CN104889193A - Cu-Nb composite wire comprehensive performance improvement preparation method - Google Patents

Abstract

The invention relates to a preparation method for improving the comprehensive performance of Cu-Nb composite wires, which comprises the following steps: (1) A single Nb core Cu- Nb composite wire; (2) Single Nb core Cu-Nb composite wire is divided into 55 equal parts and then assembled with a pure Cu sleeve to obtain 55Nb core Cu-Nb composite wire; (3) 55Nb core Cu-Nb composite wire Repeat step (2) for wire to obtain 55 ² Nb core Cu-Nb composite wire; (4) 55 ² Nb core Cu-Nb composite wire repeat step (3) to obtain 55 ³ Nb core Cu-Nb composite wire; (5) 55 ³ The Nb core Cu-Nb composite wire is divided into 85 equal parts and assembled with 1 pure Cu sleeve and 1 pure Cu rod to obtain 85×55 ³ Nb core Cu-Nb composite wire; (6) 85×55 ³ Nb core Cu-Nb composite wires Repeat step (5) to obtain 85 ² ×55 ³ Nb core Cu-Nb composite wires. The Cu-Nb composite wire prepared by this method fully exerts the influence of pure Cu's high conductivity and multi-scale structure on performance, and at the same time weakens the decrease in conductivity caused by work hardening, so that the Cu-Nb composite wire has higher conductivity and strength. Well combined.

Description

A preparation method for improving the comprehensive performance of Cu-Nb composite wire

technical field

The invention relates to a preparation method for improving the comprehensive performance of Cu-Nb composite wire.

Background technique

The Cu-Nb composite wire prepared by cluster drawing has broad application prospects in the fields of strong magnetic field construction, medicine and railway transportation because of its high strength and excellent electrical conductivity. However, there is a contradictory relationship between the strength and conductivity of Cu-Nb composite wires. Increasing the strength of the material is often accompanied by a decrease in conductivity. This contradictory relationship has become an important factor limiting the application of Cu-Nb composite wires.

The high strength and excellent electrical conductivity of Cu-Nb microcomposite wires are closely related to the multi-scale structural properties of the nanofiber composite structure and matrix formed after large deformation drawing. At present, researchers around the world have invested a lot of manpower and material resources in experimental research and actual production, striving to optimize the conductivity and strength of composite wires to meet actual production needs. How to further optimize the matching of strength and conductivity of Cu-Nb composite wires, so as to obtain excellent conductivity without significantly reducing the strength of the wires, has become a key problem that needs to be solved urgently for this type of composite wires.

Contents of the invention

The technical problem to be solved by the present invention is to provide a preparation method for improving the comprehensive performance of Cu-Nb composite wire, which not only has a simple preparation process, but also realizes reasonable optimization of the performance of the Cu-Nb composite material.

In order to solve the above technical problems, the technical solution of the present invention is: a preparation method for improving the comprehensive performance of Cu-Nb composite wire, comprising the following steps:

(1) Firstly select a pure Cu sleeve and a pure Nb rod for assembly, set the pure Cu sleeve outside the pure Nb rod, and place the pure Nb rod at the center of the pure Cu sleeve , followed by vacuum sealing, hot extrusion, and multi-pass cold drawing to obtain single Nb core Cu-Nb composite wire;

(2) Divide the single Nb core Cu-Nb composite wire obtained in step (1) into 55 equal parts along its length direction, and continue to select a pure Cu sleeve for assembly, and set the pure Cu sleeve at 55 equal parts. In addition to the single Nb core Cu-Nb composite wire, the 55 equal parts of the single Nb core Cu-Nb composite wire are arranged in a columnar body at the center of the pure Cu sleeve, and another pure Cu rod is used to fill the pure Cu sleeve with 55 etc. After being placed in the gap of a single Nb core Cu-Nb composite wire rod, vacuum sealing and welding, hot extrusion processes are carried out successively, and then multi-pass cold drawing is carried out to obtain a 55Nb core Cu-Nb composite wire rod;

(3) repeating the process in step (2) for the 55Nb core Cu-Nb composite wire obtained in step (2) to obtain a 55 ² Nb core Cu-Nb composite wire;

