CN105703096A - Copper-aluminum transition terminal of Al-Fe-Mn-RE aluminum alloy cable and preparation method thereof - Google Patents

Abstract

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal belongs to the technical field of copper-aluminum transition terminal, including an aluminum alloy connecting tube connected to the cable conductor, a copper nose connected to the other end of the aluminum alloy connecting tube, and an aluminum alloy connecting tube. A copper-aluminum transition piece is arranged between the connecting pipe and the copper nose, and the copper-aluminum transition piece is an aluminum alloy with a columnar solid structure. The invention also provides a preparation method for preparing the copper-aluminum transition terminal of the Al-Fe-Mn-RE aluminum alloy cable. The preparation method is simple and easy to operate, and the prepared copper-aluminum transition terminal has excellent electrical, mechanical and creep resistance properties , In the case of constant temperature changes, it also has reliable connectivity, with excellent thermal stability and electrical conductivity, and the transition from aluminum alloy cable to connecting tube to copper nose is smooth and gentle.

Description

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal and preparation method thereof

technical field

The invention belongs to the technical field of copper-aluminum transition terminals, and relates to a copper-aluminum transition terminal for aluminum alloy cables, in particular to an Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal and a preparation method thereof. The copper-aluminum transition terminal of the invention has excellent electrical properties, mechanical properties and creep resistance, reliable quality and no potential safety hazard.

Background technique

With the rapid development of my country's economic construction, the demand for electricity in various industries continues to increase, and the market space for the wire and cable industry is huge. However, copper and aluminum conductors, which are the main components in the wire and cable product structure, have their own shortcomings that are difficult to overcome, so it is necessary to design and manufacture copper-aluminum transition terminals.

The existing copper-aluminum transition terminals are mainly composed of copper noses and ordinary aluminum connecting pipes. The copper noses are mainly made of electrical copper, and the connecting pipes are mostly made of ordinary aluminum materials, such as 1350 brand aluminum materials. The ordinary copper-aluminum transition terminals are used for aluminum Alloy cables have the following defects: 1. Ordinary aluminum materials are prone to creep under the effect of constant temperature changes for a long time, causing irreversible changes in their structural dimensions. 2. Cylindrical connecting tubes are used for special-shaped conductors of low-voltage power cables (such as fan-shaped, tile-shaped, and semi-circular). Since the shapes of the two are too different, even if plastic measures are taken during the joint, it is difficult to ensure that the conductor is rounded. , resulting in an uneven gap between the outer surface of the conductor and the inner wall of the connecting pipe, which brings hidden dangers to the long-term stable operation of the cable. 3. The safety of the cable is mainly limited by the stability of the terminal connection. At present, aluminum alloy cables mainly use copper-aluminum transition terminals, the copper nose is made of electrical copper, and the connecting pipe is pure aluminum instead of aluminum alloy. As a result, after the aluminum terminal and the aluminum alloy conductor are crimped, there are potential safety hazards in the use process. At the same time, the mechanical strength of the aluminum conductor is low, the welding performance is poor, and the contact resistance is large. The promotion and application in engineering projects is limited. 4. The existing copper-aluminum transition terminal is an integral structure of direct welding of aluminum connecting pipe and copper nose. Due to the difference in resistivity and current-carrying capacity between aluminum and copper, the direct transition from aluminum to copper will cause electrical phenomena. Copper-aluminum The joint surface is broken, which is easy to cause electric shock and other hazards. This existing copper-aluminum transition terminal transitions from aluminum alloy cable to aluminum and then transitions to copper. The transition method of mandatory and hard transfer has serious quality problems and potential safety hazards. 5. At present, the production process of copper and aluminum terminals in the market generally adopts the process of welding copper and aluminum rods first and then stamping them. When the copper rods are stamped into a plane close to 90°, the copper section at the weld seam will stretch toward the stamping direction Oblique deformation, and because aluminum is more ductile than copper, the aluminum on the edge of the weld is also stretched in the direction of the stamping, causing the entire weld to deform obliquely, resulting in variation of the molecular crystal structure around the aluminum section, cracks, and looseness Phenomena such as this affect the firmness of the entire welding surface (DTL type products are directly stamped on the weld, and the impact on the weld is more serious), and the firmness of the copper-aluminum welding surface is the most critical point of the entire connector. When using copper-aluminum connectors with weak welding, weak welding and affected molecular crystal structure of the welding surface, it is easy to cause fracture and galvanic corrosion of the copper-aluminum joint surface, resulting in power interruption, electric shock and fire accidents.

There are also connecting pipes and copper noses made of aluminum alloy. Although this design can improve the power output to a certain extent, this transition method still exists because the resistance of the joint surface increases, which is prone to short circuit and overheating. And the problem of section fracture, electrochemical reaction and bottleneck effect occur in the copper-aluminum transition zone. Therefore, for the further development of the aluminum alloy cable industry, it is urgent to study and solve the technical solution of the copper-aluminum transition terminal.

Contents of the invention

The present invention aims to solve the problem that the copper-aluminum transition terminal in the prior art has great quality problems and potential safety hazards in the connection of aluminum alloy cables due to its poor electrical, mechanical and creep resistance capabilities, and provides An Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal and a preparation method thereof are disclosed. The copper-aluminum transition terminal of the present invention has excellent electrical properties, mechanical properties, and creep resistance. It also has reliable connectivity under the condition of constant temperature changes, and has excellent thermal stability and electrical conductivity. It can be used from aluminum alloy cables to connections The transition from tube to copper nose is smooth and gentle.

The technical scheme that the present invention adopts for realizing its purpose is:

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting tube connected to the cable conductor, a copper nose connected to the other end of the aluminum alloy connecting tube, and a set between the aluminum alloy connecting tube and the copper nose A copper-aluminum transition piece, the copper-aluminum transition piece is an aluminum alloy with a columnar solid structure, and the copper-aluminum transition piece contains by weight percentage: Fe0.2-0.6%, Cu0.5-1.4%, Mg0.03-0.4 %, Mn0.05-0.5%, Sc0.01-0.03%, Sn0.001-0.003%, RE0.1-0.6%, V0.01-0.05%, Zr0.005-0.008%, Sr0.001-0.003% , Ni0.01-0.02%, Zn0.001-0.002%, and the balance is aluminum. The control of the chemical composition and ratio of the copper-aluminum transition piece improves the thermal expansion coefficient of the copper-aluminum transition area, improves the overload resistance, and realizes the smooth transition of the current from the aluminum alloy connection tube to the copper nose.

The copper-aluminum transition piece contains by weight percentage: Fe0.3-0.5%, Cu0.8-1.2%, Mg0.1-0.3%, Mn0.1-0.4%, Sc0.015-0.025%, Sn0.0015 -0.0025%, RE0.2-0.4%, V0.02-0.04%, Zr0.006-0.007%, Sr0.0015-0.0025%, Ni0.012-0.018%, Zn0.0013-0.0017%, the balance is aluminum .

The copper-aluminum transition piece contains by weight percentage: Fe0.4%, Cu1.0%, Mg0.2%, Mn0.2%, Sc0.02%, Sn0.002%, RE0.5%, V0.03 %, Zr0.006%, Sr0.002%, Ni0.015%, Zn0.0015%, and the balance is aluminum.

The diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe. This design is mainly due to the fact that the length of the copper-aluminum transition piece is shorter than the length of the aluminum alloy connecting pipe. The transition should ensure the stability of the transmission resistance and slowly reduce the resistance. Therefore, the inventor designed the diameter of the copper-aluminum transition piece to be smaller than the diameter of the aluminum alloy connecting pipe. Further preferably, the length of the copper-aluminum transition piece is the length of the aluminum alloy connection. 1/4-1/3 of the length of the pipe, and the diameter of the copper-aluminum transition piece is 1/3-1/2 of the diameter of the aluminum alloy connecting pipe.

