / aluminum composite material rod;

[0016] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0017] A copper-clad beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine, with a hot drawing temperature of 200-600°C, a deformation of 1%-10% in each pass, and a drawing rate of 10-200 mm / min. After each deformation pass, the copper-clad beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 0.5-2 mm.

[0018] The present invention has the following beneficial effects:

[0019] 1. The present invention sheaths the hot-extruded beryllium / aluminum composite rod and uses a multi-pass drawing method at high temperature to diffuse copper into the beryllium / aluminum composite material in the core, forming a metallurgical bond and achieving high interfacial bonding strength. This results in a low-density copper-sheathed beryllium / aluminum composite conductor. At the same time, the load-bearing capacity of the beryllium / aluminum composite core increases the rigidity of the conductor.

[0020] 2. The high-rigidity, low-density copper-sheathed beryllium / aluminum composite composite conductor prepared by the present invention can adjust the diameter of the beryllium / aluminum composite core and the thickness of the copper sheath according to actual needs to obtain composite conductors with different stiffness and density; the high-specific stiffness composite conductor prepared by the present invention has a specific stiffness of more than 27GPa / (g / cm 3 ), the conductivity exceeds 4×10 7 S / m.

[0021] 3. The present invention provides a method for efficiently and low-costly preparing a high-rigidity, low-density copper-clad beryllium / aluminum composite material composite conductor. The method has a simple process, is easy to operate, and is easy to realize industrial production and application.

[0022] 4. Beryllium / aluminum composite material has the excellent performance of high strength and low density, and is an excellent structural material. The density of beryllium / aluminum composite material is usually 2.1g / cm 3 The density of the composite wire is about 2.3×10-1, which is lower than that of pure aluminum. However, its strength is more than 5 times that of pure aluminum, which has extremely high specific strength and specific stiffness. The present invention uses the beryllium / aluminum composite material as the inner core skeleton of the composite wire to play a reinforcing role and significantly reduce the density of the wire. The electrical conductivity of beryllium is about 2.3×10 7 S / m, so the beryllium / aluminum composite material has higher electrical conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an energy spectrum scanning image of copper element diffusion into beryllium / aluminum composite material. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is not limited to the specific implementation methods listed below, but also includes any reasonable combination of the specific implementation methods.

[0025] Specific embodiment 1: The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0026] Step 1: Preparation of Be / Aluminum Composite Material

[0027] A beryllium / aluminum composite material is prepared by a self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 20% to 70%, and the aluminum matrix in the beryllium / aluminum composite material is pure aluminum or an aluminum alloy;

[0028] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die

[0029] First, preheat the beryllium / aluminum composite material to a temperature of 400-600°C, and then keep it at 400-600°C for 0.5-6 hours; preheat the hot extrusion die to a temperature 10-100°C lower than the preheating temperature of the beryllium / aluminum composite material, and then keep it at the temperature for 0.5-6 hours;

[0030] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0031] The preheated beryllium / aluminum composite material is loaded into a preheated hot extrusion die, and hot extruded using a press to obtain a beryllium / aluminum composite material rod;

[0032] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0033] The pure copper tube is heated to 200-600° C., and then a pure copper tube having the same inner diameter as the beryllium / aluminum composite material rod obtained in step 3 is sheathed on the outside of the rod, and the rod is naturally cooled to room temperature to obtain a copper-sheathed beryllium / aluminum composite material rod;

[0034] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0035] A copper-clad beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine, with a hot drawing temperature of 200-600°C, a deformation of 1%-10% in each pass, and a drawing rate of 10-200 mm / min. After each deformation pass, the copper-clad beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 0.5-2 mm.

[0036] This embodiment has the following beneficial effects:

[0037] 1. This embodiment performs a sheathing process on a hot-extruded beryllium / aluminum composite rod. A multi-pass drawing process is employed at high temperature to diffuse copper into the beryllium / aluminum composite material at the core, forming a metallurgical bond and achieving high interfacial bonding strength. This results in a low-density copper-sheathed beryllium / aluminum composite conductor. Furthermore, the load-bearing capacity of the beryllium / aluminum composite core increases the conductor's rigidity.

