A method for rapidly preparing MgB2 superconducting wire for MRI

Abstract

The present application belongs to the technical field of superconducting material processing, and particularly relates to a method for rapidly preparing MgB2 superconducting wire for MRI, which comprises the following steps: placing a solder with a melting point in a phase formation temperature range of MgB2 in an inlaying device to melt into a liquid, and controlling the temperature in the phase formation temperature range of MgB2; after the solder is melted into the liquid, placing the MgB2 superconducting wire in the inlaying device so that the MgB2 superconducting wire is located in an inlaying position; introducing the liquid solder to the MgB2 superconducting wire, and when the MgB2 superconducting wire is submerged to a required height, inlaying is performed, and in the inlaying process, the MgB2 is phase formed. The preparation method of the present application can shorten the preparation process, and reduce the preparation cost and preparation time.

Description

Technical Field

[0001] This invention belongs to the field of superconducting material processing technology, and relates to a method for preparing MgB2 superconducting wire for MRI. Background Technology

[0002] MgB2 is an intermetallic superconducting compound with a superconducting transition temperature of 39 K. Due to its advantages such as long coherence length, low anisotropy, absence of weak connections at grain boundaries, low raw material costs, and low refrigeration costs, MgB2 superconducting wires have high application value in medical magnetic resonance imaging (MRI) and magnetic field magnet applications.

[0003] With the advancement of global medical and health advancements, magnetic resonance imaging (MRI) technology has been widely applied in the medical field. Superconducting magnets, wound with superconducting wire, are one of the most crucial components of MRI scanners, leading to a surge in demand for superconducting wire and an urgent need for the rapid industrialization of this technology. Currently, the main magnets utilize high-cost NbTi cryogenic superconducting wire, cooled entirely by liquid helium immersion, resulting in high cooling and maintenance costs. Since liquid helium is a non-renewable and strategic resource, its global supply is extremely limited, with existing deposits completely monopolized by the United States, Japan, and Europe. Therefore, developing a crucial cooling method is imperative.

[0004] MgB2 superconductors can operate within the temperature range of GM refrigerators. MRI systems based on this novel MgB2 superconductor will eliminate the expensive and complex liquid helium conditions required by current low-temperature superconducting MRI systems. Compared to other high-temperature superconducting materials, MgB2 also has the advantages of simple fabrication processes and low material cost. MgB2 wire is the foundation and key component of MgB2 superconducting MRI systems. Currently, the process involves embedding WIC wire followed by heat treatment to form the MgB2 wire phase. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to achieve phase formation while embedding MgB2 superconducting wire. The embedding is performed by solder with a melting point within the phase formation temperature range of MgB2 wire, so that MgB2 is formed at the same time as embedding, reducing the preparation process and saving preparation time and cost.

[0006] To solve the above-mentioned technical problems, the present invention provides a method for rapidly preparing MgB2 superconducting wires for MRI, comprising the following steps:

[0007] 1) Place the solder, whose melting point is within the MgB2 phase formation temperature range, into the mounting device and melt it into a liquid, with the temperature controlled within the MgB2 phase formation temperature range;

[0008] 2) After the solder melts into a liquid, place the MgB2 superconducting wire in the mounting device and position it in the mounting position;

[0009] 3) When the liquid solder is directed to the MgB2 superconducting wire and submerged to the required height, it is inlaid. During the inlay process, MgB2 forms a phase.

[0010] Preferably, in step 1), the solder is Ag34CuZnSn solder.

[0011] Preferably, the Ag34CuZnSn solder has the following composition by mass percentage: Ag: 33.0-35.0%, Cu: 35.0-37.0%, Zn: 25.5-29.5%, Sn: 2.0-3.0%, with the remainder being impurities not exceeding 0.15%.

[0012] Preferably, in step 1), the melting temperature of the Ag34CuZnSn solder is 630℃~730℃.

