Nb3Sn superconducting wire preparation method based on 3D printing

Abstract

The invention discloses a preparation method of a Ni3Sn superconducting wire based on 3D printing. The preparation method comprises the following steps: depositing a reticular niobium film on the surface of a tin-titanium alloy rod through 3D printing to obtain a tin-titanium-niobium alloy rod; drilling a hole in the center of the tin-titanium-niobium alloy rod, and inserting a tin-silver alloy rod to obtain the tin-titanium-niobium-silver alloy rod; the tin-titanium-niobium-silver alloy bar is put into the Ni3Sn-copper-niobium composite tube, and then an internal tin method Ni3Sn sub-component is obtained; sequentially putting the internal tin method Ni3Sn subcomponents into the tantalum tube and the oxygen-free copper tube to obtain an internal tin method Ni3Sn blank; and stretching the inner tin method Ni3Sn blank to obtain the Ni3Sn superconducting wire. Due to the existence of the silver element, uniform diffusion of the tin element in the heat treatment process is facilitated, the netted niobium film is deposited on the surface of the tin-titanium alloy rod through 3D printing, the precision and quality of the niobium film are guaranteed, more high-quality Ni3Sn crystal grains can be generated in the heat treatment process of the wire, and the performance of the Ni3Sn wire prepared through the internal tin method is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of superconducting wires, and in particular to a method for preparing a niobium-tin superconducting wire based on 3D printing. Background Art

[0002] NbSn superconducting wire has a high critical current density and is an important raw material for manufacturing high-field magnets. The internal tin method is one of the main methods for preparing NbSn superconducting wire. At present, the NbSn superconducting wires with the highest performance and the widest application in the world are all prepared by the internal tin method, which usually adopts the method of inserting tin-titanium alloy rods into internal tin NbSn copper-niobium composite rods to assemble internal tin NbSn subcomponents, and then assemble the subcomponents into tantalum tubes and oxygen-free copper tubes for multiple drawing to obtain NbSn composite wires.

[0003] At present, the niobium-tin subcomponents of the internal tin method are assembled using tin-titanium alloy rods. Due to the excess tin content, there is a problem of too little niobium-tin phase after heat treatment. At the same time, there is also an uneven distribution of the niobium-tin phase, which leads to a low critical current and limits its use in high-field magnetic fields. Summary of the invention

[0004] The embodiment of the present invention provides a method for preparing niobium-tin superconducting wire based on 3D printing, which is used to solve the problem that the niobium-tin subcomponents of the internal tin method in the prior art are assembled using tin-titanium alloy rods. Due to the excessive tin content, there is too little niobium-tin phase after heat treatment and the distribution is uneven, resulting in a low critical current, which limits its use in high-field magnetic fields.

[0005] On the one hand, an embodiment of the present invention provides a method for preparing a niobium-tin superconducting wire based on 3D printing, comprising: A tin-titanium-niobium alloy rod is obtained by depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing; After drilling a hole in the center of the tin-titanium-niobium alloy rod, insert a tin-silver alloy rod to obtain a tin-titanium-niobium-silver alloy rod; Putting the tin-titanium-niobium-silver alloy rod into the niobium-tin-copper-niobium composite tube to obtain the internal tin method niobium-tin subcomponent; Putting the internal tin method niobium tri-tin subcomponents into a tantalum tube and an oxygen-free copper tube in sequence to obtain an internal tin method niobium tri-tin blank; The internal tin method niobium-tin billet is stretched to obtain a niobium-tin superconducting wire.

[0006] In a possible implementation, the step of depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing to obtain the tin-titanium-niobium alloy rod comprises: The tin-titanium-niobium alloy rod is provided with a mesh-shaped niobium film by depositing niobium powder on the surface of the tin-titanium alloy rod under the protection of argon gas through laser melting deposition.

[0007] In a possible implementation, the niobium-tin-copper-niobium composite tube is obtained by an internal tin method.

[0008] In a possible implementation, placing the tin-titanium-niobium-silver alloy rod into a niobium-tin-copper-niobium composite tube to obtain an internal tin method niobium-tin subcomponent comprises: Cleaning the tin-titanium-niobium-silver alloy rod and the niobium-tin-copper-niobium composite tube; The tin-titanium-niobium-silver alloy rod is placed into the niobium-tin-copper-niobium composite tube and then subjected to multiple drawing steps to obtain the internal tin method niobium-tin subcomponent.

[0009] In a possible implementation, the cross section of the niobium-tin-copper-niobium composite tube is an annular structure, the annular structure is a copper-niobium alloy tube, and a niobium-tin rod is embedded in the tube wall of the copper-niobium alloy tube.