The material composition of the aluminum alloy connection tube is the same as that of the connected cable conductor. This design makes the transition between the aluminum alloy connection tube and the cable conductor natural and stable, without causing current jumps or large fluctuations, and reduces the transmission resistance. It avoids the heating phenomenon caused by passing through a variety of media.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.3-1.7%, Cu0.01-0.4%, Mg0.01-0.2%, Mn0.01-0.08%, Sc0.02-0.06%, Sn0.002- 0.005%, RE0.1-0.6%, V0.02-0.08%, Zr0.003-0.005%, and the balance is aluminum. This aluminum alloy connecting tube can be applied to all aluminum alloy cables. This aluminum alloy connecting tube does not need to consider the chemical composition of the aluminum alloy cable. By controlling the ratio of each element of this aluminum alloy connecting tube, it can effectively avoid heating caused by different media. phenomenon, it can also achieve a natural and smooth transition between the cable conductor and the aluminum alloy connecting tube, without causing current jumps and large fluctuations.

The aluminum alloy connecting pipe is an oil-blocking structure.

The material of the copper nose is T1 pure copper or T2 pure copper.

The copper nose is L-shaped, including a base plate connected to the circuit breaker and a connecting column connected to the base plate, and the other end of the connecting column is connected to the copper-aluminum transition piece. Preferably, the connecting post has the same diameter as the copper-aluminum transition piece.

A method for preparing an Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, comprising the following steps:

A. Casting of semi-finished products: take the raw material components of the aluminum alloy connecting pipe, melt them and cast them into shape to obtain the semi-finished aluminum alloy connecting pipes, take the raw materials of the copper-aluminum transition piece, melt them and cast them into shape, and obtain the semi-finished copper-aluminum transition piece;

B. Casting of copper nose: take TI pure copper or T2 pure copper, melt it and cast it to get copper nose;

C. Optimization treatment: the semi-finished product obtained in step A is subjected to homogenization treatment, intermittent annealing treatment, and aging treatment in sequence to obtain aluminum alloy connecting pipes and copper-aluminum transition pieces. The specific operations are as follows:

①. Optimal treatment of aluminum alloy connecting pipe semi-finished products: put the aluminum alloy connecting pipe semi-finished products at a temperature of 470-580 ° C, and homogenize them for 4-14 hours; then perform intermittent annealing treatment on the homogenized aluminum alloy connecting pipe semi-finished products , at a temperature of 290-360°C, keep warm for 1-5h and then cool down, then keep warm for 2-4h after the temperature drops to 170-210°C, and cool; Aging treatment is carried out in a uniform electric field of 15KV/cm, the temperature of the aging treatment is controlled at 270-330°C, and the aging treatment time is 6-21h;

②. Optimizing treatment of the semi-finished copper-aluminum transition piece: place the semi-finished copper-aluminum transition piece at 480-

Homogenize at 540°C for 6-12 hours; then perform intermittent annealing on the semi-finished copper-aluminum transition piece after homogenization, hold at 300-340°C for 2-6 hours and then cool down until the temperature drops to 180- After holding at 220°C for 2-3h, cool down; then perform aging treatment on the semi-finished copper-aluminum transition piece that has undergone intermittent annealing treatment in a uniform electric field with an electric field strength of 5-15KV/cm, and control the aging treatment temperature at 280-310°C , the aging treatment time is 9-15h;

D. Preparation of copper-aluminum transition terminal: The aluminum alloy connecting pipe, copper-aluminum transition piece, and copper nose are welded into an integrated structure by friction welding technology to obtain a copper-aluminum transition terminal.

The beneficial effects of the present invention are: the copper-aluminum transition piece is designed on the copper-aluminum transition terminal. When the aluminum alloy connection pipe transitions to the copper nose, due to the addition of the copper-aluminum transition piece, the aluminum alloy connection pipe and the copper nose The transition between them is more stable, the creep resistance is enhanced, and the power output is more stable. At the same time, due to the addition of copper-aluminum transition pieces, the over-current capacity is improved, and the bottleneck effect of the transmission in the copper-aluminum transition area during power transmission is eliminated. The structural problems of the aluminum transition piece improve the reliability of the connection, reduce the transmission resistance, reduce the heat loss, and prolong the life of the power facility. The copper-aluminum transition terminal of the present invention has extremely small resistance, extremely low electric loss, excellent electrical performance, mechanical property, mechanical property and corrosion resistance, and the copper-aluminum transition terminal of the present invention is extremely flexible and convenient in practical application, and has a wide range of applications. adaptability.

The preparation method of the invention is simple and easy to operate, and the prepared copper-aluminum transition terminal has high yield, good stability and reliable quality. The key to this preparation method lies in the optimized treatment of the semi-finished aluminum alloy connecting pipe and the semi-finished copper-aluminum transition piece. Through the optimized treatment, the dendrite segregation situation during casting and solidification of the aluminum alloy is solved, and the distribution of components in the grain boundary and within the grain is eliminated. uneven phenomenon. The homogenization treatment promotes the dissolution of the eutectic phase of the alloy, makes the distribution of the chemical composition of the alloy tend to be uniform, and the structure will reach a state close to equilibrium, improving the shape and distribution of the phases in the alloy, improving the plasticity of the alloy, and increasing the alloying elements (except The solid solubility of other elements other than aluminum) in the matrix (aluminum) increases the strength of the alloy, and finally improves the processing performance and end-use performance of the alloy; the time and temperature of the homogenization treatment in the present invention are the long-term creativity of the invention. According to the conclusion of the research, in the case of the homogenization treatment time and temperature, the diffusion of alloy elements is realized, the dendrite segregation is eliminated, the distribution from the grain boundary to the grain tends to be stable, and the residual phase on the grain boundary is also basically dissolved. . Through intermittent annealing treatment, the deformation resistance is reduced, overheating and overburning are avoided, the corrosion resistance of aluminum alloy is improved, the formation of layered structure is prevented, the anisotropy between components is weakened, and the strength and strength of aluminum alloy are further improved. Plasticity, eliminates the internal stress and damage to the microstructure during machining, optimizes the crystal structure, restores the electrical properties of the wire, optimizes the mechanical properties, and maintains good tensile properties, flexibility and fatigue resistance of the material Matching; because the aluminum alloy connecting pipe semi-finished product and the copper-aluminum transition piece semi-finished product contain Mn element, after intermittent annealing treatment, under the annealing conditions given by the present invention, form Al ₆ Mn intermetallic compound, they can stabilize dislocation, sub Substructures such as grain boundaries greatly increase the shear stress required for dislocation slip, hinder dislocation movement, and are conducive to high-temperature deformation heat treatment, which can promote the uniform distribution of the second phase in the aging process, and provide a good foundation for copper-aluminum alloy terminals in the application process. Provides a guarantee for stability under moderate temperature changes. Then, the annealed aluminum alloy is subjected to aging treatment in a uniform electric field. Through the aging treatment, the properties of the entire material can be evenly distributed, and various performance indicators can achieve excellent matching; due to the existence of copper elements, in the aging treatment process Among them, the solid solution strengthening and dispersion strengthening of the θ phase formed by copper and aluminum can be strengthened, the tensile strength and yield strength of the aluminum alloy can be improved, and the mechanical properties of the aluminum alloy can be further improved.