[0038] 2. The high-rigidity, low-density copper-clad beryllium / aluminum composite composite conductor prepared in this embodiment can adjust the diameter of the beryllium / aluminum composite core and the thickness of the copper sheath according to actual needs to obtain composite conductors with different stiffness and density; the high-specific stiffness composite conductor prepared in this embodiment has a specific stiffness of more than 27GPa / (g / cm 3 ), the conductivity exceeds 4×10 7 S / m.

[0039] 3. This embodiment provides a method for efficiently and at low cost to prepare a high-rigidity, low-density copper-clad beryllium / aluminum composite material composite conductor. The method has a simple process, is easy to operate, and is easy to realize industrial production and application.

[0040] 4、Beryllium / Aluminum composite material has excellent performance of high strength and low density, and is an excellent structural material. The density of Beryllium / Aluminum composite material is usually about 2.1 g / cm 3 3, which is lower than that of pure aluminum, but the strength can reach more than 5 times of that of pure aluminum, and has very high specific strength and specific stiffness. In the embodiment, the Beryllium / Aluminum composite material is used as the inner core framework of the composite wire, which plays a reinforcing role, and can greatly reduce the density of the wire. The electrical conductivity of Beryllium is about 2.3 x 10 7 S / m, so the Beryllium / Aluminum composite material has high electrical conductivity.

[0041] Specific implementation method two: the difference between the embodiment and the specific implementation method one is that the purity of the Beryllium powder in step one is greater than 99%, and the average particle size is 5-800 μm.

[0042] Specific implementation method three: the difference between the embodiment and the specific implementation method one or two is that the Beryllium powder in step one is one or a combination of several of irregular shape, spherical shape and Beryllium turning chips in any ratio.

[0043] Specific implementation method four: the difference between the embodiment and any one of the specific implementation methods one to three is that the aluminum alloy in step one is one or a combination of several of Al-Si alloy, Al-Cu alloy, Al-Mg alloy, Al-Si-Cu alloy, Al-Si-Mg alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg alloy, Al-Zn-Mg-Cu alloy, Al-Be alloy, Al-Li alloy and Al-Si-Cu-Mg alloy in any ratio.

[0044] Specific embodiment five: This embodiment is different from the specific embodiment four in that: the mass fraction of Si in the Al-Si alloy is 0.5% to 25%; the mass fraction of Cu in the Al-Cu alloy is 0.5% to 53%; the mass fraction of Mg in the Al-Mg alloy is 0.5% to 38%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5% to 25%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5% to 25%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Cu in the Al-Cu-Mg alloy is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in the Al-Zn-Cu alloy The mass fraction of Zn in Al-Zn-Mg alloy is 0.5% to 55%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in Al-Zn-Mg-Cu alloy is 0.5% to 55%, the mass fraction of Mg is 0.5% to 38%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Be in Al-Be alloy is 0.5% to 20%; the mass fraction of Li in Al-Li alloy is 0.5% to 35%; the mass fraction of Si in Al-Si-Cu-Mg alloy is 0.5% to 25%, the mass fraction of Cu is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%.

[0045] Specific embodiment 6: This embodiment differs from any one of specific embodiments 1 to 5 in that: the hot extrusion rate in step 3 is 30 mm / min to 120 mm / min.

[0046] Specific embodiment seven: This embodiment differs from any one of specific embodiments one to six in that the extrusion ratio of the hot extrusion in step three is (5-58):1.

[0047] Specific embodiment eight: This embodiment differs from any one of specific embodiments one to seven in that: the inner diameter of the pure copper tube in step four is 1 to 15 mm, and the outer diameter is 2 to 30 mm.