[0010] The method for preparing a niobium-tin superconducting wire based on 3D printing in the present invention has the following advantages: (1) The presence of silver is conducive to the uniform diffusion of tin during heat treatment.

[0011] (2) A mesh niobium film is deposited on the surface of the tin-titanium alloy rod by 3D printing, which ensures the accuracy and quality of the niobium film and enables more high-quality niobium-tin grains to be generated during the heat treatment of the wire, thereby improving the performance of the internal tin method niobium-tin wire. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0013] Figure 1 A flow chart of a method for preparing a niobium-tin superconducting wire based on 3D printing provided in an embodiment of the present invention; Figure 2 A schematic diagram of the structure of niobium-tin subcomponents by the internal tin method of a method for preparing niobium-tin superconducting wire based on 3D printing provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0014] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments 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.

[0015] Figure 1 A flow chart of a method for preparing a niobium-tin superconducting wire based on 3D printing provided in an embodiment of the present invention; an embodiment of the present invention provides a method for preparing a niobium-tin superconducting wire based on 3D printing, comprising: A tin-titanium-niobium alloy rod is obtained by depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing; After drilling a hole in the center of the tin-titanium-niobium alloy rod, insert a tin-silver alloy rod to obtain a tin-titanium-niobium-silver alloy rod; Putting the tin-titanium-niobium-silver alloy rod into the niobium-tin-copper-niobium composite tube to obtain the internal tin method niobium-tin subcomponent; Putting the internal tin method niobium tri-tin subcomponents into a tantalum tube and an oxygen-free copper tube in sequence to obtain an internal tin method niobium tri-tin blank; The internal tin method niobium-tin blank is stretched to obtain a niobium-tin superconducting wire; The method of depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing to obtain the tin-titanium-niobium alloy rod comprises: Depositing niobium powder on the surface of the tin-titanium alloy rod under argon protection by laser melting deposition to obtain the tin-titanium-niobium alloy rod having a mesh niobium film; The niobium-tin-copper-niobium composite tube is obtained by an internal tin method; The step of placing the tin-titanium-niobium-silver alloy rod into a niobium-tin-copper-niobium composite tube to obtain an internal tin method niobium-tin subcomponent comprises: Cleaning the tin-titanium-niobium-silver alloy rod and the niobium-tin-copper-niobium composite tube; Putting the tin-titanium-niobium-silver alloy rod into the niobium-tin-copper-niobium composite tube and then performing multiple drawing processes to obtain the internal tin method niobium-tin subcomponent; The cross section of the niobium-tin-copper-niobium composite tube is an annular structure, and the annular structure is a copper-niobium alloy tube. A niobium-tin rod is embedded in the tube wall of the copper-niobium alloy tube.

[0016] For example, Figure 2 As shown, a mesh niobium film is deposited on the surface of a cleaned tin-titanium alloy rod by 3D printing to obtain a tin-titanium-niobium alloy rod, a hole is drilled in the center of the tin-titanium-niobium alloy rod, and then a tin-silver alloy rod is inserted into the center hole of the cleaned tin-titanium-niobium alloy rod to obtain a tin-titanium-niobium-silver alloy rod, and then the tin-titanium-niobium-silver alloy rod is cleaned, inserted into a cleaned internal tin method niobium three-tin-copper-niobium composite tube, and a multi-pass drawing forming process is performed to obtain an internal tin method niobium three-tin subcomponent, and the internal tin method niobium three-tin subcomponent is sequentially placed in a cleaned tantalum tube and an oxygen-free copper tube to obtain an internal tin method niobium three-tin billet, and finally the internal tin method niobium three-tin billet is stretched to obtain a niobium three-tin superconducting wire.

[0017] Among them, the particle size of niobium powder used in 3D printing technology is 50~100μm, the laser power is 200W~500W, the scanning speed is 500mm / s~1500mm / s, the atmosphere protection is high-purity argon, the flow rate is 10L / min~20L / min, the powder thickness is 20μm~100μm, the printing direction is staggered scanning, and the preheating temperature is 100°C~200°C; the thickness of the niobium film is 50~1000μm; the size of the tin-titanium alloy rod is 15~30mm in diameter×1000~2500mm; the drilling diameter of the tin / titanium / niobium alloy rod is 5~20mm in diameter, and the size of the tin-silver alloy rod is 4.5~1 in diameter 9.5mm×1000~2500mm; the dimensions of the internal tin method niobium tin-copper-niobium composite tube are outer diameter 40~55mm / inner diameter 16.5~31.5mm×800~2200mm; the specifications of the subcomponents are height 2~15mm, semicircle 2~15mm, fan-shaped 2~15mm, and length 600~4000mm; the specifications of the tantalum tube are diameter 14.5~59.5mm and length 600~4000mm; the specifications of the oxygen-free copper tube are outer diameter 20~75mm, inner diameter 15~60mm, and length 600~4000mm; the stretching process processing rate is 2%~30%, and the stretching speed is 1~100m / min.