The performance analysis of each alloy element in the aluminum alloy connecting pipe and the copper-aluminum transition piece of the present invention is as follows:

The invention is based on aluminum and adds a small amount of iron. Aluminum can form Al ₃ Fe with iron, and the precipitated Al ₃ Fe dispersed particles inhibit the creep deformation of the alloy. Part of Fe also forms AlFeRE compound with RE to precipitate, and the precipitated phase AlFeRE It can enhance the fatigue resistance of the alloy and the heat resistance of high temperature operation, and the rare earth compound precipitated phase can also increase the yield limit strength; the added copper element and aluminum form theta phase, and the theta phase acts as solid solution strengthening and dispersion strengthening, improving The tensile strength and yield strength of the aluminum alloy are improved; the rare earth elements, as surface active elements, can be concentrated and distributed on the grain boundaries, reducing the tension between phases and refining the grains. MnAl ₄ has the same potential as aluminum through the interaction of manganese and aluminum, which can effectively improve the corrosion resistance and weldability of the alloy; at the same time, as a high-temperature strengthening phase, manganese can increase the recrystallization temperature and inhibit the coarsening of recrystallization, which can realize Solid solution strengthening, supplementary strengthening and improving heat resistance of alloys. Sc has a strong metamorphic effect, can refine the grains in the weld melting zone, form a large lattice strain, effectively prevent the movement of dislocations and the growth of grains, inhibit recrystallization, and significantly reduce the tendency of welding cracks The addition of Sc element can reduce the tendency of thermal cracks in the welding process of the alloy caused by the addition of Cu element, and significantly improve the strength and welding performance of the alloy. Sc and Al form a co-pattern, which is conducive to the crystal rotation to a consistent orientation to form a texture. , so that the strength of the aluminum alloy connecting pipe and the copper-aluminum transition piece is greatly improved while the electrical conductivity is basically unchanged. These coherent particles prevent the migration and merging of subgrain boundaries composed of two-dimensional dislocation networks, thereby causing a strong substructure strengthening effect on the alloy; Zr and Sc are selected to be added to the aluminum alloy at the same time because Zr and Sc Sc has a complementary effect, which makes the structure more uniform, thereby improving its strength and welding performance to a certain extent. The specific analysis shows that Zr can dissolve in the Al ₃ Sc phase to a large extent and form the Al ₃ (Sc ₁ -xZrx) phase, which has little difference from A1 ₃ Sc due to its lattice type and lattice parameters, so Not only maintains all the excellent properties of Al ₃ Sc, but also has a much smaller aggregation tendency than Al ₃ Sc phase under high temperature heating, and the formation of Al ₃ (Sc ₁ -xZrx) phase largely ensures the strengthening effect and inhibits recrystallization Effect, even if the Al ₃ (Sc ₁ -xZrx) intermetallic compound is annealed at high temperature, it still does not grow significantly, and maintains a coherent relationship with the matrix, which overcomes the coherent or semi-coherent relationship of the general age-hardening high-temperature aluminum alloy at high temperature. The disadvantage of losing the co-lattice due to the transition from the lattice phase to the equilibrium phase. Therefore, adding Zr at the same time as adding Sc can improve the beneficial properties of aluminum alloy on the one hand, and reduce the amount of expensive Sc added on the other hand; Toughness and stress corrosion resistance, due to its less quenching sensitivity, Zr can also improve the hardenability and weldability of the alloy. Rare earth elements, as surface active elements, can be concentrated and distributed on the grain boundaries, reducing the tension between phases and refining the grains. The invention is beneficial to the improvement of the comprehensive performance of the aluminum alloy through the selection and content control of the alloy elements, thereby ensuring the smooth transition of the cable conductor to the aluminum alloy connecting pipe and the copper-aluminum transition piece. The addition of V (vanadium) can further improve the smelting or sintering performance of the alloy, inhibit the grain growth, obtain a uniform and fine grain structure, reduce the brittleness of the alloy, and improve the comprehensive mechanical properties of the alloy; at the same time, after adding metal vanadium , the new phase Al ₅ V ₂ is formed in the alloy, and the β phase in the alloy is refined, and the original network distribution becomes intermittent uniform distribution, and the number decreases. The addition of the alloying element Sn can reduce the resistance of the passivation film on the aluminum surface and cause pores on the passivation film on the aluminum surface. The alloying element Sn has a high hydrogen overpotential, which can effectively inhibit hydrogen evolution corrosion and form a low co-existence with other alloying elements. The molten mixture destroys the passivation film on the aluminum surface; at the same time, tin can form Al ₉ Sn ₇ , Al ₆ Sn ₅ , Al ₅ Sn ₂ , Al ₃ Sn ₄ and other alloy compounds in the melt, forming high-temperature strengthening phases, improving The thermal stability and high-temperature creep resistance of the alloy can be improved, and the corrosion resistance of the alloy at room temperature or high temperature can be effectively improved.

In the present invention, by controlling the dosage ratio of Sc-Zr-Mn-RE, adding it to the aluminum alloy can significantly refine the crystal grains, inhibit recrystallization, increase the stability of the polygonal structure, and make the aluminum alloy grain The grain boundary precipitation phase is finer and more uniform, which is beneficial to reduce the electrode potential difference between the grain boundary and the grain, so that the corrosion is uniform, and the corrosion tendency of the grain boundary is reduced, thereby improving the corrosion resistance of the copper-aluminum transition terminal and maintaining the excellent aluminum alloy. At the same time as the conductivity, the strength, corrosion resistance and welding performance of the copper-aluminum transition terminal are significantly improved.

The simultaneous existence of Mn-Sc in the present invention can significantly refine the crystal grains and form fine dispersed precipitates. Because there are a large amount of such dispersed phases in the alloy, the growth of the crystal grains is also hindered and recrystallization is inhibited, so it can significantly Increase the recrystallization temperature, extend the recrystallization incubation period, reduce the recrystallization speed, and significantly improve its strength, corrosion resistance and welding performance while maintaining the excellent electrical conductivity of the aluminum alloy.

The addition of Fe and Mg elements to the aluminum matrix can significantly reduce the tendency of welding cracks, combined with Sc-Zr-Mn-RE can effectively inhibit the recrystallization of the heat-affected zone, and directly transition from the subgrain structure of the matrix to the casting of the weld. state zone, so that the transition zone or heat-affected zone of the weld that should have recrystallized structure does not have recrystallized structure. After adding Fe and Mg elements to the aluminum alloy, a large number of fine, dispersed and coherent particles are precipitated in the matrix. Particles, coherent particles have high thermal stability, and still exist in the heat-affected zone of the alloy, and the heat-affected zone is the weak part of the welded joint, so Fe and Mg can significantly reduce the thermal crack sensitivity of aluminum alloys and improve Solderability and weld strength of copper-aluminum transition terminals and their stress corrosion resistance.

Adding copper and manganese to the aluminum base can effectively prevent the brittle phase formed between copper and aluminum, so that the aluminum alloy and the copper end face can be metallurgically combined during friction welding, thereby improving the comprehensive performance of the copper-aluminum transition terminal. Adding Mn to the aluminum base at the same time can significantly improve the corrosion resistance of the aluminum alloy and further improve the comprehensive performance of the copper-aluminum transition terminal.

Sr, Ni, and Zn are also added to the chemical composition of the copper-aluminum transition piece. The addition of these elements ensures the smooth transition of the current from the aluminum alloy connecting pipe to the copper nose. The nickel and copper in the copper-aluminum transition piece can be infinitely dissolved. When nickel is added to the aluminum alloy, the Cu of the copper head of the terminal diffuses and dissolves to the Ni of the aluminum part, and at the same time, the Ni contained in the aluminum part diffuses and dissolves to the Cu on the side of the copper head, which further effectively prevents the formation of brittle phases between aluminum and copper, greatly greatly Improve the mutual solubility of aluminum and copper, so that the metallurgical combination of aluminum alloy and copper end face during friction welding, thereby improving the overall performance of the joint, adding an appropriate amount of nickel to the aluminum alloy, can also form a dense corrosion protective film with a certain thickness on the aluminum surface , to slow down the external corrosion and further increase its corrosion resistance; zinc and Al form REAl ₂ Zn ₃ , Fe ₃ Al ₂ Zn and other metal compounds to improve the tensile properties of the alloy, and to a certain extent effective Improve the high-temperature corrosion resistance of aluminum alloys, and further enhance the creep resistance of the transition zone from aluminum alloy tubes to copper noses; strontium can form Al ₇ Sr ₈ , Al ₄ Sr ₃ , AlSr ₂ and AlSr ₃ in the melt A variety of alloying elements can play a role in high temperature strengthening, improve high temperature creep performance, and provide a guarantee for the smooth transition of current.