(4) repeating the process in step (3) for the 55 ² Nb core Cu-Nb composite wire obtained in step (3) to obtain a 55 ³ Nb core Cu-Nb composite wire;

(5) Continue to divide the 55 ³ Nb core Cu-Nb composite wire obtained in step (4) into 85 equal parts along its length direction, and continue to select one pure Cu sleeve and one pure Cu rod for assembly , put the pure Cu rod at the center of the pure Cu tube sleeve, arrange 85 equal parts of 55 ³ Nb core Cu-Nb composite wires evenly around the pure Cu rod to form a column, and set the pure Cu tube sleeve on the pure Cu rod, 85 equal parts of 55 ³ Nb core Cu-Nb composite wire, and another pure Cu rod was taken to fill the gap between pure Cu sleeve and pure Cu rod, 55 ³ Nb core Cu-Nb composite wire, Carry out vacuum sealing and welding, hot extrusion in sequence, and then perform multi-pass cold drawing to obtain 85×55 ³ Nb core Cu-Nb composite wire;

(6) Repeat the process in step (5) for the 85×55 ³ Nb core Cu-Nb composite wire obtained in step (5) to obtain an 85 ² ×55 ³ Nb core Cu-Nb composite wire.

Further, the welding vacuum degree of the vacuum sealing welding is greater than 5×10 ^-3 Pa, the hot extrusion temperature is 550~650°C, the drawing speed is 15mm/s, the deformation of each pass is controlled below 20%, and the drawing The annealing temperature of the annealing process introduced in the drawing process is 700°C, and the annealing time is 40-120min.

Further, the weight percentage of the Cu element in the selected pure Cu tube sleeve and pure Cu rod is greater than 99.9%, the weight percentage of the O element is less than or equal to 0.003%, and the weight percentage of the impurity is less than or equal to 0.05%; the weight percentage of Nb element in the selected pure Nb rod is 99.9%, and the weight percentage of impurities is less than or equal to 0.05%.

Further, in step (1), before assembling the pure Cu sleeve and the pure Nb rod, the pure Cu sleeve and the pure Nb rod are polished, pickled, and straightened to clean their surfaces; In step (2), before assembling the pure Cu sleeve and 55 equal parts of the single Nb core Cu-Nb composite wire, the pure Cu sleeve and the single Nb core Cu-Nb composite wire were firstly polished, pickled, Straightening step, cleaning its surface; in step (5), before assembling the pure Cu sleeve, pure Cu rod and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire, first clean the pure Cu sleeve, Pure Cu rods and 85 equal parts of 55 ³ Nb core Cu-Nb composite wires were polished, pickled, and straightened to clean their surfaces.

Further, in step (1), the pure Cu sleeve and the pure Nb rod have the same length; in step (2), the pure Cu sleeve and 55 equal parts single Nb core Cu-Nb composite wire are equal in length; in step (5), the lengths of the pure Cu sleeve, pure Cu rod and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire are equal.

Compared with the prior art, the present invention has the following beneficial effects: the Cu-Nb composite wire prepared by the method fully exerts the influence of pure Cu's high conductivity and multi-scale structure on performance, and at the same time weakens the decline in conductivity caused by work hardening, The Cu-Nb composite wire has a good combination of high conductivity and strength.

The present invention will be described in further detail below in conjunction with the accompanying drawings and specific embodiments.

Description of drawings

Fig. 1 is a schematic diagram of the cross-sectional structure of an 85×55 ³ Nb core Cu-Nb composite wire according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the cross-sectional structure of an 85 ² × 55 ³ Nb core Cu-Nb composite wire according to an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of an embodiment of the present invention.

In the picture: 1-pure Cu sleeve, 2-55 ³ Nb core Cu-Nb composite wire, 3-85×55 ³ Nb core Cu-Nb composite wire, 4-center pure Cu rod, 5-gap pure Cu rod material.