[0048] Specific embodiment nine: This embodiment differs from any one of specific embodiments one to eight in that: in step five, a drawing machine is used to perform multiple hot drawing on the beryllium / aluminum composite material rod, the hot drawing temperature is 540°C, the deformation amount of each pass is 3%, the drawing rate is 60 mm / min, and the beryllium / aluminum composite material is annealed after each deformation pass to obtain a copper-clad beryllium / aluminum composite material composite wire with a diameter of 2 mm; the annealing process is: keeping warm at 495°C for 5 hours.

[0049] Specific embodiment ten: This embodiment differs from any one of specific embodiments one to nine in that the annealing process in step five is: keeping the temperature at 200 to 600° C. for 1 to 72 hours.

[0050] The following examples are used to verify the effects of the present invention:

[0051] Example 1:

[0052] The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0053] Step 1: Preparation of Be / Aluminum Composite Material

[0054] Beryllium / aluminum composite materials were prepared by self-exhaust pressure infiltration method; the specific process is as follows:

[0055] ① Weigh beryllium powder and aluminum matrix at volume fractions of 60% and 40%, respectively. Place the beryllium powder into a steel mold and press it into a preform at a holding pressure of 50kN for 4 minutes. Then place the steel mold containing the beryllium powder preform into a preheating furnace and preheat it at 600°C for 2 hours. ② Melt the aluminum matrix at 880°C to obtain liquid aluminum, which is then poured into the preheated steel mold in step ①. ③ Move the pressing head downward at a pressure of 50MPa and a speed of 5mm / min to allow the liquid aluminum to penetrate into the gaps in the beryllium powder. Maintain the pressure at 25MPa for 3 minutes, and then cool it with circulating water to obtain a beryllium / aluminum composite material.

[0056] The aluminum matrix is ​​Al-1.5Mg-1.5Si alloy;

[0057] The beryllium powder has a purity of 99.5% and an average particle size of 50 μm; the beryllium powder is industrial beryllium powder with an irregular shape.

[0058] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die:

[0059] The beryllium / aluminum composite material was preheated to 540°C and then kept at 540°C for 2 hours; the hot extrusion die was preheated to 450°C and then kept at the same temperature for 3 hours;

[0060] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0061] The preheated beryllium / aluminum composite material was loaded into a preheated hot extrusion die and hot extruded using a press at a hot extrusion rate of 50 mm / min and an extrusion ratio of 49:1 to obtain a beryllium / aluminum composite material rod with a diameter of 5 mm.

[0062] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0063] Heat a pure copper tube with an inner diameter of 5 mm and an outer diameter of 7 mm to 300° C., then sleeve a pure copper tube with an inner diameter identical to that of the beryllium / aluminum composite rod obtained in step 3 over the rod, and naturally cool to room temperature to obtain a copper-clad beryllium / aluminum composite rod;

[0064] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0065] A beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine. The hot drawing temperature is 540°C, the deformation amount of each pass is 3%, and the drawing rate is 60 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 2 mm. The annealing process is: keeping the temperature at 495°C for 5 hours.

[0066] The density of the composite wire prepared in the embodiment is 5.49 g / cm 3 Compared with pure Cu wire, the density is reduced by 38.5%. The specific stiffness of the composite wire prepared in the embodiment is 39.4 GPa / (g / cm 3 ), the conductivity is 4.4×10 7 S / m. Figure 1 This is a scan of the energy spectrum of the copper element diffusing into the beryllium / aluminum composite material in this example. This indicates that the copper element has entered the inner core of the beryllium / aluminum composite material during the hot drawing process, forming a metallurgical bond between the copper sheath and the inner core.