[0013] The beneficial effects of this invention are: using solder with a melting point within the MgB2 phase formation temperature range for embedding, MgB2 is formed simultaneously with embedding, reducing the preparation process and saving preparation time and cost. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the inlay device structure. Detailed Implementation

[0015] The method for rapid preparation of MgB2 superconducting wires for MRI of the present invention comprises the following steps:

[0016] 1) Place the solder, whose melting point is within the MgB2 phase formation temperature range, into the mounting device and melt it into a liquid, with the temperature controlled within the MgB2 phase formation temperature range;

[0017] 2) After the solder melts into a liquid, place the MgB2 superconducting wire in the mounting device and position it in the mounting position;

[0018] 3) When the liquid solder is directed to the MgB2 superconducting wire and submerged to the required height, it is inlaid. During the inlay process, MgB2 forms a phase.

[0019] The phase formation temperature range of MgB2 is 600–800℃.

[0020] The MgB2 superconducting wires used below were purchased from Western Superconducting Materials Technology Co., Ltd.

[0021] The WIC superconducting wire embedding device used in MRI is a patented technology developed by Western Superconducting Materials Technology Co., Ltd., with patent number 201910330956.0 and patent name "A WIC superconducting wire embedding device for MRI".

[0022] See Figure 1 The WIC superconducting wire embedding device for MRI includes a solder bath 6, an electric heating plate 9, a solder pump assembly 3, a solder channel 12, and a functional solder bath 7. The electric heating plate 9 is closely attached to the bottom and outer surface of the solder bath 6. The solder channel 12 is located inside the solder bath 6. One end of the solder channel 12 has a solder inlet 11 and is equipped with the solder pump assembly 3. The other end of the solder channel 12 is connected to the functional solder bath 7. The solder pump assembly 3 includes a motor 1, a transmission synchronous belt 2, a transmission shaft 4, an impeller 10, and an anti-oxidation cover 5. The motor 1 is equipped with the transmission synchronous belt 2, which is connected to the impeller 10 through the transmission shaft 4. The transmission shaft 4 is equipped with an anti-oxidation cover 5. The device also includes a control system 8 to control the start and stop of the electric heating plate 9. All parts of the superconducting wire embedding device that come into contact with the solder liquid are coated with ceramic to prevent the high-temperature solder liquid from corroding the components. The functional solder bath 7 is designed with an inlet and an overflow channel. A baffle is designed outside the inlet to prevent solder liquid from splashing. The overflow channel adopts a closed structure, with both the inlet and outlet located inside the solder slurry, preventing the flowing solder slurry from contacting air and greatly reducing the oxidation of the solder slurry. The functional solder tank 7 is equipped with a mold base for mounting molds and completing the embedding process.

[0023] The solder used below is Ag34CuZnSn solder, with the following composition by mass percentage: Ag: 33.0-35.0%, Cu: 35.0-37.0%, Zn: 25.5-29.5%, Sn: 2.0-3.0%, and the remainder being impurities not exceeding 0.15%. The melting point of Ag34CuZnSn solder is between 630℃ and 730℃.

[0024] The present invention will be further described in detail below with reference to specific embodiments:

[0025] Example 1

[0026] 1) After placing the solder into the solder bath 6 and setting the temperature parameters in the control system 8 according to the process requirements, start the heating button and the electric heating plate 9 will start to be powered on and heated.

[0027] 2) After the solder melts into a liquid and the temperature of the solder in the solder bath 6 reaches 630°C, the MgB2 superconducting wire is passed through the baffle, inlet, mold and mold base in the functional solder bath 7 in sequence.

[0028] 3) After the MgB2 superconducting wire reaches the mounting position, the motor is started to draw the liquid solder from the solder bath 6 through the solder inlet into the solder channel 12, and then transport it to the functional solder bath 7 so that the liquid solder submerges the MgB2 superconducting wire to a suitable height, and mounting begins; since the temperature of the liquid solder is within the superconducting transition temperature range of MgB2 during mounting, phase formation occurs simultaneously with mounting.

