CN1329538C - Method for making enforced double-axis woven Ag/AgMg composite base band - Google Patents

Abstract

The invention belongs to the field of high-temperature superconducting reinforced toughness materials. So far, no single stable {110}<110> biaxial texture has been formed on the surface of Ag alloy or Ag-Cu composite substrate strengthened substrate. The steps of this method are: melting Mg powder and Ag powder under the protection of argon to make Ag _0.90 Mg _0.10 or Ag _0.99 Mg _0.01 initial ingot and then rolling to 1-4mm thick; according to Ag foil-Cu foil-AgMg initial ingot -Cu foil-Ag foil or Ag foil-Cu foil-AgMg multi-layer ingot obtained by sequential cold pressing of the initial ingot, with a thickness of 5mm~13mm, of which the thickness of Ag foil is 3mm~8.5mm, and the thickness of Cu foil is 30μm~40μm; 800 ℃～850℃vacuum annealing for 3～5 hours; after annealing, cold rolling, the deformation of each pass is 10%～15%, the total deformation is more than 95%, and the base band of 300μm～100μm is obtained; 800℃～850℃vacuum or argon Annealing under air condition for 3 to 5 hours, and then oxygen annealing at 850°C to 900°C for 3 to 5 hours to obtain the final product. The composite base tape of the present invention has strong mechanical strength, and at the same time, the Ag surface obtains a {110}<110> texture, and can be used as a base tape for depositing a YBa ₂ Cu ₃ O _7-δ high temperature superconducting film or a Bi tie tape material sheath Material.

Description

Preparation Method of Strengthened Biaxial Texture Ag/AgMg Composite Baseband

technical field

The invention relates to a method for preparing a reinforced Ag-based composite substrate, and belongs to the technical field of preparation of high-temperature superconducting reinforced toughness materials.

Background technique

Due to the advantages of the material itself, that is, high irreversible line, low AC loss, and potential price advantage, the second-generation superconducting materials have attracted the attention of domestic and foreign governments and scientific research institutes in recent years, and have achieved considerable development. The breakthroughs in the performance and price of the wire strip will be transformed into the advantages of industrial production in the near future, showing its strong commercial value; It has been initially applied in some countries, and it is a high-temperature superconducting material that can be applied in a short period of time. Silver is the only base metal that does not require an isolation layer when making superconducting materials, and the use of this material can simplify the process. However, the mechanical strength of Ag is relatively poor, so if its mechanical strength can be improved by compounding in practical applications, it can be used on the composite substrate to directly prepare high-performance high-temperature superconducting films or as Bi-2223PIT strips Packaging materials, thus promoting the process of industrialization.

At present, research groups at home and abroad are conducting research on coating high-temperature superconducting films on composite substrates. Some Ag alloys or Ag-Cu composite substrates have been studied for biaxially textured coated conductors, but on the surface of these strengthened substrates No single stable {110}<110> biaxial texture is formed, which limits the direct deposition of YBCO superconducting thin films on the substrate. Therefore, how to control the texture of the composite silver-based base tape while having high mechanical strength is the key to the practical application of the silver-based composite base tape to prepare YBCO superconducting films.

Contents of the invention

The composite base tape obtained by the present invention has strong mechanical strength, and at the same time, the Ag surface obtains a {110}<110> texture, and can be used as a base tape or a Bi-based tape for depositing YBa ₂ Cu ₃ O _7-δ high-temperature superconducting films Wrapping material.

