A kind of Cu-Ag alloy wire reinforced with endogenous Ag fiber and preparation method thereof

Abstract

The present invention relates to the technical field of metal composite material processing and preparation, and provides a Cu-Ag alloy wire reinforced with endogenous Ag fiber and a preparation method thereof. The silver content in the copper-silver alloy is 4-8%, the oxygen content is below 3ppm, and the total content of copper and silver is above 99.995%. The preparation method comprises: preparing a copper-silver alloy rod by continuous casting under vacuum; preparing an initial copper-silver alloy wire by solid solution, aging, and drawing of the copper-silver alloy rod; recovery annealing of the initial copper-silver alloy wire; softening annealing of the initial copper-silver alloy wire, micro-wire drawing, and recovery annealing of the micro-wire. The diameter of the obtained copper-silver alloy wire is 0.1-0.3mm, and the diameter of the copper-silver alloy micro-wire is 0.02-0.05mm, and its tensile strength is not less than 1GPa, and its conductivity is not less than 80%IACS. The copper-silver alloy wire prepared by the present invention avoids problems such as uneven organization while reducing the silver content, and significantly improves its electrical conductivity and mechanical properties.

Description

Technical Field

[0001] The invention relates to the technical field of metal composite material processing and preparation, and in particular to an endogenous Ag fiber reinforced Cu-Ag alloy wire and a preparation method thereof. Background Art

[0002] As a high-strength and high-conductivity material, Cu-Ag alloy wires are widely used in the fields of high-intensity pulsed magnetic field conductor materials, lead frames, signal transmission lines, etc. With the development of social science and technology, the design and construction of high-performance pulsed magnetic fields has become a research focus, which requires the strength of Cu-Ag alloy to be greater than 1GPa and the conductivity to be greater than 80%.

[0003] At present, the preparation process of high-strength and high-conductivity Cu-Ag alloy mainly utilizes large deformation of the alloy to obtain. In Cu-Ag alloy, the strength of the alloy will increase with the increase of Ag mass fraction. However, its conductivity will decrease with the increase of Ag mass fraction. At the same time, the increase of Ag ratio will also greatly increase the production cost of the material. The patent with publication number CN111519062A discloses a high-strength and high-conductivity copper-silver alloy and its preparation method, which obtains copper-silver alloy ingots by electromagnetic stirring melting, refining and casting, and then obtains high-strength and high-conductivity copper-silver alloy by rolling, and the alloy composition is Cu (20-30) wt% Ag. The highest conductivity of the copper-silver alloy ingot obtained by this method is 83.5% IACS, and the tensile strength of the alloy after cold rolling is 790MPa. Its disadvantage is that the high Ag content in the alloy will produce a large amount of reticular eutectic structure, making the alloy structure uneven and reducing the conductivity of the material.

[0004] Therefore, improving the strength of low-Ag content alloys with good electrical conductivity will further improve the performance of the alloy. The patent with publication number CN109930016A discloses a method for preparing high-strength and high-conductivity copper-silver alloy fine wires, wherein a copper-silver alloy ingot is obtained by vacuum melting, and then a Cu-Ag alloy wire is obtained by vacuum extrusion, cold rolling, cold drawing, vacuum heat treatment, and cold drawing, and the alloy composition is Cu (1-6) wt% Ag. The copper-silver alloy obtained by this method has a strength of 1020MPa and an electrical conductivity of 72% IACS. The disadvantage of this method is that most of the Ag atoms in the alloy are still dissolved in the copper matrix, and the lattice distortion scattering caused by solid solution alloying reduces a certain degree of electrical conductivity.

[0005] In summary, how to simultaneously improve the strength and conductivity of low-Ag content alloy wires is still a problem that needs to be solved urgently in the field. Summary of the invention

[0006] In view of this, the present invention provides a Cu-Ag alloy wire reinforced with endogenous Ag fiber and a preparation method thereof. The present invention reduces the solid solubility of Ag atoms in the copper matrix through solid solution aging treatment, and at the same time makes the precipitated silver phase evenly dispersed in the copper matrix. After subsequent drawing, the copper matrix and the silver phase evolve into a fiber form, making the alloy a fiber-reinforced two-phase composite material, thereby obtaining a Cu-Ag alloy wire with a low Ag content and high strength and high conductivity.