Description of drawings

Fig. 1 is the structural representation of embodiment 1.

Figure 2 is a cross-sectional view along the line A-A of Figure 1

FIG. 3 is a schematic structural view of Embodiment 2.

Fig. 4 is a sectional view taken along line A-A of Fig. 3 .

FIG. 5 is a schematic structural view of Embodiment 3.

Fig. 6 is a sectional view taken along line A-A of Fig. 5 .

In the accompanying drawings, 1 represents the aluminum alloy connecting pipe, 2 represents the copper nose, 3 represents the copper-aluminum transition piece, 4 represents the bottom plate, and 5 represents the connecting column.

detailed description

The present invention mainly creatively improves the copper-aluminum transition terminal from the following aspects: 1. Improve environmental pollution (electrochemical effect), thereby improving the service life of the copper-aluminum transition terminal, the contact surface of the two metals of copper and aluminum and the moisture and carbon dioxide in the air Under the action of other impurities, it is easy to form electrolyte, produce battery effect, produce galvanic corrosion, cause the resistance of copper and aluminum transition joints to increase, generate heat, oxidize, and even break; 2. The current carrying capacity of the joint is improved to ensure the stability of the work 3. The improvement of the processing technology ensures the quality of the copper-aluminum transition terminal; 4. The change of the structure of the copper-aluminum transition terminal (the design of the copper-aluminum transition piece) improves the structural strength and avoids the occurrence of fracture damage. Examples further illustrate the present invention.

Example 1

As shown in Figure 1-2, the Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal includes an aluminum alloy connecting tube 1 connected to the cable conductor, and a copper lug 2 connected to the other end of the aluminum alloy connecting tube 1. The aluminum alloy connecting pipe 1 is an oil-blocking structure with a built-in conductive paste. The aluminum alloy connecting pipe 1 is provided with an inner connecting hole, and the cable conductor is inserted into the inner connecting hole. The cross-sectional shape of the inner connecting hole is circular, fan-shaped, tile-shaped, semi-circular, or a shape corresponding to the cross-section of the cable. The copper nose 2 is L-shaped, including a bottom plate 4 connected to the circuit breaker and a connecting column 5 connected to the bottom plate 4. The other end of the connecting column 5 is connected to the The copper-aluminum transition piece 3 is connected, and the connecting column 5 and the bottom plate 4 are designed at an angle of 100-120°. This design is due to the influence of long-term wire traction and natural environmental factors on the copper-aluminum transition terminal. The welding surface will bear the bending internal force , in order to further improve the pressure bearing capacity and prevent the weld seam in the copper-aluminum transition zone from being broken due to external pressure, a copper-aluminum transition piece 3 is arranged between the aluminum alloy connecting pipe 1 and the copper nose 2, and the copper-aluminum transition piece 3 is Aluminum alloy with columnar solid structure, the diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe.

The copper-aluminum transition piece contains by weight percentage: Fe0.4%, Cu1.0%, Mg0.2%, Mn0.2%, Sc0.02%, Sn0.002%, RE0.5%, V0.03 %, Zr0.006%, Sr0.002%, Ni0.015%, Zn0.0015%, and the balance is aluminum.

The material composition of the aluminum alloy connecting pipe is the same as that of the connected cable conductor.

The material of the copper nose is T2 pure copper.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: IACS is the same as the aluminum alloy cable conductor.

Copper-aluminum transition piece: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 130MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate ≥ 93 %, 400h corrosion resistance mass loss less than 0.23g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027469.

Example 2

As shown in Figure 3-4, the Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal includes an aluminum alloy connecting tube 1 connected to the cable conductor, and a copper lug 2 connected to the other end of the aluminum alloy connecting tube 1. The aluminum alloy connecting pipe 1 is an oil-blocking structure with a built-in conductive paste. The aluminum alloy connecting pipe 1 is provided with an inner connecting hole, and the cable conductor is inserted into the inner connecting hole. The cross-sectional shape of the inner connecting hole is circular, fan-shaped, tile-shaped, semi-circular, or a shape corresponding to the cross-section of the cable. The copper nose 2 is L-shaped, including a bottom plate 4 connected to the circuit breaker and a connecting column 5 connected to the bottom plate 4. The other end of the connecting column 5 is connected to the The copper-aluminum transition piece 3 is connected, and the connecting column 5 and the bottom plate 4 are designed at an angle of 90°. The angle of this design is too small, which is not conducive to the fixing of the wiring nose 1. If the angle is too large, the contact area of the connection is small and it is easy to break. To further improve the pressure bearing capacity and avoid the weld seam in the copper-aluminum transition area from being broken due to external pressure, a copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2, and the copper-aluminum transition piece 3 is a columnar solid The structure is made of aluminum alloy, the diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe, and the diameter of the connecting column 5 is larger than the diameter of the copper-aluminum transition piece 3 . The material of the copper nose is T2 pure copper.

The copper-aluminum transition piece contains by weight percentage: Fe0.2%, Cu0.5%, Mg0.03%, Mn0.05%, Sc0.01%, Sn0.001%, RE0.1%, V0.01 %, Zr0.005%, Sr0.001%, Ni0.01%, Zn0.001%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.3%, Cu0.01%, Mg0.01%, Mn0.01%, Sc0.02%, Sn0.002%, RE0.1%, V0.02% , Zr0.003%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity ≥ 63% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ° C, heat resistance test strength residual rate ≥ 93 %, 400h corrosion resistance mass loss less than 0.3g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027363.

Copper-aluminum transition piece: conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ° C, heat resistance test strength residual rate ≥ 95 %, 400h corrosion resistance mass loss less than 0.23g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.026356.

Example 3

As shown in Figure 5-6, the Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal includes an aluminum alloy connecting tube 1 connected to the cable conductor, and a copper lug 2 connected to the other end of the aluminum alloy connecting tube 1. The aluminum alloy connecting pipe 1 is an oil-blocking structure with a built-in conductive paste. The aluminum alloy connecting pipe 1 is provided with an inner connecting hole, and the cable conductor is inserted into the inner connecting hole. The cross-sectional shape of the inner connecting hole is circular, fan-shaped, tile-shaped, semi-circular, or a shape corresponding to the cross-section of the cable. The copper nose 2 is L-shaped, including a bottom plate 4 connected to the circuit breaker and a connecting column 5 connected to the bottom plate 4. The other end of the connecting column 5 is connected to the The copper-aluminum transition piece 3 is connected, and the connecting column 5 and the bottom plate 4 are designed at an angle of 90°. The angle of this design is too small, which is not conducive to the fixing of the wiring nose 1. If the angle is too large, the contact area of the connection is small and it is easy to break. To further improve the pressure bearing capacity and avoid the weld seam in the copper-aluminum transition area from being broken due to external pressure, a copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2, and the copper-aluminum transition piece 3 is a columnar solid The structure is made of aluminum alloy, the diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe, and the diameter of the connecting column 5 is equal to the diameter of the copper-aluminum transition piece 3 . The material of the copper nose is T2 pure copper.