[0067] Example 2:

[0068] The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0069] Step 1: Preparation of Be / Aluminum Composite Material

[0070] Beryllium / aluminum composite materials were prepared by self-exhaust pressure infiltration method; the specific process is as follows:

[0071] ① Weigh beryllium powder and aluminum matrix at volume fractions of 45% and 55%, respectively. Place the beryllium powder into a steel mold and press it into a preform at a holding pressure of 70kN for 10 minutes. The steel mold containing the beryllium powder preform is then placed in a preheating furnace and preheated at 620°C for 2 hours. ② Melt the aluminum matrix at 860°C to obtain liquid aluminum, which is then poured into the preheated steel mold in step ①. ③ Move the pressing head downward at a pressure of 30MPa and a speed of 6mm / min, allowing the liquid aluminum to infiltrate the gaps in the beryllium powder. Maintain the pressure at 30MPa for 5 minutes, and then cool it with circulating water to obtain a beryllium / aluminum composite material.

[0072] The aluminum matrix is ​​Al-1.2Mg alloy;

[0073] The beryllium powder has a purity of 99% and an average particle size of 80 μm; the beryllium powder is industrial beryllium powder with an irregular shape.

[0074] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die:

[0075] The beryllium / aluminum composite material is first preheated to a temperature of 530°C and then kept at 530°C for 2 hours; the hot extrusion die is preheated to a temperature of 440°C and then kept at the same temperature for 3 hours;

[0076] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0077] The preheated beryllium / aluminum composite material was loaded into a preheated hot extrusion die and hot extruded using a press at a hot extrusion rate of 80 mm / min and an extrusion ratio of 36:1 to obtain a beryllium / aluminum composite material rod with a diameter of 4 mm.

[0078] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0079] Heat a pure copper tube with an inner diameter of 4 mm and an outer diameter of 6 mm to 200° C., then sleeve a pure copper tube with an inner diameter identical to that of the beryllium / aluminum composite rod obtained in step 3 over the rod, and naturally cool to room temperature to obtain a copper-clad beryllium / aluminum composite rod;

[0080] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0081] A beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine. The hot drawing temperature is 520°C, the deformation amount of each pass is 4%, and the drawing rate is 40 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 1.8 mm. The annealing process is: keeping warm at 450°C for 8 hours.

[0082] The density of the composite wire prepared in the embodiment is 5.99 g / cm 3 Compared with pure Cu wire, the density is reduced by 32.9%. The specific stiffness of the composite wire prepared in the embodiment is 30.8GPa / (g / cm 3 ), the conductivity is 4.7×10 7 S / m.

[0083] Example 3:

[0084] The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0085] Step 1: Preparation of Be / Aluminum Composite Material

[0086] The beryllium / aluminum composite material is prepared by using the self-bleeding pressure infiltration method; the specific process is as follows:

[0087] ①Beryllium powder and aluminum matrix are weighed according to the volume fraction of 40% and 60%, the beryllium powder is pressed into a preform in a steel mold, the holding pressure is 90kN, and the holding time is 3min. Then the steel mold with the beryllium powder preform is placed in a preheating furnace and preheated at 530℃ for 2h; ②The aluminum matrix is melted at a temperature of 840℃ to obtain liquid aluminum, and then the liquid aluminum is poured into the steel mold after preheating in step ①; ③The liquid aluminum is infiltrated into the gap of the beryllium powder by moving the pressure head downward at a speed of 5mm / min and a pressure of 30MPa, and then the beryllium / aluminum composite material is obtained by cooling through circulating water under the pressure of 30MPa for 3min;

[0088] The aluminum matrix is Al-10Si alloy;

[0089] The purity of the beryllium powder is 99.6%, and the average particle size is 60μm; the beryllium powder is spherical beryllium powder.

[0090] Step two: preheating of the beryllium / aluminum composite material and the mold for hot extrusion:

[0091] First, the beryllium / aluminum composite material is preheated to a temperature of 480℃, and then the temperature is kept at 480℃ for 2h; the hot extrusion mold is preheated to a temperature of 400℃, and then the temperature is kept for 3h;

[0092] Step three: hot extrusion to prepare beryllium / aluminum composite material rod

[0093] The preheated beryllium / aluminum composite material is loaded into the preheated hot extrusion mold, and hot extrusion is carried out by using a press machine, the hot extrusion rate is 80mm / min, and the extrusion ratio is 40:1, to obtain a beryllium / aluminum composite material rod with a diameter of 5mm.