Detailed ways

In the present invention, as shown in Figures 1 to 3, a preparation method for improving the comprehensive performance of Cu-Nb composite wire comprises the following steps:

(1) Firstly select a pure Cu sleeve and a pure Nb rod for assembly, set the pure Cu sleeve outside the pure Nb rod, and place the pure Nb rod at the center of the pure Cu sleeve , followed by vacuum sealing, hot extrusion, and multi-pass cold drawing to obtain a single Nb core Cu-Nb composite wire;

(2) Divide the single Nb core Cu-Nb composite wire obtained in step (1) into 55 equal parts along its length direction, and continue to select a pure Cu sleeve for assembly, and set the pure Cu sleeve at 55 equal parts. In addition to the single Nb core Cu-Nb composite wire, the 55 equal parts of the single Nb core Cu-Nb composite wire are arranged in a columnar body at the center of the pure Cu sleeve, and the columnar body is in the shape of a regular hexagonal honeycomb as a whole. Take another gap pure Cu rod to fill the gap between the pure Cu sleeve and 55 equal parts single Nb core Cu-Nb composite wire, the gap pure Cu rod is pure Cu rod, and it is vacuum sealed and welded, heat Extrusion process, and then multi-pass cold drawing to obtain 55Nb core Cu-Nb composite wire;

(3) repeating the process in step (2) for the 55Nb core Cu-Nb composite wire obtained in step (2) to obtain a 55 ² Nb core Cu-Nb composite wire;

(4) repeating the process in step (3) for the 55 ² Nb core Cu-Nb composite wire obtained in step (3) to obtain a 55 ³ Nb core Cu-Nb composite wire;

(5) Continue to divide the 55 ³ Nb core Cu-Nb composite wire obtained in step (4) into 85 equal parts along its length direction, and continue to select one pure Cu sleeve and one pure Cu rod for assembly , put the pure Cu rod at the center of the pure Cu tube sleeve, arrange 85 equal parts of 55 ³ Nb core Cu-Nb composite wires evenly on the periphery of the pure Cu rod to form a columnar body, and the columnar body is in the shape of a positive hexagonal body as a whole. Polygonal honeycomb shape, the pure Cu sleeve is set outside the pure Cu rod and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire, and another gap is taken from the pure Cu rod to fill the pure Cu sleeve and the pure Cu rod , 55 ³ Nb core Cu-Nb composite wire in the gap, the pure Cu rod in the gap is a pure Cu rod, which is subjected to vacuum sealing welding, hot extrusion process, and then multi-pass cold drawing to obtain 85 ×55 ³ Nb core Cu-Nb composite wire;

(6) Repeat the process in step (5) for the 85×55 ³ Nb core Cu-Nb composite wire obtained in step (5) to obtain an 85 ² ×55 ³ Nb core Cu-Nb composite wire.

In the present invention, the welding vacuum degree of the vacuum sealing welding is greater than 5×10 ^-3 Pa, the hot extrusion temperature is 550~650°C, the drawing rate is 15mm/s, and the deformation per pass is controlled below 20% , the annealing temperature of the annealing process introduced in the drawing process is 700°C, and the annealing time is 40~120min.

In the present invention, the percentage by weight of the Cu element in the selected pure Cu pipe sleeve and pure Cu rod is greater than 99.9%, the percentage by weight of the O element is less than or equal to 0.003%, and the weight percentage of the impurity The percentage is less than or equal to 0.05%; the weight percentage of Nb element in the selected pure Nb rod is 99.9%, and the weight percentage of impurities is less than or equal to 0.05%.

In the present invention, in step (1), before assembling the pure Cu sleeve and the pure Nb rod, the pure Cu sleeve and the pure Nb rod are first polished, pickled, and straightened to clean them. surface; in step (2), before assembling the pure Cu sleeve and 55 equal parts single Nb core Cu-Nb composite wire, the pure Cu sleeve and single Nb core Cu-Nb composite wire were polished, Washing and straightening steps to clean its surface; in step (5), before assembling pure Cu tube sleeves, pure Cu rods and 85 equal parts of 55 ⁿ Nb core Cu-Nb composite wires, first clean the pure Cu tube sleeve, pure Cu rod and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire are subjected to grinding, pickling, and straightening steps to clean the surface, that is, before each assembly, grinding, pickling is required , Straightening step, cleaning the surface of the material.