[0018] In a possible embodiment, a tin-titanium alloy rod with a size of φ15 mm×1000 mm is selected, and a mesh niobium film is deposited on the surface of the cleaned tin-titanium alloy rod using 3D printing technology, and the thickness of the niobium film is 50 μm; the tin-titanium-niobium alloy rod is obtained; the 3D printing technology uses a niobium powder with a particle size of 50 μm, a laser power of 200 W, a scanning speed of 500 mm / s, an atmosphere protection of high-purity argon gas, a flow rate of 10 L / min, a powder thickness of 20 μm, a printing direction of staggered scanning, and a preheating temperature of 100°C; Drill a hole in the center of the obtained tin-titanium-niobium alloy rod, the diameter of the hole is φ5mm, and put the tin-silver alloy rod into the cleaned drilled tin-titanium-niobium alloy rod to obtain a tin-titanium-niobium-silver alloy rod; the size of the tin-silver alloy rod is φ4.5mm×1000mm; The obtained tin-titanium-niobium-silver alloy rod is cleaned and then inserted into the cleaned internal tin method niobium tin-copper-niobium composite tube, and internal tin method niobium tin-copper-niobium subcomponents of different shapes are obtained through multiple drawing processes; the internal tin method niobium tin-copper-niobium composite tube has a size of φ40mm / φ16.5mm×800mm; the specifications of the subcomponents after forming are H2mm, semicircle 2mm, fan-shaped 2mm, and length 600mm; The obtained internal tin method niobium tin subcomponents are cleaned and bundled and sequentially loaded into the cleaned Ta tube and oxygen-free copper tube to obtain the final internal tin method niobium tin billet, and then stretched multiple times to obtain niobium tin superconducting wire. The specifications of the Ta tube are φ14.5mm and 600mm in length; the specifications of the oxygen-free copper tube are 20mm in outer diameter, 15mm in inner diameter, and 600mm in length; the stretching pass processing rate is 2%~30%, and the stretching speed is 1~100m / min.

[0019] After the superconducting wire was stretched to φ0.7mm, samples were taken every 100m for heat treatment and then tested for critical current under a 12T magnetic field. The test results showed that the critical current density remained at 1000A / mm2, an increase of 15%.

[0020] In a possible embodiment, a tin-titanium alloy rod with a size of φ30 mm×2500 mm is selected, and a mesh niobium film is deposited on the surface of the cleaned tin-titanium alloy rod using 3D printing technology (laser melting deposition), and the thickness of the niobium film is 1000 μm; the tin-titanium-niobium alloy rod is obtained; the 3D printing technology uses a niobium powder with a particle size of 100 μm, a laser power of 500 W, a scanning speed of 1500 mm / s, an atmosphere protection of high-purity argon gas, a flow rate of 20 L / min, a powder thickness of 100 μm, a printing direction of staggered scanning, and a preheating temperature of 200°C; Drill a hole in the center of the obtained tin-titanium-niobium alloy rod, the diameter of the hole being φ20 mm, and insert the tin-silver alloy rod into the cleaned drilled tin-titanium-niobium alloy rod to obtain a tin-titanium-niobium-silver alloy rod; the size of the tin-silver alloy rod is φ19.5 mm×2500 mm; The obtained tin-titanium-niobium-silver alloy rod is cleaned and then inserted into the cleaned internal tin method niobium tin-copper-niobium composite tube, and internal tin method niobium tin-copper-niobium subcomponents of different shapes are obtained through multiple drawing processes; the internal tin method niobium tin-copper-niobium composite tube has a size of φ55mm / φ31.5mm×2200mm; the specifications of the subcomponents after forming are H15mm, semicircle 15mm, fan-shaped 15mm, and length 4000mm; The obtained internal tin method niobium tin subcomponents are cleaned and bundled and sequentially loaded into the cleaned Ta tube and oxygen-free copper tube to obtain the final internal tin method niobium tin billet, and then stretched multiple times to obtain niobium tin superconducting wire. The specifications of the Ta tube are φ59.5mm and 4000mm in length; the specifications of the oxygen-free copper tube are 75mm in outer diameter, 60mm in inner diameter, and 4000mm in length; the stretching pass processing rate is 2%~30%, and the stretching speed is 1~100m / min.

[0021] After the superconducting wire was stretched to φ0.818mm, samples were taken every 100m for heat treatment and then tested for critical current under a 12T magnetic field. The test results showed that the critical current density remained at 1500A / mm2, an increase of 13%.