[0094] Step four: beryllium / aluminum composite material rod sleeving treatment

[0095] A pure copper tube with an inner diameter of 5mm and an outer diameter of 8mm is heated to 240℃, then a pure copper tube with the same diameter as the beryllium / aluminum composite material rod obtained in step three is sleeved on the outside of the rod, and naturally cooled to room temperature, to obtain a copper-sleeved beryllium / aluminum composite material rod;

[0096] Step five: hot drawing to prepare copper-sleeved beryllium / aluminum composite material composite wire

[0097] A beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine. The hot drawing temperature is 500°C, the deformation amount of each pass is 4%, and the drawing rate is 10 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 1.6 mm. The annealing process is: keeping warm at 345°C for 18 hours.

[0098] The density of the composite wire prepared in the embodiment is 6.36 g / cm 3 Compared with pure Cu wire, the density is reduced by 28.7%. The specific stiffness of the composite wire prepared in the embodiment is 27.4 GPa / (g / cm 3 ), the conductivity is 4.8×10 7 S / m.

[0099] Example 4:

[0100] The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0101] Step 1: Preparation of Be / Aluminum Composite Material

[0102] Beryllium / aluminum composite materials were prepared by self-exhaust pressure infiltration method; the specific process is as follows:

[0103] ① Weigh beryllium powder and aluminum matrix at volume fractions of 60% and 40%, respectively. Place the beryllium powder into a steel mold and press it into a preform at a holding pressure of 100kN for 3 minutes. Then place the steel mold containing the beryllium powder preform into a preheating furnace and preheat it at 600°C for 2 hours. ② Melt the aluminum matrix at 840°C to obtain liquid aluminum, which is then poured into the preheated steel mold in step ①. ③ Move the pressing head downward at a pressure of 40MPa and a speed of 5mm / min to allow the liquid aluminum to penetrate into the gaps in the beryllium powder. Maintain the pressure at 40MPa for 5 minutes, and then cool it with circulating water to obtain a beryllium / aluminum composite material.

[0104] The aluminum matrix is ​​Al-6.1Zn-2.9Mg alloy;

[0105] The beryllium powder has a purity of 99.7% and an average particle size of 100 μm; the beryllium powder has an irregular shape.

[0106] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die:

[0107] The beryllium / aluminum composite material is first preheated to a temperature of 500°C and then kept at 500°C for 2 hours; the hot extrusion die is preheated to a temperature of 450°C and then kept at the same temperature for 2 hours;

[0108] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0109] The preheated beryllium / aluminum composite material was loaded into a preheated hot extrusion die and hot extruded using a press at a hot extrusion rate of 80 mm / min and an extrusion ratio of 50:1 to obtain a beryllium / aluminum composite material rod with a diameter of 3 mm.

[0110] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0111] Heat a pure copper tube with an inner diameter of 3 mm and an outer diameter of 5 mm to 350° C., then sleeve a pure copper tube with an inner diameter identical to that of the beryllium / aluminum composite rod obtained in step 3 onto the outside of the rod, and naturally cool to room temperature to obtain a copper-clad beryllium / aluminum composite rod;

[0112] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0113] A beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine. The hot drawing temperature is 510°C, the deformation amount of each pass is 5%, and the drawing rate is 50 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 1.4 mm. The annealing process is: keeping warm at 435°C for 10 hours.

[0114] The density of the composite wire prepared in the embodiment is 6.50 g / cm 3 Compared with pure Cu wire, the density is reduced by 27.2%. The specific stiffness of the composite wire prepared in the embodiment is 27.2 GPa / (g / cm 3 ), the conductivity is 4.8×10 7 S / m.