In the present invention, in step (1), the pure Cu sleeve and the pure Nb rod have the same length; in step (2), the pure Cu sleeve and 55 equal parts single Nb core Cu-Nb The lengths of the composite wires are equal; in step (5), the lengths of the pure Cu sleeves, pure Cu rods, and 85 equal parts of 55 ³ Nb core Cu-Nb composite wires are equal, that is, before each assembly , the lengths of the assembled components are all equal.

In the present invention, a pure Nb rod is placed in the center of a pure Cu tube sleeve, and electron beam vacuum sealing welding is carried out, and the vacuum degree of the welding chamber is above 5×10 ^-3 Pa; followed by hot extrusion along the DD direction , in the drawings, the direction DD represents the drawing or extrusion direction, the direction DD has the uniqueness of the direction, the direction DD * represents the opposite direction of the drawing or extrusion direction DD, and the direction TD represents the transverse or hoop direction of the material; Extrusion temperature is within 550~650°C; finally, multi-pass cold drawing along the DD direction, each drawing deformation is about 20%, the speed is 15mm/s, and the cross-section is positive six for the last drawing. Hexagonal mould, the cross-section of single Nb core Cu-Nb composite wire obtained is a regular hexagon, with a side length of 3.20mm; according to the above-mentioned process, the recirculation is carried out ³ times, and Cu-Nb composite wire containing 553 Nb cores can be obtained. That is 55 ³ Nb core Cu-Nb composite wires; take the above-mentioned 85 above-mentioned 55 ³ Nb core Cu-Nb composite wires, 1 pure Cu tube sleeve and 1 pure Cu rod, and then pack and assemble, so that the pure Cu The bar is in the center, and electron beam vacuum sealing welding is carried out, and the vacuum degree of the welding chamber is above 5×10 ^-3 Pa; then hot extrusion is carried out along the DD direction, and the hot extrusion temperature is within 550~650°C; finally along Multi-pass cold drawing in the DD direction, the amount of drawing deformation in each pass is about 20%, and the speed is 15mm/s. In the last drawing, a die with a regular hexagonal cross-section is used to obtain 85×55 ³ Nb core Cu- The cross-section of the Nb composite wire is a regular hexagon; the above process is repeated once, and finally a Cu-Nb composite wire with 85 ² ×55 ³ Nb core is obtained.

When the diameter of the pure Cu rod is 12.0 mm, the Nb content inside the Cu-Nb composite wire with 85 ² × 55 ³ Nb core is 28.4%, and the width of a single Nb core in the 85 ² × 55 ³ Nb core reaches 78 nm. The tensile strength reaches 860 Mpa, and the electrical conductivity is 73% IACS; when the diameter of the pure Cu rod is 18.0 mm, the internal Nb content of the 85 ² × 55 ³ Nb composite wire is 24.2%, and the 85 ² × 55 ³ Nb The width of a single Nb core in the core reaches 62 nm, the tensile strength reaches 920 Mpa, and the conductivity is 80% IACS.

It can be seen from the above-mentioned technical scheme and performance that the preparation method provided by the present invention ensures that the Nb phase content and size are ensured during subsequent processing by adding additional central pure Cu rods in subsequent assembly and increasing the number of composite material assemblies. At the same level as the existing research reports, the conductivity of the material does not decrease with work hardening, and even increases, while ensuring a high strength of the material, thereby alleviating the contradiction between strength and conductivity, and realizing the Cu- Rational optimization of properties of Nb composites.

The above descriptions are only preferred embodiments of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention shall fall within the scope of the present invention.