The copper-aluminum transition piece contains by weight percentage: Fe0.6%, Cu1.4%, Mg0.4%, Mn0.5%, Sc0.03%, Sn0.003%, RE0.6%, V0.05 %, Zr0.008%, Sr0.003%, Ni0.02%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.7%, Cu0.4%, Mg0.2%, Mn0.08%, Sc0.06%, Sn0.005%, RE0.6%, V0.08% , Zr0.005%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity ≥ 64% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 31%, tensile strength ≥ 130MPa, long-term operation heat resistance temperature ≥ 250 ° C, heat resistance test strength residual rate reaches 96 %, 400h corrosion resistance mass loss less than 0.29g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027656.

Copper-aluminum transition piece: electrical conductivity ≥ 67% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 95 %, 400h corrosion resistance mass loss less than 0.24g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026752.

Example 4

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting pipe 1 connected to the cable conductor, a copper nose 2 connected to the other end of the aluminum alloy connecting pipe 1, and the aluminum alloy connecting pipe 1 is a plug Oil-type structure, built-in conductive paste, aluminum alloy connecting pipe 1 is provided with an inner connection hole, and the cable conductor is inserted into the inner connection hole. The cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or The shape corresponding to the cross section of the cable, the copper lug 2 is L-shaped, including the base plate 4 connected to the circuit breaker and the connecting column 5 connected to the base plate 4, the other end of the connecting column 5 is connected to the copper-aluminum transition piece 3, connected The column 5 and the base plate 4 are designed at an angle of 100-120°. This design is mainly due to the long-term wire traction of the copper-aluminum transition terminal and the influence of natural and other environmental factors. The welding surface will bear the bending internal force. In order to further improve the pressure bearing capacity To avoid fracture of the weld seam in the copper-aluminum transition zone due to external pressure, a copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2, the copper-aluminum transition piece 3 is an aluminum alloy with a columnar solid structure, The diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe.

The copper-aluminum transition piece contains by weight percentage: Fe0.3%, Cu0.6%, Mg0.05%, Mn0.08%, Sc0.02%, Sn0.002%, RE0.5%, V0.02 %, Zr0.006%, Sr0.002%, Ni0.02%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.5%, Cu0.03%, Mg0.03%, Mn0.02%, Sc0.03%, Sn0.003%, RE0.6%, V0.03% , Zr0.004%, and the balance is aluminum.

The material of the copper nose is T2 pure copper.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity ≥ 62% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 140MPa, long-term operation heat resistance temperature ≥ 240 ° C, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.28g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027832.

Copper-aluminum transition piece: conductivity ≥ 67% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 35%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 270 ° C, heat resistance test strength residual rate reaches 95 %, 400h corrosion resistance mass loss less than 0.23g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026537.

Example 5

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting pipe 1 connected to the cable conductor, a copper nose 2 connected to the other end of the aluminum alloy connecting pipe 1, and the aluminum alloy connecting pipe 1 is a plug Oil-type structure, built-in conductive paste, aluminum alloy connecting pipe 1 is provided with an inner connection hole, and the cable conductor is inserted into the inner connection hole. The cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or The shape corresponding to the cross section of the cable, the copper lug 2 is L-shaped, including the base plate 4 connected to the circuit breaker and the connecting column 5 connected to the base plate 4, the other end of the connecting column 5 is connected to the copper-aluminum transition piece 3, connected The angle between column 5 and base plate 4 is designed to be 90°. If the included angle is too small, it is not conducive to the fixation of wiring nose 1. If the included angle is too large, the contact area of the connection is small and it is easy to break. In order to further improve the pressure bearing capacity, avoid copper The weld seam in the aluminum transition area is broken due to external pressure. A copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2. The copper-aluminum transition piece 3 is an aluminum alloy with a columnar solid structure. The diameter of the piece is smaller than the diameter of the aluminum alloy connecting pipe, and the diameter of the connecting column 5 is larger than that of the copper-aluminum transition piece 3 . The material of the copper nose is T2 pure copper.

The copper-aluminum transition piece contains by weight percentage: Fe0.4%, Cu0.7%, Mg0.07%, Mn0.1%, Sc0.03%, Sn0.003%, RE0.4%, V0.03 %, Zr0.007%, Sr0.003%, Ni0.01%, Zn0.001%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.7%, Cu0.05%, Mg0.05%, Mn0.03%, Sc0.04%, Sn0.004%, RE0.5%, V0.04% , Zr0.005%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity ≥ 63% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 210 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.28g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027967.

Copper-aluminum transition piece: electrical conductivity ≥ 66% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 95 %, 400h corrosion resistance mass loss less than 0.24g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026456.

Example 6

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting pipe 1 connected to the cable conductor, a copper nose 2 connected to the other end of the aluminum alloy connecting pipe 1, and the aluminum alloy connecting pipe 1 is a plug Oil-type structure, built-in conductive paste, aluminum alloy connecting pipe 1 is provided with an inner connection hole, and the cable conductor is inserted into the inner connection hole. The cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or The shape corresponding to the cross section of the cable, the copper lug 2 is L-shaped, including the base plate 4 connected to the circuit breaker and the connecting column 5 connected to the base plate 4, the other end of the connecting column 5 is connected to the copper-aluminum transition piece 3, connected The angle between column 5 and base plate 4 is designed to be 90°. If the included angle is too small, it is not conducive to the fixation of wiring nose 1. If the included angle is too large, the contact area of the connection is small and it is easy to break. In order to further improve the pressure bearing capacity, avoid copper The weld seam in the aluminum transition area is broken due to external pressure. A copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2. The copper-aluminum transition piece 3 is an aluminum alloy with a columnar solid structure. The diameter of the piece is smaller than the diameter of the aluminum alloy connecting pipe, and the diameter of the connecting column 5 is equal to the diameter of the copper-aluminum transition piece 3. The material of the copper nose is T2 pure copper.

The copper-aluminum transition piece contains by weight percentage: Fe0.5%, Cu0.8%, Mg0.09%, Mn0.15%, Sc0.02%, Sn0.002%, RE0.3%, V0.04 %, Zr0.008%, Sr0.002%, Ni0.02%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.9%, Cu0.08%, Mg0.08%, Mn0.04%, Sc0.05%, Sn0.005%, RE0.4%, V0.05% , Zr0.004%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.26g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.027838.

Copper-aluminum transition piece: electrical conductivity ≥ 67% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 95 %, 400h corrosion resistance mass loss less than 0.24g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026368.

Example 7

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting pipe 1 connected to the cable conductor, a copper nose 2 connected to the other end of the aluminum alloy connecting pipe 1, and the aluminum alloy connecting pipe 1 is a plug Oil-type structure, built-in conductive paste, aluminum alloy connecting pipe 1 is provided with an inner connection hole, and the cable conductor is inserted into the inner connection hole. The cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or The shape corresponding to the cross section of the cable, the copper lug 2 is L-shaped, including the base plate 4 connected to the circuit breaker and the connecting column 5 connected to the base plate 4, the other end of the connecting column 5 is connected to the copper-aluminum transition piece 3, connected The column 5 and the base plate 4 are designed at an angle of 100-120°. This design is mainly due to the long-term wire traction of the copper-aluminum transition terminal and the influence of natural and other environmental factors. The welding surface will bear the bending internal force. In order to further improve the pressure bearing capacity To avoid fracture of the weld seam in the copper-aluminum transition zone due to external pressure, a copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2, the copper-aluminum transition piece 3 is an aluminum alloy with a columnar solid structure, The diameter of the copper-aluminum transition piece is smaller than the diameter of the aluminum alloy connecting pipe.