[0007] In order to achieve the above-mentioned object of the invention, the present invention provides the following technical solutions:

[0008] A method for preparing an endogenous Ag fiber reinforced Cu-Ag alloy wire, wherein the endogenous Ag fiber reinforced Cu-Ag alloy wire comprises an endogenous Ag fiber reinforced Cu-Ag alloy wire and an endogenous Ag fiber reinforced Cu-Ag alloy fine wire;

[0009] The preparation method comprises the following steps:

[0010] Step 1: heating and melting copper and silver and then performing vacuum continuous casting to obtain a Cu-Ag alloy rod;

[0011] Step 2: performing solid solution treatment, aging and drawing on the Cu-Ag alloy rod in sequence to obtain an initial Cu-Ag alloy wire reinforced with endogenous Ag fibers;

[0012] Step 3: performing recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire material in step 2 to obtain an endogenous Ag fiber reinforced Cu-Ag alloy wire material;

[0013] Step 4: sequentially subjecting the initial Cu-Ag alloy wire reinforced with endogenous Ag fibers in step 2 to softening annealing, microfilament drawing and recovery annealing to obtain Cu-Ag alloy microfilaments reinforced with endogenous Ag fibers;

[0014] There is no time order restriction for step 3 and step 4;

[0015] The mass fraction of silver in the endogenous Ag fiber reinforced Cu-Ag alloy wire is 4-8%;

[0016] Preferably, the copper-silver alloy rod has a purity of >99.995% and an oxygen content of <3 ppm.

[0017] Preferably, the solution treatment temperature is 740°C to 780°C, the time is 2 to 4 hours, and the cooling method is water cooling; the aging temperature is 300 to 500°C, the time is 2 to 32 hours, and the cooling method is water cooling.

[0018] Preferably, the temperature of the softening annealing in step 4 is 300-500° C., and the annealing speed is 100-400 m / min.

[0019] Preferably, the recovery annealing temperature in steps 3 and 4 is 150-200° C., and the annealing speed is 100-200 m / min.

[0020] Preferably, the diameter of the endogenous Ag fiber reinforced Cu-Ag alloy wire is 0.1-0.3 mm; the diameter of the endogenous Ag fiber reinforced Cu-Ag alloy microfilament is 0.02-0.05 mm.

[0021] Preferably, the drawing in step 2 is cold drawing; during the drawing process in step 2, when the diameter of the drawn wire is greater than 0.8 mm, the deformation rate of the drawing pass is 10% to 20%, and the drawing speed is 30 to 70 m / min; when the diameter of the drawn wire is less than 0.8 mm, the deformation rate of the drawing pass is 8% to 12%, and the drawing speed is 400 to 800 m / min.

[0022] Preferably, the microfilament drawing in step 4 is cold drawing; the pass deformation rate of the microfilament drawing is 6% to 8%, and the drawing speed is 600 to 1000 m / min.

[0023] The present invention also provides a Cu-Ag alloy wire reinforced with endogenous Ag fibers prepared by the preparation method described in the above scheme.

[0024] Preferably, the tensile strength of the endogenous Ag fiber reinforced Cu-Ag alloy wire is greater than 1 GPa, and the electrical conductivity is 80% IACS.

[0025] The invention provides a method for preparing an endogenous Ag fiber reinforced Cu-Ag alloy wire. The endogenous Ag fiber reinforced Cu-Ag alloy wire comprises an endogenous Ag fiber reinforced Cu-Ag alloy wire and an endogenous Ag fiber reinforced Cu-Ag alloy micro-wire. The preparation method comprises the following steps: step 1: heating and melting copper and silver, and then performing vacuum down-drawing continuous casting to obtain a Cu-Ag alloy rod; step 2: performing solution aging and drawing on the Cu-Ag alloy rod in sequence to obtain an endogenous Ag fiber reinforced Cu-Ag alloy initial wire; step 3: performing recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire in step 2 to obtain an endogenous Ag fiber reinforced Cu-Ag alloy wire; step 4: performing softening annealing, micro-wire drawing and recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire in step 2 in sequence to obtain an endogenous Ag fiber reinforced Cu-Ag alloy micro-wire. The present invention prepares a copper-silver alloy rod by a downward continuous casting method, which can effectively eliminate the transverse grain boundary, obtain a continuous columnar crystal structure, obtain a higher conductivity and processing performance in the longitudinal direction of the rod and wire blank, and at the same time, reduce the intermediate annealing link in the processing process, thereby reducing energy consumption and shortening the preparation process; and, after the melting treatment of the downward continuous casting process, the purity of the alloy rod can be increased to ≥99.995%. Due to its high purity, the damage of impurities to the directional movement of free electrons is reduced, and the conductivity of the composite material is improved. The present invention adopts a specific solid solution aging process, which can make the silver phase evenly dispersed in the copper matrix, while reducing the Ag solid solubility, generating more precipitated silver phases, reducing the dependence of fiber reinforcement on high Ag alloys, and avoiding the defects of cast drawing. The present invention can make the silver phase form a fiber along the drawing direction through the drawing process, which can not only make the copper matrix and the silver phase closely compounded together, but also significantly improve the conductivity and strength of the composite wire. The results of the examples show that the tensile strength of the copper-silver alloy wire prepared by the present invention is greater than 1 GPa, and the electrical conductivity is greater than 80% IACS. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 : The stress-strain curves of the copper-silver alloy wires (φ0.1 mm) obtained in Example 2 and Comparative Example 1;

