JPH02192622A - Manufacture of superconductive wire material - Google Patents

Abstract

PURPOSE:To intend poly-crystallization of high orientation and density by rotating a coil mold filled with material around an axis while applying magnetic field in an axial-length direction to manufacture a wire material. CONSTITUTION:A coil mold 1 in which material is housed is mounted in an electric oven 2 to apply magnetic field of 10-200kOe to the coil mold 1 in an axial-length direction, and while performing annealing treatment at about 960-1050 deg.C by a heater 3 the coil mold 1 is rotated in rotating speed of 1000-10000rpm or so around the axis in an arrow mark direction. As a result, because of the magnetic field applied to the coil mold 1 in an axial-length direction, a (c) axis grows in an axial-length direction and (a) and (b) axes grow in a circular direction to the coil mold 1, so that polycrystals can be deposited to manufacture a coil wire material with superconductive property. At this time, centrifugal force applied in a non-white arrow mark direction realizes crystals of higher density, and 211-phase fine crystals in this crystal structure with pinning force on increase makes current density higher.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a method for producing a superconducting wire having a highly pinning polycrystalline structure and having high current density characteristics even in a high magnetic field environment. be.

[Conventional technology]

In oxide-based superconducting materials, high current density (Jc
), it is necessary that the current direction be parallel to the C axis of the crystal orientation. Polycrystals with high density, high orientation, and high pinning have a high current density in the shell of several thousand to 10,000 A/CIA (0 magnetic field), and are exposed to a high magnetic field environment of several tens of koe. Even if there is a current density, the current density decreases by only a few percent, which is an excellent characteristic.

[Problem to be solved by the invention]

However, an effective method for manufacturing wire rods such as coils made of polycrystals having the above-mentioned characteristics has not yet been proposed.

The present invention has been made in view of the above circumstances, and by applying centrifugal force and a magnetic field in a certain direction to the raw material, it is possible to easily produce a wire made of polycrystals with high density, high orientation, and high pinning. An object of the present invention is to provide a method for manufacturing a superconducting wire that can be manufactured.

[Means to solve the problem]

A first manufacturing method according to the present invention is a method for manufacturing a superconducting wire material having high current density characteristics regardless of the magnetic field environment, in which a raw material is formed into a cylindrical coil shape with a spiral inner surface. A second manufacturing method according to the present invention is characterized in that a magnetic field is applied in the axial direction of the coil mold, and the coil mold is rotated about the axis while annealing the raw material. A method for manufacturing a superconducting wire having high current density characteristics regardless of the method, in which a molten raw material is placed in a cylindrical coil mold whose inner peripheral surface forms a spiral surface, and a magnetic field is applied in the axial direction of the coil mold. is applied, and the coil mold is rotated around its axis while slowly cooling the molten raw material.

[Effect]

In the manufacturing method of the present invention, a raw material is first placed in a cylindrical coil mold. Next, while annealing or slow cooling is performed depending on the material of the raw material, a magnetic field is applied in the axial direction of the coil mold, and the coil mold is rotated about the axis.

Then, the C axis grows in the axial direction of the coil mold, and the a, b axes grow densely in the circumferential direction of the coil mold, and each a, b,
Polycrystals aligned with the c-axis in a fixed direction are precipitated at high density.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below based on drawings showing embodiments thereof.

In the method for manufacturing a superconducting wire according to the present invention, there are some differences in the manufacturing process depending on the type of raw material used. In other words, there is a slight difference in the manufacturing process between when amorphous powder or ultrafine particles kneaded with organic matter is used as a raw material and when a material molten at a high temperature is used as a raw material.

First, a manufacturing method using amorphous powder or ultrafine particles kneaded with an organic substance as a raw material will be described. Figure 1 is a schematic diagram showing the implementation state of this manufacturing method, Figure 2 is a schematic diagram showing the implementation state of this manufacturing method.
The figures are a front view and a sectional view of a coil mold 1 used in this manufacturing method.

The coil mold 1 has a cylindrical shape made of Pt+Ag+Zr0z or the like, and a spiral surface for manufacturing a superconducting coil wire is formed on its inner peripheral surface.