The copper-aluminum transition piece contains by weight percentage: Fe0.25%, Cu0.9%, Mg0.1%, Mn0.2%, Sc0.01%, Sn0.001%, RE0.2%, V0.05 %, Zr0.007%, Sr0.001%, Ni0.01%, Zn0.001%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe0.8%, Cu0.1%, Mg0.1%, Mn0.05%, Sc0.06%, Sn0.004%, RE0.3%, V0.06% , Zr0.003%, and the balance is aluminum.

The material of the copper nose is T2 pure copper.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.28g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027747.

Copper-aluminum transition piece: electrical conductivity ≥ 68% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.26g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.026852.

Example 8

Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including an aluminum alloy connecting pipe 1 connected to the cable conductor, a copper nose 2 connected to the other end of the aluminum alloy connecting pipe 1, and the aluminum alloy connecting pipe 1 is a plug Oil-type structure, built-in conductive paste, aluminum alloy connecting pipe 1 is provided with an inner connection hole, and the cable conductor is inserted into the inner connection hole. The cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or The shape corresponding to the cross section of the cable, the copper lug 2 is L-shaped, including the base plate 4 connected to the circuit breaker and the connecting column 5 connected to the base plate 4, the other end of the connecting column 5 is connected to the copper-aluminum transition piece 3, connected The angle between column 5 and base plate 4 is designed to be 90°. If the included angle is too small, it is not conducive to the fixation of wiring nose 1. If the included angle is too large, the contact area of the connection is small and it is easy to break. In order to further improve the pressure bearing capacity, avoid copper The weld seam in the aluminum transition area is broken due to external pressure. A copper-aluminum transition piece 3 is provided between the aluminum alloy connecting pipe 1 and the copper nose 2. The copper-aluminum transition piece 3 is an aluminum alloy with a columnar solid structure. The diameter of the piece is smaller than the diameter of the aluminum alloy connecting pipe, and the diameter of the connecting column 5 is larger than that of the copper-aluminum transition piece 3 . The material of the copper nose is T2 pure copper.

The copper-aluminum transition piece contains by weight percentage: Fe0.35%, Cu1.0%, Mg0.15%, Mn0.25%, Sc0.02%, Sn0.002%, RE0.6%, V0.04 %, Zr0.006%, Sr0.002%, Ni0.02%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.0%, Cu0.15%, Mg0.11%, Mn0.06%, Sc0.05%, Sn0.003%, RE0.2%, V0.07% , Zr0.004%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.27g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027345.

Copper-aluminum transition piece: conductivity ≥ 67% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ° C, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.25g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.026283.

Example 9

The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal differs from Example 3 in that:

The copper-aluminum transition piece contains by weight percentage: Fe0.45%, Cu1.1%, Mg0.2%, Mn0.3%, Sc0.03%, Sn0.001%, RE0.5%, V0.03 %, Zr0.005%, Sr0.003%, Ni0.01%, Zn0.001%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.2%, Cu0.2%, Mg0.13%, Mn0.07%, Sc0.04%, Sn0.002%, RE0.3%, V0.06% , Zr0.005%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 64% IACS, higher than that of aluminum alloy cable conductors, elongation at break ≥ 30%, tensile strength ≥ 110MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.31g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027843.

Copper-aluminum transition piece: conductivity ≥ 68% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 130MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.27g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.026921.

Example 10

The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal differs from Embodiment 4 in that:

The copper-aluminum transition piece contains by weight percentage: Fe0.2%, Cu1.2%, Mg0.25%, Mn0.35%, Sc0.02%, Sn0.002%, RE0.4%, V0.02 %, Zr0.006%, Sr0.002%, Ni0.02%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.4%, Cu0.25%, Mg0.15%, Mn0.06%, Sc0.03%, Sn0.003%, RE0.4%, V0.05% , Zr0.004%, and the balance is aluminum. The material of the copper nose is T2 pure copper.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.29g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.027598.

Copper-aluminum transition piece: conductivity ≥ 69% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.26g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026157.

Example 11

The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal differs from Example 5 in that:

The copper-aluminum transition piece contains by weight percentage: Fe0.3%, Cu1.3%, Mg0.3%, Mn0.4%, Sc0.01%, Sn0.001%, RE0.3%, V0.01 %, Zr0.007%, Sr0.001%, Ni0.01%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.6%, Cu0.3%, Mg0.17%, Mn0.05%, Sc0.02%, Sn0.004%, RE0.5%, V0.04% , Zr0.003%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 65% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.28g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.02788.

Copper-aluminum transition piece: electrical conductivity ≥ 68% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.26g/m ² ·hr, 20°C resistivity (Ω·mm ² /m): average value ≤0.026928.

Example 12

The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal differs from Example 5 in that:

The copper-aluminum transition piece contains by weight percentage: Fe0.4%, Cu1.0%, Mg0.35%, Mn0.45%, Sc0.02%, Sn0.002%, RE0.2%, V0.02 %, Zr0.005%, Sr0.002%, Ni0.01%, Zn0.002%, and the balance is aluminum.

The aluminum alloy connecting pipe contains by weight percentage: Fe1.0%, Cu0.35%, Mg0.19%, Mn0.04%, Sc0.04%, Sn0.003%, RE0.4%, V0.03% , Zr0.004%, and the balance is aluminum.

The copper-aluminum transition terminal of the above embodiment was subjected to 1000 times of thermal cycle test, tensile test of terminal and cable conductor, and 100-hour compression creep performance test, and the tested performance was much higher than that of GB/T9327-2008 and IEC61238-1:2003 The specific detection parameters are as follows:

Aluminum alloy connecting pipe: electrical conductivity ≥ 63% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 120MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 93 %, 400h corrosion resistance mass loss less than 0.29g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.02695.

Copper-aluminum transition piece: electrical conductivity ≥ 68% IACS, higher than aluminum alloy cable conductor, elongation at break ≥ 30%, tensile strength ≥ 150MPa, long-term operation heat resistance temperature ≥ 230 ℃, heat resistance test strength residual rate reaches 91 %, 400h corrosion resistance mass loss less than 0.25g/m ² ·hr, resistivity at 20°C (Ω·mm ² /m): average value ≤0.026318.

The further optimization scheme of Embodiment 1-12 of the present invention is: the material of the copper nose 2 is T1 pure copper, and T1 pure copper is selected. Compared with T2 pure copper, the resistance is extremely small, the power loss is extremely low, the electrical performance is improved, and it is not easy to occur Electric fire. In terms of service life, under the same conditions, the service life of copper-aluminum transition terminals using T1 pure copper is 1/4 longer than that of T2 pure copper, and the electrical properties, mechanical properties, mechanical properties and corrosion resistance of copper-aluminum transition terminals are all the same. substantial improvement.

The present invention also provides a method for preparing a high-performance aluminum alloy cable copper-aluminum transition terminal, comprising the following steps:

A. Preparation of semi-finished products: take the raw material components of the aluminum alloy connecting pipe, cast and form them after melting, and obtain the semi-finished aluminum alloy connecting pipe;

B, the preparation of copper nose: take TI pure copper or T2 pure copper, cast after melting, obtain copper nose;

C. Optimization processing: specific operations include:

①. Optimal treatment of aluminum alloy connecting pipe semi-finished products: put the aluminum alloy connecting pipe semi-finished products at a temperature of 470-580°C (preferably 500-520°C), and homogenize them for 4-14h (preferably 8-12h); then homogenize The processed aluminum alloy connecting pipe semi-finished product is subjected to intermittent annealing treatment, at a temperature of 290-360°C (preferably 310-330°C), kept for 1-5h (preferably 2-4h) and then cooled, and the temperature drops to 170-210°C ( Preferably 180-200°C), after heat preservation for 2-4h (preferably 3h), cooling; then the semi-finished aluminum alloy connecting pipe that has undergone intermittent annealing treatment is subjected to aging treatment in a uniform electric field with an electric field strength of 5-15KV/cm to control the aging The treatment temperature is 270-330°C (preferably 300-320°C), and the aging treatment time is 6-21h (preferably 12-18h);