[0027] Figure 2 The alloy structure of the copper-silver alloy rod obtained in Examples 1 and 2 (before solution aging treatment);

[0028] Figure 3 The alloy structure of the copper-silver alloy rod after solution aging treatment in Example 1;

[0029] Figure 4 The alloy structure of the copper-silver alloy rod after solution aging treatment in Example 2;

[0030] Figure 5 This is the alloy structure of the copper-silver alloy wire (φ0.1 mm) obtained after recovery annealing in Example 2. DETAILED DESCRIPTION

[0031] The present invention provides a method for preparing an endogenous Ag fiber reinforced Cu-Ag alloy wire material, wherein the endogenous Ag fiber reinforced Cu-Ag alloy wire material comprises an endogenous Ag fiber reinforced Cu-Ag alloy wire material and an endogenous Ag fiber reinforced Cu-Ag alloy fine wire material;

[0032] The preparation method comprises the following steps:

[0033] Step 1: heating and melting copper and silver and then performing vacuum continuous casting to obtain a Cu-Ag alloy rod;

[0034] Step 2: performing solid solution treatment, aging and drawing on the Cu-Ag alloy rod in sequence to obtain an initial Cu-Ag alloy wire reinforced with endogenous Ag fibers;

[0035] Step 3: performing recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire material in step 2 to obtain an endogenous Ag fiber reinforced Cu-Ag alloy wire material;

[0036] Step 4: sequentially subjecting the initial Cu-Ag alloy wire reinforced with endogenous Ag fibers in step 2 to softening annealing, microfilament drawing and recovery annealing to obtain Cu-Ag alloy microfilaments reinforced with endogenous Ag fibers;

[0037] There is no time order restriction for step 3 and step 4;

[0038] The mass fraction of silver in the endogenous Ag fiber reinforced Cu-Ag alloy wire is 4-8%.

[0039] In the present invention, the products prepared in steps 1 to 3 are Cu-Ag alloy wires; the products prepared in steps 1, 2 and 4 are Cu-Ag alloy fine wires, which are described in detail below.

[0040] The present invention heats and melts copper and silver and then performs vacuum continuous casting to obtain a Cu-Ag alloy rod. In the present invention, the purity of the copper is preferably ≥99.99%, and the purity of the silver is preferably ≥99.99%; the ratio of the copper and silver can be calculated according to the mass fraction of copper and silver in the target Cu-Ag alloy wire. In the present invention, the melting temperature of the vacuum continuous casting is preferably 1200-1400°C, more preferably 1250-1350°C, and the melting times of the vacuum continuous casting are preferably 1-3 times. The present invention can purify the alloy rod by melting, thereby reducing the damage of impurities to the directional movement of free electrons and improving the conductivity of the composite material; the pulling speed of the vacuum continuous casting is preferably 50-200mm / min, more preferably 100-150mm / min; the purity of the copper-silver alloy rod is ≥99.995% (i.e., the total content of Cu+Ag), and the oxygen content is below 3ppm. Downward continuous casting is a directional solidification method. Compared with the traditional melt-casting method, it can effectively eliminate the transverse grain boundaries, obtain a continuous columnar crystal structure, and obtain higher electrical conductivity and processing performance in the longitudinal direction of the rod and wire billet. At the same time, it can reduce the intermediate annealing link in the processing process, thereby reducing energy consumption and shortening the preparation process.