First, in this coil mold 1, an amorphous (for example, Yfla2Cu30t) kneaded with an organic material or a 0.1 μm
Contains ultrafine particles. Next, the coil mold 1 containing the raw material is placed in the electric furnace 2, a magnetic field of 10 to 200 kOe is applied in the axial direction of the coil mold 1, and the heater 3
While annealing at a temperature of about 60 to 1050°C, the coil type I is heated to 1000 to 110°C in the direction of the arrow, centering on the axis.
Rotate at a rotation speed of about 000 rpm.

Then, since a magnetic field is applied in the axial direction (■ direction in the figure) of the coil type 1, the C-axis grows in the axial direction,
The a and b axes grow in the circumferential direction of the coil mold 1, and polycrystals are precipitated, making it possible to manufacture a coil wire having superconducting properties. At this time, since centrifugal force is applied in the direction of the white arrow in the figure, it is possible to increase the density of the crystal, and in this crystal, (211) phase microcrystals increase the pinning force. Therefore, the current density can be improved.

Next, a case will be described in which a molten material in a high temperature state is used as the raw material. First, a LnBazCu=0+ series raw material (Ln is a tantanium-based element of the Y main raw material) melted at about 1360°C is injected into the coil mold l. Next, the coil mold 1 injected with this raw material is charged into the electric furnace 2, and
A magnetic field of 200 kOe was applied in the axial direction of the coil mold 1, and while the coil mold 1 was slowly cooled from the molten state at a rate of about 1°C per minute, the coil mold 1 was rotated 100 kOe in the direction of the arrow around the axis.
Rotate at a rotation speed of about 0 to 110,000 rpm.

Then, as in the manufacturing example described above, the C axis grows in the axial direction of coil mold 1, and a and b grow in the circumferential direction of coil mold 1.
The shaft grows, polycrystals precipitate, and a coil wire having superconducting properties can be manufactured. At this time, it is possible to achieve higher crystal density and higher current density, as in the above-mentioned manufacturing example.

The graph shown by the solid line in FIG. 3 shows the current density magnetic field characteristics of the coil wire manufactured using the manufacturing method of the present invention, where the vertical axis is the current density Jc (A/CIA) and the horizontal axis is the current density Jc (A/CIA). The external magnetic field H (kOe) is shown. The graph shows the characteristics at a temperature of 77K, and as a reference example, the change in characteristics of a conventional coil wire is shown by a broken line. Compared to conventional examples in which the current density characteristics deteriorate significantly as the external magnetic field increases, the coil wire produced by the manufacturing method of the present invention has a current density characteristic of only a few percent even when the external magnetic field increases to 100 k Oe or more.
Only moderate deterioration can be seen. As a result, it is proven that the manufacturing method of the present invention can manufacture a superconducting wire having high current density characteristics even in a high magnetic field environment.

〔Effect of the invention〕

As detailed above, in the manufacturing method of the present invention, the wire rod is manufactured by rotating the coil mold containing the raw material around the axis while applying a magnetic field in the longitudinal direction of the axis, so that the C-axis is the axis of the coil mold. Highly oriented polycrystals can be precipitated by growing the a and b axes in the circumferential direction of the coil shape in the longitudinal direction, and high-density polycrystals can be precipitated by centrifugal force accompanying rotation. be able to.

Further, the present invention has excellent effects such as being able to easily manufacture a superconducting wire with little deterioration in current density characteristics even in a high magnetic field environment.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the state of implementation of the method for manufacturing a superconducting wire according to the present invention, FIG. 2 is a front view and a cross-sectional view of a coil mold used to implement the manufacturing method, and FIG. It is a graph which shows the current density-magnetic field characteristic of the coil wire manufactured by the manufacturing method. ■...Coil type 2...Electric furnace 3...Heater patent Applicant Sanyo Electric Co., Ltd. agent Patent attorney
Noboru Kono Funeral map with human hands

Claims (1)

[Claims] 1. A method for manufacturing a superconducting wire having high current density characteristics regardless of the magnetic field environment, which comprises: placing a raw material in a cylindrical coil mold whose inner peripheral surface forms a spiral surface; A method for manufacturing a superconducting wire, comprising: applying a magnetic field in the axial direction of the coil mold, and rotating the coil mold around the axis while annealing the raw material. 2. A method for manufacturing a superconducting wire having high current density characteristics regardless of the magnetic field environment, which involves placing a molten raw material into a cylindrical coil mold whose inner peripheral surface forms a spiral surface, and A method for manufacturing a superconducting wire, comprising applying a magnetic field in the longitudinal direction and rotating the coil mold around its axis while slowly cooling the molten raw material.