②. Optimal treatment of the semi-finished copper-aluminum transition piece: place the semi-finished copper-aluminum transition piece at a temperature of 480-540°C (preferably 500-510°C), and homogenize it for 6-12h (preferably 8-10h); then homogenize The processed semi-finished copper-aluminum transition piece is subjected to intermittent annealing treatment, at a temperature of 300-340°C (preferably 310-320°C), kept warm for 2-6h (preferably 3-5h), and then lowered to 180-220°C ( Preferably 200-210°C), after heat preservation for 2-3h, cooling; then the semi-finished copper-aluminum transition piece that has undergone intermittent annealing treatment is subjected to aging treatment in a uniform electric field with an electric field strength of 5-15KV/cm, and the temperature of the aging treatment is controlled to 280-310°C (preferably 290-300°C), the aging treatment time is 9-15h (preferably 10-13h);

D. Preparation of copper-aluminum transition terminal: The aluminum alloy connecting pipe, copper-aluminum transition piece, and copper nose are welded into an integrated structure by friction welding technology to obtain a copper-aluminum transition terminal.

Homogenizing the aluminum alloy can ensure that its strength and ductility have a good match, so as to avoid the damage of the microstructure of the material and further affect the processing performance. In order to ensure uniform heating, optimize the microstructure of the alloy, and avoid internal structural defects caused by excessive heating or cooling during the processing of the alloy, the heating rate of the homogenization treatment can be controlled to 1-7°C/min. The present invention adopts intermittent step-by-step annealing treatment, and gradually lowers the temperature and cooling. This treatment method can eliminate the internal stress and damage to the microstructure generated in the machining process, optimize the crystal structure, restore the electrical properties of the wire, and optimize the mechanical properties. To maintain a good match in terms of tensile properties, flexibility and fatigue resistance of the material. Aging treatment on the basis of annealing treatment technology can further compensate for uneven heat conduction during annealing treatment, resulting in uneven distribution of internal and external properties of materials or local defects. Through aging treatment, the performance of the entire material can be evenly distributed, and the comprehensive indicators of various performances can achieve excellent matching. Therefore, the effective combination of annealing treatment and aging treatment plays a vital role in optimizing the overall performance of the material, and both are indispensable. The present invention preferably performs aging treatment in a high-intensity uniform electric field. The first aspect changes the arrangement, matching and migration of atoms, and the second aspect improves the solid solution degree of alloy elements, induces the uniform nucleation of T1 phase, and improves The yield strength of the alloy is improved; after the homogenized sample is subjected to aging treatment, the precipitates are uniformly dispersed and distributed, and the mechanical properties of the alloy are greatly improved; thirdly, the precipitation form and quantity of the fine crystal structure are changed, so that the material is solid-state and phase-transformed The shape, size, distribution and other orientations in the material can be controlled, thereby controlling the structure of the material, and finally obtaining excellent mechanical and electrical properties.

Comparative Example 1

A copper-aluminum transition terminal, comprising a pure aluminum connection tube connected to the cable conductor and a copper nose connected to the pure aluminum connection tube, the copper nose is made of T2 pure copper, the pure aluminum connection tube is an oil-blocking structure, and the built-in Conductive paste, the pure aluminum connecting tube is provided with an inner connecting hole, and the cable conductor is inserted into the inner connecting hole, and the cross-sectional shape of the inner connecting hole is circular, fan-shaped, tile-shaped, semi-circular or a shape corresponding to the cable cross-section , the copper nose includes a connecting column connected with a pure aluminum connecting pipe, and a base plate connected with the connecting column, and a bolt hole is opened on the base plate. The copper-aluminum transition terminal has poor creep resistance, and it is prone to skipping and fluctuations in the power transmission process, resulting in short circuit and over-burning. The contact resistance of the contact resistance is large, resulting in heat generation, oxidation and joint fracture, and the service life is short.

The copper-aluminum transition terminal of the above-mentioned embodiment is subjected to a performance test, and the specific detection parameters are as follows:

Aluminum alloy connecting pipe: Conductivity 45% IACS is lower than aluminum alloy cable conductor, elongation at break 10%, tensile strength 80MPa, long-term operation heat resistance temperature 120°C, heat resistance test strength residual rate reaches 88%, 400h corrosion resistance Properties Mass loss ≥ 0.9g/m ² ·hr, resistivity (Ω·mm ² /m) at 20°C: average value 0.029635.

Comparative Example 2

A copper-aluminum transition terminal, comprising an aluminum alloy connecting pipe connected to a cable conductor and a copper nose connected to the aluminum alloy connecting pipe, the copper nose is made of T2 pure copper, and the aluminum alloy connecting pipe is an oil-blocking structure with a built-in Conductive paste, the aluminum alloy connection tube is provided with an inner connection hole, the cable conductor is inserted into the inner connection hole, and the cross-sectional shape of the inner connection hole is circular, fan-shaped, tile-shaped, semi-circular or a shape corresponding to the cable cross-section The copper nose includes a connecting column connected with an aluminum alloy connecting pipe, and a base plate connected with the connecting column, and a bolt hole is opened on the base plate. The copper-aluminum transition terminal has poor creep resistance, and it is prone to skipping and fluctuations in the power transmission process, resulting in short circuit and over-burning. The contact resistance of the contact resistance is large, resulting in heat generation, oxidation and joint fracture, and the service life is short.

The chemical composition of the aluminum alloy connecting pipe is: 0.048% iron; 0.019% copper; 0.03% zirconium; 0.04% silicon; 0.28% yttrium;

The copper-aluminum transition terminal of the above-mentioned embodiment is subjected to a performance test, and the specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity 55% IACS, lower than aluminum alloy cable conductor, elongation at break 12%, tensile strength 90MPa, long-term operation heat resistance temperature 150°C, heat resistance test strength residual rate reaches 89%, 400h resistance Corrosion performance Mass loss ≥ 0.79g/m ² ·hr, resistivity (Ω·mm ² /m) at 20°C: average value ≥ 0.028635.

Comparative Example 3

A copper-aluminum transition terminal, comprising a copper nose, an aluminum connection pipe connected to the copper nose, the aluminum connection pipe is connected to a cable conductor, and the aluminum connection pipe is provided with an inner connection hole; the cross-sectional shape of the inner connection hole is circular , fan-shaped, tile-shaped, semicircular and shapes corresponding to the cable cross-section, the chemical composition mass percentage of the aluminum connecting pipe is: Si≤0.12, Fe0.35-0.75, Cu0.15-0.25, Mg≤ 0.05, Zn≤0.05, B0.001-0.04, other elements individually ≤0.03, the sum of other elements ≤0.1, Al balance. The copper-aluminum transition terminal has poor creep resistance, and it is prone to skipping and fluctuations in the power transmission process, resulting in short circuit and over-burning. The contact resistance of the contact resistance is large, resulting in heat generation, oxidation and joint fracture, and the service life is short.

The copper-aluminum transition terminal of the above-mentioned embodiment is subjected to a performance test, and the specific detection parameters are as follows:

Aluminum alloy connecting pipe: tensile strength (MPa) 60-150, elongation 10%-20%, 20°C resistivity (Ω·mm2/m): average value ≤ 0.028264, 61.0 ≤ IACS ≤ 62.8.

Comparative Example 4

A copper-aluminum connection terminal, comprising an aluminum alloy tube and a copper head, characterized in that the aluminum alloy tube contains by weight percentage: Fe0.79%-0.8%, Cu0.13%-0.15%, Sc0.0029%- 0.0068%, Ni0.1%-0.3%, Si0.061%-0.062%, Al and other unavoidable impurities. The copper-aluminum transition terminal has poor creep resistance, and it is prone to skipping and fluctuations in the power transmission process, resulting in short-circuit and over-burning. The contact resistance is large, resulting in heat generation, oxidation and joint fracture, and the service life is short.