[0041] After obtaining the Cu-Ag alloy rod, the present invention sequentially performs solid solution, aging and drawing on the Cu-Ag alloy rod to obtain the initial wire material of the endogenous Ag fiber reinforced Cu-Ag alloy wire. In the present invention, the solid solution temperature is 740-780°C, preferably 750-770°C, and more preferably 760°C, and the solid solution time is 2-4h; water cooling is preferably performed after the solid solution; the aging temperature is 300-500°C, and the aging time is 2-32h, preferably 8-16h; water cooling is preferably performed after the aging; the solid solution and aging are preferably performed in a vacuum furnace, and the vacuum degree of the vacuum furnace is preferably higher than 3.0×10 - 2 Pa. The present invention transforms the dendritic eutectic structure in the cast structure of the copper-silver alloy rod into a granular or strip eutectic structure through solid solution aging treatment, and the silver phase is evenly dispersed in the copper matrix.

[0042] In the present invention, the drawing in step 2 is preferably cold drawing; in the drawing process of step 2, when the diameter of the drawn wire is greater than 0.8 mm, the wire drawing pass deformation rate is 10% to 20%, and the drawing speed is 30 to 70 mm / min, more preferably 40 to 60 mm / min; when the diameter of the drawn wire is less than 0.8 mm, the wire drawing pass deformation rate is 8% to 12%, and the drawing speed is 400 to 800 m / min, more preferably 500 to 700 mm / min; the drawing is preferably carried out using a multi-mode drawing machine. After drawing, the grains in the alloy are elongated and evolved into a fiber form, thereby significantly improving the conductivity and strength of the composite wire.

[0043] After drawing, the present invention performs recovery annealing on the obtained endogenous Ag fiber reinforced Cu-Ag alloy initial wire to obtain an endogenous Ag fiber reinforced Cu-Ag alloy wire. In the present invention, the recovery annealing temperature is preferably 150-200°C, and the annealing speed is preferably 100-200m / min; the diameter of the endogenous Ag fiber reinforced Cu-Ag alloy wire is preferably 0.1-0.3mm.

[0044] In the present invention, when preparing fine wires, after obtaining the endogenous Ag fiber reinforced Cu-Ag alloy initial wire, the present invention sequentially performs softening annealing, fine wire drawing and recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire to obtain endogenous Ag fiber reinforced Cu-Ag alloy fine wires. In the present invention, the softening annealing temperature is preferably 300-500°C, more preferably 350-450°C; the annealing speed is preferably 100-400m / min, more preferably 200-300m / min; the recovery annealing temperature is 150-200°C, and the annealing speed is 100-200m / min.

[0045] In the present invention, the micro-filament drawing is preferably cold drawing; during the micro-filament drawing process, the pass deformation rate of the wire is preferably 6% to 8%, and the drawing speed is preferably 600 to 1000 m / min, more preferably 700 to 900 m / min. The micro-filament drawing is preferably carried out using a multi-mode drawing machine. After the micro-filament drawing treatment, the grains in the alloy are elongated and evolved into a fiber form, thereby significantly improving the conductivity and strength of the composite wire. In the present invention, the temperature of the recovery annealing in step 4 is preferably 150 to 200°C, and the annealing speed is preferably 100 to 200 m / min.

[0046] In the present invention, the diameter of the endogenous Ag fiber reinforced Cu-Ag alloy fine wire is preferably 0.02-0.05 mm.

[0047] The present invention also provides an endogenous Ag fiber reinforced Cu-Ag alloy wire prepared by the preparation method described in the above scheme; the endogenous Ag fiber reinforced Cu-Ag alloy wire comprises a copper matrix and an endogenous Ag fiber reinforcement phase; the endogenous Ag fiber reinforced Cu-Ag alloy wire has a tensile strength greater than 1 GPa and an electrical conductivity greater than 80% IACS.

[0048] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0049] The purity of copper and silver used in the following examples is 99.99%.

[0050] Example 1

[0051] (1) Continuous casting of copper-silver alloy rods:

[0052] Copper and silver were placed in a crucible of a vacuum continuous casting furnace in a ratio of 94% by mass of copper and 6% by mass of silver. The melting temperature was controlled at 1200°C, and a copper-silver alloy rod with a diameter of 6 mm (total copper and silver content of 99.999%, oxygen content of 1.3 ppm) was continuously cast at a pulling speed of 100 mm / min.