[0115] Embodiment 5:

[0116] The preparation method of the high specific stiffness composite wire of this embodiment is carried out according to the following steps:

[0117] Step 1: Preparation of Be / Aluminum Composite Material

[0118] Beryllium / aluminum composite materials were prepared by self-exhaust pressure infiltration method; the specific process is as follows:

[0119] ① Weigh beryllium powder and aluminum matrix at volume fractions of 55% and 45%, respectively. Place the beryllium powder into a steel mold and press it into a preform at a holding pressure of 110kN for 3 minutes. Then place the steel mold containing the beryllium powder preform into a preheating furnace and preheat it at 550°C for 2 hours. ② Melt the aluminum matrix at 850°C to obtain liquid aluminum, which is then poured into the preheated steel mold in step ①. ③ Move the pressing head downward at a pressure of 40MPa and a speed of 5mm / min to allow the liquid aluminum to penetrate into the gaps in the beryllium powder. Maintain the pressure at 40MPa for 4 minutes, and then cool it with circulating water to obtain a beryllium / aluminum composite material.

[0120] The aluminum matrix is ​​Al-4.9Mg alloy;

[0121] The beryllium powder has a purity of 99.2% and an average particle size of 300 μm; the beryllium powder is beryllium turning chip recycled powder.

[0122] Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die:

[0123] The beryllium / aluminum composite material is first preheated to a temperature of 550°C and then kept at 550°C for 2 hours; the hot extrusion die is preheated to a temperature of 510°C and then kept at the same temperature for 3 hours;

[0124] Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion

[0125] The preheated beryllium / aluminum composite material was loaded into a preheated hot extrusion die and hot extruded using a press at a hot extrusion rate of 60 mm / min and an extrusion ratio of 25:1 to obtain a beryllium / aluminum composite material rod with a diameter of 6 mm.

[0126] Step 4: Sheathing of Beryllium / Aluminum Composite Rods

[0127] Heat a pure copper tube with an inner diameter of 6 mm and an outer diameter of 10 mm to 200° C., then sleeve a pure copper tube with an inner diameter identical to that of the beryllium / aluminum composite rod obtained in step 3 over the rod, and naturally cool to room temperature to obtain a copper-clad beryllium / aluminum composite rod;

[0128] Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing

[0129] A beryllium / aluminum composite material rod is subjected to multiple hot drawing passes using a drawing machine. The hot drawing temperature is 450°C, the deformation amount of each pass is 3%, and the drawing rate is 45 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 1 mm. The annealing process is: keeping warm at 320°C for 24 hours.

[0130] The density of the composite wire prepared in the embodiment is 6.51 g / cm 3 Compared with pure Cu wire, the density is reduced by 27.0%. The specific stiffness of the composite wire prepared in the embodiment is 27.0 GPa / (g / cm 3 ), the conductivity is 4.8×10 7 S / m.

Claims

1. A method for preparing a high specific stiffness composite conductor, characterized by: The preparation method of the high specific stiffness composite conductor is carried out according to the following steps: Step 1: Preparation of Be / Aluminum Composite Material A beryllium / aluminum composite material is prepared by a self-exhaust pressure infiltration method; the volume fraction of beryllium powder in the beryllium / aluminum composite material is 20% to 70%, and the aluminum matrix in the beryllium / aluminum composite material is pure aluminum or an aluminum alloy; Step 2: Preheating of Be / Aluminum Composite Material and Hot Extrusion Die First, preheat the beryllium / aluminum composite material to a temperature of 400-600°C, and then keep it at 400-600°C for 0.5-6 hours; preheat the hot extrusion die to a temperature 10-100°C lower than the preheating temperature of the beryllium / aluminum composite material, and then keep it at the temperature for 0.5-6 hours; Step 3: Preparation of Be / Aluminum Composite Rods by Hot Extrusion The preheated beryllium / aluminum composite material is loaded into a preheated hot extrusion die, and hot extruded using a press to obtain a beryllium / aluminum composite material rod; Step 4: Sheathing of Beryllium / Aluminum Composite Rods The pure copper tube is heated to 200-600° C., and then a pure copper tube having the same inner diameter as the beryllium / aluminum composite material rod obtained in step 3 is sheathed on the outside of the rod, and the rod is naturally cooled to room temperature to obtain a copper-sheathed beryllium / aluminum composite material rod; Step 5: Preparation of copper-clad beryllium / aluminum composite conductor by hot drawing The copper-clad beryllium / aluminum composite material rod is subjected to multiple hot drawing processes using a drawing machine. The hot drawing temperature is 200-600°C, the deformation amount of each process is 1%-10%, and the drawing rate is 10-200 mm / min. After each deformation process, the copper-clad beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 0.5-2 mm. The prepared high-specific stiffness composite wire has a specific stiffness exceeding 27 GPa / (g / cm 3 ).