[0029] 4) A section of the completed MgB2 superconducting wire was cut for metallographic analysis. Its structure was uniform and met the requirements for MRI.

[0030] Example 2

[0031] 1) After placing the solder into the solder bath 6 and setting the temperature parameters in the control system 8 according to the process requirements, start the heating button and the electric heating plate 9 will start to be powered on and heated.

[0032] 2) After the solder melts into a liquid and the temperature of the solder in the solder bath 6 reaches 680°C, the MgB2 superconducting wire is passed through the baffle, inlet, mold and mold base in the functional solder bath 7 in sequence.

[0033] 3) After the MgB2 superconducting wire reaches the mounting position, the motor is started to draw the liquid solder from the solder bath 6 through the solder inlet into the solder channel 12, and then transport it to the functional solder bath 7 so that the liquid solder submerges the MgB2 superconducting wire to a suitable height, and mounting begins; since the temperature of the liquid solder is within the superconducting transition temperature range of MgB2 during mounting, phase formation occurs simultaneously with mounting.

[0034] 4) A section of the completed MgB2 superconducting wire was cut for metallographic analysis. Its structure was uniform and met the requirements for MRI.

[0035] Example 3

[0036] 1) After placing the solder into the solder bath 6 and setting the temperature parameters in the control system 8 according to the process requirements, start the heating button and the electric heating plate 9 will start to be powered on and heated.

[0037] 2) After the solder melts into a liquid and the temperature of the solder in the solder bath 6 reaches 730°C, the MgB2 superconducting wire is passed through the baffle, inlet, mold and mold base in the functional solder bath 7 in sequence.

[0038] 3) After the MgB2 superconducting wire reaches the mounting position, the motor is started to draw the liquid solder from the solder bath 6 through the solder inlet into the solder channel 12, and then transport it to the functional solder bath 7 so that the liquid solder submerges the MgB2 superconducting wire to a suitable height, and mounting begins; since the temperature of the liquid solder is within the superconducting transition temperature range of MgB2 during mounting, phase formation occurs simultaneously with mounting.

[0039] 4) A section of the completed MgB2 superconducting wire was cut for metallographic analysis. Its structure was uniform and met the requirements for MRI.

[0040] As can be seen from the above, the present invention uses solder with a melting point within the MgB2 phase formation temperature range as the embedding solder, which can significantly save the preparation time and reduce the cost of WIC MgB2 superconducting wires for MRI. The prepared MgB2 superconducting wires have uniform phase formation and stable performance, meeting the requirements for MRI preparation.

Claims

1. A method for rapid preparation of MgB2 superconducting wire for MRI, comprising the following steps: 1) Place the solder, whose melting point is within the MgB2 phase formation temperature range, into the mounting device and melt it into a liquid, with the temperature controlled within the MgB2 phase formation temperature range; 2) After the solder melts into a liquid, place the MgB2 superconducting wire in the mounting device and position it in the mounting position; 3) When the liquid solder is directed to the MgB2 superconducting wire and submerged to the required height, it is inlaid. During the inlay process, MgB2 forms a phase.

2. The method for rapid preparation of MgB2 superconducting wire for MRI according to claim 1, characterized in that, In step 1), the solder is Ag34CuZnSn solder.

3. The method for rapid preparation of MgB2 superconducting wire for MRI according to claim 2, characterized in that, The Ag34CuZnSn solder, by mass percentage, has the following composition: Ag: 33.0-35.0%, Cu: 35.0-37.0%, Zn: 25.5-29.5%, Sn: 2.0-3.0%, with the remainder being impurities not exceeding 0.15%.

4. The method for rapid preparation of MgB2 superconducting wire for MRI according to claim 2, characterized in that, In step 1), the melting temperature of Ag34CuZnSn solder is 630℃~730℃.

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