The present invention provides a kind of preparation method of reinforced biaxial textured Ag-based composite base tape, it is characterized in that, it comprises the following steps:

(1) Mg powder with a purity of more than 99.95wt% and Ag powder with a purity of more than 99.95wt% are melted under the condition of argon protection to make an initial ingot of Ag _0.90 Mg _0.10 or Ag _0.99 Mg _0.01 , and the initial ingot Rolled to 1-4mm thick;

(2) Cold pressing in the order of Ag foil-Cu foil-AgMg initial ingot-Cu foil-Ag foil to obtain multi-layer ingots, or cold pressing in the order of Ag foil-Cu foil-AgMg initial ingots to obtain multi-layer ingots Ingot; the thickness of the multi-layer ingot is 5mm-13mm, the purity of Ag foil is above 99.9wt%, the thickness is 3mm-8.5mm, the purity of Cu foil is above 99.9wt%, and the thickness is 30μm-40μm;

(3) Vacuum annealing the above-mentioned multilayer ingot at 800° C. to 850° C. for 3 to 5 hours;

(4) cold-rolling the annealed multi-layer ingot, with a pass deformation of 10% to 15%, and a total deformation of more than 95%, to obtain a base strip with a thickness of 300 μm to 100 μm;

(5) The obtained base tape is annealed at 800° C.-850° C. for 3-5 hours in vacuum or under argon protection, and then at 850° C.-900° C. for 3-5 hours in oxygen to obtain the final product.

The technical core of the present invention is: use Cu foil as an effective method to connect the outer layer and the core layer respectively, wherein the outer layer is an Ag layer, the core layer is an AgMg alloy layer, and the Cu foil ensures the gap between the core layer and the outer layer. There is no splitting between the layers; the hardness of the base band has been significantly improved through the dispersion strengthening of MgO in the base band; the Ag coating layer of the Ag/AgMg composite base band has {110}<011> orientation.

The key to this technology is to use the pure Ag outer layer to avoid the reaction between the substrate and the YBCO film, and at the same time have the role of the epitaxial substrate layer, and play the role of the core layer with high mechanical strength. This technology will expand the scope of application of Ag as a substrate material in the field of high-temperature superconductivity.

Therefore, the silver-based composite base tape with {110}<110> biaxial texture and high mechanical strength can be prepared by the above process.

Description of drawings

Fig. 1: Composite baseband silver baseband section SEM (a) in embodiment 1, the texture orientation distribution function (ODF) sectional view ( ₂ =0° section) (b) of the texture orientation distribution function (ODF) of baseband surface (b), final baseband (111) surface pole figure (c);

Fig. 2: SEM of the cross-section of the composite baseband silver baseband in Example 2;

Fig. 3: SEM of the cross-section of the composite baseband silver baseband in Example 3;

Figure 4: SEM of the cross-section of the composite baseband silver baseband in Example 4.

Detailed ways

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

Example 1. The initial ingot of 4mm Ag _0.90 Mg _0.10 , 8.5cm thick Ag foil with a purity of 99.95wt%, and 30μm thick Cu foil with a purity of 99.99wt% were arranged in the order of Ag-Cu-AgMg to obtain a multilayer structure, the above-mentioned multi-layer ingot was vacuum annealed at 800°C for 5 hours to obtain a 13mm multi-layer ingot; the multi-layer ingot was cold-rolled, with a deformation of 10-15% per pass, and a total deformation of more than 95%, to obtain 100 μm thick base tape. Then the base tape is vacuum annealed at 800°C for 5 hours, and then oxygen annealed at 880°C for 4 hours to obtain the final product. The cross-sectional SEM of the composite base tape (Figure 1a) shows that the Ag layer and the AgMg layer have good bonding. In Fig. 1b, the recrystallization texture orientation distribution function (ODF) cross-sectional view ( ₂ =0° cross-section) intensity concentration distribution area indicates that the base band has formed a {110}<011> texture, and the pole figure FWHM of the (111) plane is 25° (Fig. 1c). The test result of microhardness (FM-700 produced by Future-tech Company) shows that the dimensional microhardness value of the substrate is 209kgmm ^-2 which is 4 times that of pure Ag.