[0053] (2) Solution aging treatment of copper-silver alloy rod:

[0054] The copper-silver alloy rod with a diameter of 6 mm was subjected to solution treatment and aging treatment in a vacuum furnace. During the solution treatment and aging treatment, the vacuum degree of the vacuum furnace was higher than 3.0×10 -2 Pa. The solution temperature is 760℃, the solution time is 4 hours, and the solution is cooled by water. The aging temperature is 300℃, the aging time is 16 hours, and the solution is cooled by water. Through this process, the dendritic eutectic structure in the cast structure of the copper-silver alloy rod is transformed into a granular eutectic structure.

[0055] (3) Preparation of copper-silver alloy wire:

[0056] (3.1) Drawing of copper-silver alloy wire:

[0057] The copper-silver alloy rod after solution aging treatment is drawn into a copper-silver alloy wire with a diameter of 0.8 mm by a multi-mode drawing machine, and the drawing speed is 40 m / min. During the drawing process, the drawing pass deformation rate is 15-20%. The copper-silver alloy wire with a diameter of 0.8 mm is drawn into a copper-silver alloy wire with a diameter of 0.1 mm by a multi-mode wire drawing machine, and the drawing speed is 500 m / min. During the drawing process, the drawing pass deformation rate is 8-12%.

[0058] (3.2) Recovery annealing of copper-silver alloy wire:

[0059] The copper-silver alloy wire drawn by a multi-mode wire drawing machine into a diameter of 0.1 mm was subjected to recovery annealing treatment at an annealing temperature of 150° C. and an annealing speed of 200 m / min.

[0060] (4) Preparation of copper-silver alloy microwires:

[0061] (4.1) Softening annealing of copper-silver alloy wire

[0062] The copper-silver alloy wire drawn into a diameter of 0.1 mm by a multi-mode wire drawing machine in step (3.1) is directly subjected to softening annealing treatment at an annealing temperature of 450° C. and an annealing speed of 200 m / min.

[0063] (4.2) Drawing of copper-silver alloy fine wire:

[0064] The copper-silver alloy wire after softening annealing is drawn into a copper-silver alloy wire with a diameter of 0.02 mm by a multi-mode wire drawing machine at a drawing speed of 700 m / min. During the drawing process, the drawing pass deformation rate is 6-8%.

[0065] (4.3) Recovery annealing of copper-silver alloy fine wire:

[0066] The copper-silver alloy fine wire drawn by a multi-mode wire drawing machine into a diameter of 0.02 mm was subjected to recovery annealing treatment at an annealing temperature of 200° C. and an annealing speed of 100 m / min.

[0067] Example 2

[0068] (1) Continuous casting of copper-silver alloy rods:

[0069] Copper and silver were placed in a crucible of a vacuum continuous casting furnace in a ratio of 94% by mass of copper and 6% by mass of silver. The melting temperature was controlled at 1200°C to continuously cast a copper-silver alloy rod with a diameter of 6 mm (the total copper-silver content was 99.999% and the oxygen content was 1.3 ppm) at a pulling speed of 100 mm / min.

[0070] (2) Solution aging treatment of copper-silver alloy rod:

[0071] The copper-silver alloy rod with a diameter of 6 mm was subjected to solution treatment and aging treatment in a vacuum furnace. During the solution treatment and aging treatment, the vacuum degree of the vacuum furnace was higher than 3.0×10 -2 Pa. The solution temperature is 760℃, the solution time is 2 hours, and the water is cooled. The aging temperature is 450℃, the aging time is 16 hours, and the water is cooled. Through this process, the dendritic eutectic structure in the cast structure of the copper-silver alloy rod is transformed into a strip eutectic structure.

[0072] (3) Preparation of copper-silver alloy wire:

[0073] (3.1) Drawing of copper-silver alloy wire:

[0074] The copper-silver alloy rod after solution aging treatment is drawn into a copper-silver alloy wire with a diameter of 0.8 mm by a multi-mode drawing machine, and the drawing speed is 40 m / min. During the drawing process, the drawing pass deformation rate is 15-20%. The copper-silver alloy wire with a diameter of 0.8 mm is drawn into a copper-silver alloy wire with a diameter of 0.1 mm by a multi-mode wire drawing machine, and the drawing speed is 500 m / min. During the drawing process, the drawing pass deformation rate is 8-12%.