2. The method for preparing a high specific stiffness composite conductor according to claim 1, characterized in that: The beryllium powder in step 1 has a purity greater than 99% and an average particle size of 5 to 800 μm.

3. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: The beryllium powder in step 1 is in the form of irregular shape, spherical shape, or beryllium turning chips, or a combination thereof in any ratio.

4. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: The aluminum alloy described in step 1 is one of Al-Si alloy, Al-Cu alloy, Al-Mg alloy, Al-Si-Cu alloy, Al-Si-Mg alloy, Al-Cu-Mg alloy, Al-Zn-Cu alloy, Al-Zn-Mg alloy, Al-Zn-Mg-Cu alloy, Al-Be alloy, Al-Li alloy and Al-Si-Cu-Mg alloy, or any combination of several of them.

5. The method for preparing a high specific stiffness composite conductor according to claim 4, characterized in that: The mass fraction of Si in the Al-Si alloy is 0.5% to 25%; the mass fraction of Cu in the Al-Cu alloy is 0.5% to 53%; the mass fraction of Mg in the Al-Mg alloy is 0.5% to 38%; the mass fraction of Si in the Al-Si-Cu alloy is 0.5% to 25%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Si in the Al-Si-Mg alloy is 0.5% to 25%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Cu in the Al-Cu-Mg alloy is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in the Al-Zn-Cu alloy is 0.5% to 55%, and the mass fraction of C is 0.5% to 10%. The mass fraction of u is 0.5% to 53%; the mass fraction of Zn in Al-Zn-Mg alloy is 0.5% to 55%, and the mass fraction of Mg is 0.5% to 38%; the mass fraction of Zn in Al-Zn-Mg-Cu alloy is 0.5% to 55%, the mass fraction of Mg is 0.5% to 38%, and the mass fraction of Cu is 0.5% to 53%; the mass fraction of Be in Al-Be alloy is 0.5% to 20%; the mass fraction of Li in Al-Li alloy is 0.5% to 35%; the mass fraction of Si in Al-Si-Cu-Mg alloy is 0.5% to 25%, the mass fraction of Cu is 0.5% to 53%, and the mass fraction of Mg is 0.5% to 38%.

6. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: The hot extrusion rate in step 3 is 30 mm / min to 120 mm / min.

7. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: The extrusion ratio of the hot extrusion in step 3 is (5-58):

1.

8. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: The inner diameter of the pure copper tube in step 4 is 1 to 15 mm, and the outer diameter is 2 to 30 mm.

9. The method for preparing a high specific stiffness composite conductor according to claim 1, wherein: Step 5: Using a drawing machine, the beryllium / aluminum composite material rod is subjected to multiple hot drawing passes. The hot drawing temperature is 540° C., the deformation amount of each pass is 3%, and the drawing rate is 60 mm / min. After each deformation pass, the beryllium / aluminum composite material is annealed to obtain a copper-clad beryllium / aluminum composite wire with a diameter of 2 mm. The annealing process is: keeping warm at 495° C. for 5 hours.

10. The method for preparing a high specific stiffness composite conductor according to claim 1, characterized in that: The annealing process in step 5 is: keeping the temperature at 200-600° C. for 1-72 hours.

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