Example 2. The initial ingot of 4mm Ag _0.90 Mg _0.10 , 8.5cm thick Ag foil with a purity of 99.95wt%, and 40μm thick Cu foil with a purity of 99.99wt% were arranged in the order of Ag-Cu-AgMg to obtain a multilayer structure, the above-mentioned multi-layer ingot was vacuum annealed at 850°C for 3 hours to obtain a 13mm multi-layer ingot; the multi-layer ingot was cold-rolled, with a deformation of 10-15% per pass, and a total deformation of more than 95%, to obtain 300μm thick base tape. Then the base tape is vacuum annealed at 850°C for 3 hours, and then oxygen annealed at 880°C for 4 hours to obtain the final product. The base tape formed a {110}<011> texture, and the Vickers microhardness value reached 158kgmm ^-2 ; the cross-sectional SEM of the composite base tape (Figure 2) showed that the Ag layer and the AgMg layer had good bonding.

Example 3. The Ag _0.99 Mg _0.01 initial ingot of 1mm, 3.5cm thick Ag foil with a purity of 99.95wt%, 30μm thick Cu foil with a purity of 99.99wt%, according to the Ag foil-Cu foil-AgMg initial ingot Arrange in order to obtain multi-layer ingots, and vacuum anneal the above-mentioned multi-layer ingots at 850°C for 4 hours to obtain 5mm multi-layer ingots; cold-roll the multi-layer ingots, the deformation of each pass is 10-15%, and the total deformation The amount is greater than 95%, and a base tape with a thickness of 100 μm is obtained. The base tape is then vacuum annealed at 800°C for 4 hours, and then oxygen annealed at 900°C for 3 hours to obtain the final product. The base tape formed a {110}<011> texture, and the Vickers microhardness value reached 100kgmm ^-2 ; the cross-sectional SEM of the composite base tape (Figure 3) showed that the Ag layer and the AgMg layer had good bonding.

Example 4. 3mm Ag _0.99 Mg _0.01 initial ingot, 3cm thick Ag foil with a purity of 99.95wt%, 30μm thick Cu foil with a purity of 99.99wt%, according to Ag foil-Cu foil-AgMg initial ingot-Cu Foil-Ag foils are arranged in order to obtain a multi-layer ingot, and the above-mentioned multi-layer ingot is vacuum annealed at 800°C for 4 hours to obtain a 9mm multi-layer ingot; the multi-layer ingot is cold-rolled, and the pass deformation is 10-15 %, the total deformation is greater than 95%, and a base tape with a thickness of 120 μm is obtained. Then the base tape was annealed in ammonia gas at 800°C for 4 hours, and then in oxygen at 850°C for 5 hours to obtain the final product. The base tape formed a {110}<011> texture, and the Vickers microhardness value reached 130kgmm ^-2 ; the cross-sectional SEM of the composite base tape (Figure 4) showed that the Ag layer and the AgMg layer had good bonding.

Claims (1)

1, a kind of preparation method of strengthening biaxial texture Ag/AgMg composite substrate, is characterized in that, it comprises the following steps: (1) Mg powder with a purity of more than 99.95wt% and Ag powder with a purity of more than 99.95wt% are melted under the condition of argon protection to make an initial ingot of Ag _0.90 Mg _0.10 or Ag _0.99 Mg _0.01 , and the initial ingot Rolled to 1-4mm thick; (2) Cold pressing in the order of Ag foil-Cu foil-AgMg initial ingot-Cu foil-Ag foil to obtain multi-layer ingots, or cold pressing in the order of Ag foil-Cu foil-AgMg initial ingots to obtain multi-layer ingots Ingot; the thickness of the multi-layer ingot is 5mm-13mm, the purity of Ag foil is above 99.9wt%, the thickness is 3mm-8.5mm, the purity of Cu foil is above 99.9wt%, and the thickness is 30μm-40μm; (3) Vacuum annealing the above-mentioned multilayer ingot at 800° C. to 850° C. for 3 to 5 hours; (4) cold-rolling the annealed multi-layer ingot, with a pass deformation of 10% to 15%, and a total deformation of more than 95%, to obtain a base strip with a thickness of 300 μm to 100 μm; (5) The obtained base tape is annealed at 800° C.-850° C. for 3-5 hours in vacuum or under argon protection, and then at 850° C.-900° C. for 3-5 hours in oxygen to obtain the final product.

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