[0075] (3.2) Recovery annealing of copper-silver alloy wire:

[0076] The copper-silver alloy wire drawn by a multi-mode wire drawing machine into a diameter of 0.1 mm was subjected to recovery annealing treatment at an annealing temperature of 150° C. and an annealing speed of 200 m / min.

[0077] (4) Preparation of copper-silver alloy microwires:

[0078] (4.1) Softening annealing of copper-silver alloy wire

[0079] The copper-silver alloy wire drawn into a diameter of 0.1 mm by a multi-mode wire drawing machine in step (3.1) is directly subjected to softening annealing treatment at an annealing temperature of 450° C. and an annealing speed of 200 m / min.

[0080] (4.2) Drawing of copper-silver alloy fine wire:

[0081] The copper-silver alloy wire after softening annealing is drawn into a copper-silver alloy wire with a diameter of 0.02 mm by a multi-mode wire drawing machine at a drawing speed of 700 m / min. During the drawing process, the drawing pass deformation rate is 6-8%.

[0082] (4.3) Recovery annealing of copper-silver alloy fine wire:

[0083] The copper-silver alloy fine wire drawn by a multi-mode wire drawing machine into a diameter of 0.02 mm was subjected to recovery annealing treatment at an annealing temperature of 200° C. and an annealing speed of 100 m / min.

[0084] Comparative Example 1

[0085] The copper-silver composite wire is prepared by direct casting drawing method, and the specific steps are as follows:

[0086] (1) Continuous casting of copper-silver alloy rods:

[0087] Copper and silver were placed in a crucible of a vacuum continuous casting furnace in a ratio of 94% by mass of copper and 6% by mass of silver. The melting temperature was controlled at 1200°C, and a copper-silver alloy rod with a diameter of 6 mm was continuously cast at a pulling speed of 100 mm / min.

[0088] (2) Preparation of copper-silver alloy wire:

[0089] The copper-silver alloy rod with a diameter of 6 mm is drawn into a copper-silver alloy wire with a diameter of 0.8 mm by a multi-mode drawing machine, and the drawing speed is 40 m / min. During the drawing process, the deformation rate of each drawing pass is 15-20%. The copper-silver alloy wire with a diameter of 0.8 mm is drawn into a copper-silver alloy wire with a diameter of 0.1 mm by a multi-mode wire drawing machine, and the drawing speed is 500 m / min. During the drawing process, the deformation rate of each drawing pass is 8-12%. The copper-silver alloy wire drawn into a diameter of 0.1 mm by a multi-mode wire drawing machine is subjected to recovery annealing treatment, and the annealing temperature is 150°C and the annealing speed is 200 m / min.

[0090] Performance Testing:

[0091] The performance of the wires prepared in the above-mentioned Example 1, Example 2 and Comparative Example 1 was tested, and the results are shown in Table 1:

[0092] Table 1 Performance test results

[0093]

[0094] In Table 1: The strain (η) calculation formula is as follows: η=ln(A0 / A), where A0 is the initial cross-sectional area of ​​the sample, and A is the final cross-sectional area of ​​the sample after drawing.

[0095] According to the data in Table 1, it can be seen that the copper-silver alloy wire prepared by the present invention has high tensile strength and high electrical conductivity. Compared with Example 2, Comparative Example 1 has the same silver content, but the tensile strength of the obtained copper-silver alloy wire is lower, and the electrical conductivity is also lower.

[0096] Figure 1 The stress-strain curves of the copper-silver alloy wire (φ0.1 mm) obtained in Example 2 and Comparative Example 1 are shown in Table 1. Figure 1 It can be seen that the copper-silver alloy wire prepared in Example 2 has more excellent mechanical properties.

[0097] Figure 2 The alloy structure of the copper-silver alloy rod obtained in Examples 1 and 2 (before solution aging treatment) is as follows: Figure 2 It can be seen that before solution aging treatment, the copper-silver alloy rod has a cast dendritic structure.

[0098] Figure 3 is the alloy structure of the copper-silver alloy rod after solution aging treatment in Example 1, according to Figure 3 It can be seen that after aging treatment at 300 °C, the alloy structure is transformed into a granular eutectic structure.