[0022] In a possible embodiment, a tin-titanium alloy rod with a size of φ20 mm×2000 mm is selected, and a mesh niobium film is deposited on the surface of the cleaned tin-titanium alloy rod using 3D printing technology (laser melting deposition), and the thickness of the niobium film is 500 μm; the tin-titanium-niobium alloy rod is obtained; the 3D printing technology uses a niobium powder with a particle size of 60 μm, a laser power of 300 W, a scanning speed of 1000 mm / s, an atmosphere protection of high-purity argon gas, a flow rate of 15 L / min, a powder thickness of 50 μm, a printing direction of staggered scanning, and a preheating temperature of 150°C; Drill a hole in the center of the obtained tin-titanium-niobium alloy rod, the diameter of the hole being φ10 mm, and insert the tin-silver alloy rod into the cleaned drilled tin-titanium-niobium alloy rod to obtain a tin-titanium-niobium-silver alloy rod; the size of the tin-silver alloy rod is φ9.5 mm×2000 mm; The obtained tin-titanium-niobium-silver alloy rod is cleaned and then inserted into the cleaned internal tin method niobium tin-copper-niobium composite tube, and internal tin method niobium tin-copper-niobium subcomponents of different shapes are obtained through multiple drawing processes; the internal tin method niobium tin-copper-niobium composite tube has a size of φ45mm / φ20.5mm×2000mm; the specifications of the subcomponents after forming are H9mm, semicircle 9mm, fan-shaped 7mm, and length 3000mm; The obtained internal tin method niobium tin subcomponents are cleaned and bundled and sequentially loaded into the cleaned Ta tube and oxygen-free copper tube to obtain the final internal tin method niobium tin billet, and then stretched multiple times to obtain niobium tin superconducting wire. The specifications of the Ta tube are φ44mm and 4000mm in length; the specifications of the oxygen-free copper tube are 63mm in outer diameter, 44.5mm in inner diameter, and 4000mm in length; the stretching pass processing rate is 2%~30%, and the stretching speed is 1~100m / min.

[0023] After the superconducting wire was stretched to φ1.0mm, samples were taken every 100m for heat treatment and then tested for critical current under a 12T magnetic field. The test results showed that the critical current density remained at 1800A / mm2, an increase of 10%.

[0024] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0025] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalents, the present invention is also intended to include these modifications and variations.

Claims

1. A method for preparing niobium-tin superconducting wire based on 3D printing, characterized in that: include: A tin-titanium-niobium alloy rod is obtained by depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing; After drilling a hole in the center of the tin-titanium-niobium alloy rod, insert a tin-silver alloy rod to obtain a tin-titanium-niobium-silver alloy rod; Putting the tin-titanium-niobium-silver alloy rod into the niobium-tin-copper-niobium composite tube to obtain the internal tin method niobium-tin subcomponent; Putting the internal tin method niobium tri-tin subcomponents into a tantalum tube and an oxygen-free copper tube in sequence to obtain an internal tin method niobium tri-tin blank; The internal tin method niobium-tin billet is stretched to obtain a niobium-tin superconducting wire.

2. The method for preparing a niobium-tin superconducting wire based on 3D printing according to claim 1, characterized in that: The method of depositing a mesh niobium film on the surface of the tin-titanium alloy rod by 3D printing to obtain the tin-titanium-niobium alloy rod comprises: The tin-titanium-niobium alloy rod is provided with a mesh-shaped niobium film by depositing niobium powder on the surface of the tin-titanium alloy rod under the protection of argon gas through laser melting deposition.

3. The method for preparing a niobium-tin superconducting wire based on 3D printing according to claim 1, characterized in that: The niobium, tin, copper and niobium composite tube is obtained by an internal tin method.

4. The method for preparing a niobium-tin superconducting wire based on 3D printing according to claim 1, characterized in that: The step of placing the tin-titanium-niobium-silver alloy rod into a niobium-tin-copper-niobium composite tube to obtain an internal tin method niobium-tin subcomponent comprises: Cleaning the tin-titanium-niobium-silver alloy rod and the niobium-tin-copper-niobium composite tube; The tin-titanium-niobium-silver alloy rod is placed into the niobium-tin-copper-niobium composite tube and then drawn to obtain the internal tin method niobium-tin sub-component.

5. The method for preparing a niobium-tin superconducting wire based on 3D printing according to claim 1, characterized in that: The cross section of the niobium-tin-copper-niobium composite tube is an annular structure, and the annular structure is a copper-niobium alloy tube. A niobium-tin rod is embedded in the tube wall of the copper-niobium alloy tube.

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