Claims (5)

1. a preparation method for improving the comprehensive performance of Cu-Nb composite wire rod, is characterized in that, comprises the following steps: (1) Firstly select a pure Cu sleeve and a pure Nb rod for assembly, set the pure Cu sleeve outside the pure Nb rod, and place the pure Nb rod at the center of the pure Cu sleeve , followed by vacuum sealing, hot extrusion, and multi-pass cold drawing to obtain single Nb core Cu-Nb composite wire; (2) Divide the single Nb core Cu-Nb composite wire obtained in step (1) into 55 equal parts along its length direction, and continue to select a pure Cu sleeve for assembly, and set the pure Cu sleeve at 55 equal parts. In addition to the single Nb core Cu-Nb composite wire, the 55 equal parts of the single Nb core Cu-Nb composite wire are arranged in a column at the center of the pure Cu sleeve, and another pure Cu rod is filled between the pure Cu sleeve and 55 After equalizing the single Nb core Cu-Nb composite wire in the gap, it is followed by vacuum sealing and welding, hot extrusion process, and then multi-pass cold drawing to obtain 55Nb core Cu-Nb composite wire; (3) repeating the process in step (2) for the 55Nb core Cu-Nb composite wire obtained in step (2) to obtain a 55 ² Nb core Cu-Nb composite wire; (4) repeating the process in step (3) for the 55 ² Nb core Cu-Nb composite wire obtained in step (3) to obtain a 55 ³ Nb core Cu-Nb composite wire; (5) Continue to divide the 55 ³ Nb core Cu-Nb composite wire obtained in step (4) into 85 equal parts along its length direction, and continue to select one pure Cu sleeve and one pure Cu rod for assembly , put the pure Cu rod at the center of the pure Cu tube sleeve, arrange 85 equal parts of 55 ³ Nb core Cu-Nb composite wires evenly around the pure Cu rod to form a column, and set the pure Cu tube sleeve on the pure Cu rod, 85 equal parts of 55 ³ Nb core Cu-Nb composite wire, and another pure Cu rod was filled in the gap between pure Cu sleeve and pure Cu rod, 55 ³ Nb core Cu-Nb composite wire , followed by vacuum sealing, hot extrusion, and multi-pass cold drawing to obtain 85×55 ³ Nb core Cu-Nb composite wire; (6) Repeat the process in step (5) for the 85×55 ³ Nb core Cu-Nb composite wire obtained in step (5) to obtain an 85 ² ×55 ³ Nb core Cu-Nb composite wire. 2. A preparation method for improving the comprehensive performance of Cu-Nb composite wire according to claim 1, characterized in that: the welding vacuum degree of the vacuum sealing welding is greater than 5 × 10 ^-3 Pa, and the hot extrusion temperature The temperature is 550~650℃, the drawing rate is 15mm/s, the deformation of each pass is controlled below 20%, the annealing temperature of the annealing process introduced in the drawing process is 700℃, and the annealing time is 40~120min. 3. a kind of preparation method that is used to improve the comprehensive performance of Cu-Nb composite wire rod according to claim 2, is characterized in that: the percentage by weight that the Cu element in the selected pure Cu sleeve and pure Cu rod occupies More than 99.9%, the weight percentage of O element is less than or equal to 0.003%, and the weight percentage of impurities is less than or equal to 0.05%; the weight percentage of Nb element in the selected pure Nb rod is 99.9% , the percentage by weight of impurities is less than or equal to 0.05%. 4. A preparation method for improving the comprehensive performance of Cu-Nb composite wire according to claim 3, characterized in that: in step (1), before assembling the pure Cu sleeve and the pure Nb rod , the pure Cu sleeve and pure Nb rod are first polished, pickled, and straightened to clean the surface; in step (2), the pure Cu sleeve and 55 equal parts of single Nb core Cu-Nb composite Before the wires are assembled, the pure Cu sleeve and the single Nb core Cu-Nb composite wire are firstly polished, pickled, and straightened to clean the surface; in step (5), the pure Cu sleeve, pure Cu Before the bar and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire are assembled, the pure Cu sleeve, pure Cu rod and 85 equal parts of 55 ³ Nb core Cu-Nb composite wire are polished, pickled and straightened. Step straight to clean its surface. 5. A preparation method for improving the comprehensive performance of Cu-Nb composite wire according to claim 4, characterized in that: in step (1), the lengths of the pure Cu sleeve and the pure Nb rod are equal ; In step (2), the lengths of the pure Cu sleeve and 55 equal parts single Nb core Cu-Nb composite wire are equal; in step (5), the pure Cu sleeve, pure Cu rod and 85 Equal parts of 55 ³ Nb core Cu-Nb composite wires are equal in length.