[0099] Figure 4is the alloy structure of the copper-silver alloy rod after solution aging treatment in Example 2, according to Figure 4 It can be seen that after aging treatment at 450℃, the alloy structure is transformed into a strip eutectic structure.

[0100] Figure 5 The alloy structure of the copper-silver alloy wire (φ0.1 mm) obtained after recovery annealing in Example 2 is shown in FIG. Figure 5 It can be seen that after drawing, the silver phase inside the alloy is transformed into a fibrous form.

[0101] It can be seen from the above embodiments that the present invention prepares a Cu-Ag alloy wire with uniformly dispersed silver phase through solid solution aging treatment, and through subsequent drawing treatment, the copper matrix and the silver phase evolve into a fiber form, so that the alloy becomes a fiber-reinforced two-phase composite material. The preparation method includes continuous casting of alloy rods, solid solution aging treatment, drawing, intermediate heat treatment and drawing. The Cu-Ag alloy wire prepared by this method reduces the Ag content while avoiding problems such as uneven organization, and significantly improves the conductivity and mechanical properties of the composite wire. Its tensile strength is not less than 1GPa, and its conductivity is not less than 80%IACS.

[0102] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A method for preparing a Cu-Ag alloy wire reinforced with endogenous Ag fibers, characterized in that: The endogenous Ag fiber reinforced Cu-Ag alloy wire material includes endogenous Ag fiber reinforced Cu-Ag alloy wire material and endogenous Ag fiber reinforced Cu-Ag alloy fine wire material; The preparation method comprises the following steps: Step 1: heating and melting copper and silver and then performing vacuum continuous casting to obtain a Cu-Ag alloy rod; Step 2: performing solid solution treatment, aging and drawing on the Cu-Ag alloy rod in sequence to obtain an initial Cu-Ag alloy wire reinforced with endogenous Ag fibers; Step 3: performing recovery annealing on the endogenous Ag fiber reinforced Cu-Ag alloy initial wire material in step 2 to obtain an endogenous Ag fiber reinforced Cu-Ag alloy wire material; Step 4: sequentially subjecting the endogenous Ag fiber reinforced Cu-Ag alloy initial wire material in step 2 to softening annealing, microfilament drawing and recovery annealing to obtain endogenous Ag fiber reinforced Cu-Ag alloy microfilament material; There is no time order restriction for step 3 and step 4; The mass fraction of silver in the endogenous Ag fiber reinforced Cu-Ag alloy wire is 4-8%; The solution temperature in step 2 is 740°C to 780°C, the time is 2 to 4 hours, and the cooling method is water cooling; The softening annealing temperature in step 4 is 300-500° C., and the annealing speed is 100-400 m / min; the recovery annealing temperature in steps 3 and 4 is 150-200° C., and the annealing speed is 100-200 m / min.

2. The preparation method according to claim 1, characterized in that: The copper-silver alloy rod in step 1 has a purity of >99.995% and an oxygen content of <3ppm.

3. The preparation method according to claim 1, characterized in that: The aging temperature in step 2 is 300-500° C., the time is 2-32 hours, and the cooling method is water cooling.

4. The preparation method according to claim 1, characterized in that: The diameter of the endogenous Ag fiber reinforced Cu-Ag alloy wire is 0.1-0.3 mm; the diameter of the endogenous Ag fiber reinforced Cu-Ag alloy fine wire is 0.02-0.05 mm.

5. The preparation method according to claim 1, characterized in that: The drawing in step 2 is cold drawing; during the drawing process in step 2, when the diameter of the drawn wire is greater than 0.8 mm, the deformation rate of the drawing pass is 10% to 20%, and the drawing speed is 30 to 70 m / min; when the diameter of the drawn wire is less than 0.8 mm, the deformation rate of the drawing pass is 8% to 12%, and the drawing speed is 400 to 800 m / min.

6. The preparation method according to claim 1, characterized in that: The microfilament drawing in step 4 is cold drawing, the deformation rate of the microfilament drawing is 6% to 8%, and the drawing speed is 600 to 1000 m / min.

7. The Cu-Ag alloy wire reinforced with endogenous Ag fiber prepared by the preparation method according to any one of claims 1 to 6.

8. The endogenous Ag fiber reinforced Cu-Ag alloy wire according to claim 7, characterized in that: The tensile strength of the endogenous Ag fiber reinforced Cu-Ag alloy wire is greater than 1 GPa, and the electrical conductivity is greater than 80% IACS.

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