The copper-aluminum transition terminal of the above-mentioned embodiment is subjected to a performance test, and the specific detection parameters are as follows:

Aluminum alloy connecting pipe: conductivity 58% IACS, lower than aluminum alloy cable conductor, elongation at break 14%, tensile strength 100MPa, long-term operation heat resistance temperature 160°C, heat resistance test strength residual rate reaches 88%, 400h resistance Corrosion performance Mass loss ≥ 0.85g/m ² ·hr, resistivity (Ω·mm ² /m) at 20°C: average value ≥ 0.028745, IACS lower than aluminum alloy cable conductor.

The best preparation method of the copper-aluminum transition terminal of the present invention is to adopt the preparation method of the present invention. The copper-aluminum transition terminal of the present invention can also be processed by existing or conventional processing technology, and the performance is still higher than that of the comparative example. performance, but compared with the preparation method of the present invention, slightly worse from the performance. The aluminum alloy material of the present invention greatly improves the heat resistance of the aluminum alloy material by adding a variety of alloy elements and adopting heat treatment technology, so that the long-term operating temperature of the aluminum alloy material is 230°C, the creep phenomenon is small, and the tensile strength is maintained The 90% survival rate ensures that the mechanical properties change little under high temperature operation, and the fatigue resistance performance is also improved, which can avoid the loss of different degrees when used as a connecting terminal; and through heat treatment technology makes The flexibility of the alloy is quite good, which greatly improves the ductility of the aluminum alloy, and the elongation rate exceeds 30%, and it is not prone to loss due to the action of tension. Compared with the copper-aluminum transition terminal of the comparative example, on the basis that the copper noses are all made of T2 pure copper, the creep resistance of the present invention is improved by 42% compared with the comparative example 1, and compared with the comparative example 2- 4 The creep resistance has been improved by 5-10%, therefore, the safety performance of the copper-aluminum transition terminal of the present invention is higher; compared with Comparative Example 1, the corrosion resistance has been improved by 30%, compared with Comparative Example 2- 4 The corrosion resistance has been improved by 10-15%, the mechanical properties have been improved by 40% compared with Comparative Example 1, and 10-20% compared with 2-4; the electrical properties have been improved by 30% compared with Comparative Example 1 %, increased by 10-15% compared to 2-4; the heat resistance increased by 50% compared to Comparative Example 1, and increased by 10-25% compared to 2-4.

Claims (10)

1. Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal, including the aluminum alloy connecting tube (1) connected to the cable conductor, and the copper nose (2) connected to the other end of the aluminum alloy connecting tube (1). It is characterized in that a copper-aluminum transition piece (3) is provided between the aluminum alloy connecting pipe (1) and the copper nose (2), the copper-aluminum transition piece (3) is an aluminum alloy with a columnar solid structure, and the copper The aluminum transition piece (3) contains by weight percentage: Fe0.2-0.6%, Cu0.5-1.4%, Mg0.03-0.4%, Mn0.05-0.5%, Sc0.01-0.03%, Sn0.001- 0.003%, RE0.1-0.6%, V0.01-0.05%, Zr0.005-0.008%, Sr0.001-0.003%, Ni0.01-0.02%, Zn0.001-0.002%, and the balance is aluminum. 2. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the copper-aluminum transition piece (3) contains by weight percentage: Fe0.3-0.5%, Cu0.8-1.2%, Mg0.1-0.3%, Mn0.1-0.4%, Sc0.015-0.025%, Sn0.0015-0.0025%, RE0.2-0.4%, V0.02-0.04%, Zr0 .006-0.007%, Sr0.0015-0.0025%, Ni0.012-0.018%, Zn0.0013-0.0017%, and the balance is aluminum. 3. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the copper-aluminum transition piece (3) contains by weight percentage: Fe0.4%, Cu1. 0%, Mg0.2%, Mn0.2%, Sc0.02%, Sn0.002%, RE0.5%, V0.03%, Zr0.006%, Sr0.002%, Ni0.015%, Zn0. 0015%, and the balance is aluminum. 4. The Al-Fe-Mn-REE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the diameter of the copper-aluminum transition piece (3) is smaller than the diameter of the aluminum alloy connecting pipe (1) . 5. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the material composition of the aluminum alloy connecting pipe (1) is the same as that of the connected cable conductor. 6. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the aluminum alloy connecting pipe (1) contains by weight percentage: Fe0.3-1.7%, Cu0 .01-0.4%, Mg0.01-0.2%, Mn0.01-0.08%, Sc0.02-0.06%, Sn0.002-0.005%, RE0.1-0.6%, V0.02-0.08%, Zr0. 003-0.005%, the balance is aluminum. 7. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the aluminum alloy connecting pipe (1) is an oil-blocking structure. 8. The copper-aluminum transition terminal for Al-Fe-Mn-RE aluminum alloy cable according to claim 1, characterized in that: the material of the copper nose (2) is T1 pure copper or T2 pure copper. 9. The Al-Fe-Mn-RE aluminum alloy cable copper-aluminum transition terminal according to claim 1, characterized in that: the copper nose (2) is L-shaped, including a bottom plate (4) connected to the circuit breaker and the connection column (5) connected with the bottom plate (4), and the other end of the connection column (5) is connected with the copper-aluminum transition piece (3). 10. A method for preparing the copper-aluminum transition terminal of the Al-Fe-Mn-RE aluminum alloy cable according to claim 1, characterized in that it comprises the following steps: A. Casting of semi-finished products: Take the raw material components of the aluminum alloy connecting pipe (1), melt them and cast them into shape to obtain the semi-finished aluminum alloy connecting pipes, take the raw materials of the copper-aluminum transition piece (3), melt them and cast them to obtain copper-aluminum semi-finished transition piece; B. Casting of copper nose: take TI pure copper or T2 pure copper, melt it and cast it to get copper nose; C. Optimization treatment: the semi-finished product obtained in step A is subjected to homogenization treatment, intermittent annealing treatment, and aging treatment in sequence to obtain aluminum alloy connecting pipes and copper-aluminum transition pieces. The specific operations are as follows: ①. Optimal treatment of aluminum alloy connecting pipe semi-finished products: put the aluminum alloy connecting pipe semi-finished products at a temperature of 470-580 ° C, and homogenize them for 4-14 hours; then perform intermittent annealing treatment on the homogenized aluminum alloy connecting pipe semi-finished products , at a temperature of 290-360°C, keep warm for 1-5h and then cool down, then keep warm for 2-4h after the temperature drops to 170-210°C, and cool; Aging treatment is carried out in a uniform electric field of 15KV/cm, the temperature of the aging treatment is controlled at 270-330°C, and the aging treatment time is 6-21h; ②. Optimizing treatment of the semi-finished copper-aluminum transition piece: place the semi-finished copper-aluminum transition piece at 480- Homogenize at 540°C for 6-12 hours; then perform intermittent annealing on the semi-finished copper-aluminum transition piece after homogenization, hold at 300-340°C for 2-6 hours and then cool down until the temperature drops to 180- After holding at 220°C for 2-3h, cool down; then perform aging treatment on the semi-finished copper-aluminum transition piece that has undergone intermittent annealing treatment in a uniform electric field with an electric field strength of 5-15KV/cm, and control the aging treatment temperature at 280-310°C , the aging treatment time is 9-15h; D. Preparation of copper-aluminum transition terminal: The aluminum alloy connecting pipe, copper-aluminum transition piece, and copper nose are welded into an integrated structure by friction welding technology to obtain a copper-aluminum transition terminal.