Continuous rapid laser coating method of superconducting layer in second-generation high-temperature superconducting strip

Abstract

The invention provides a continuous rapid laser coating method of a superconducting layer in a second-generation high-temperature superconducting strip. According to the invention, through a method of bi-dimensionally scanning a superconducting target along an x-y axle, the whole surface of the target can be utilized and a laser evaporation coating process can be stably and sustainably carried out; coating intervals are increased through a method of scanning along the motion direction of the strip by use of laser spots; and the width of the coating interval vertical to the motion direction of the strip is increased through a method of twining the strip on a belt roller above a heater multiple times. By using the method provided by the invention, evaporated substances are fully collected on a metal base band to the greatest extend, thereby effectively improving the preparation speed of the strip, increasing the utilization rates of the target and the evaporated substances, greatly improving the production efficiency and reducing the production cost of the strip. According to the method provided by the invention, the rapid coating of the second-generation high-temperature superconducting strip suitable for large-scale industrial production can be realized.

Description

technical field [0001] The invention relates to the field of manufacturing new-type oxide high-temperature superconducting strips, in particular to a continuous and rapid laser coating method for superconducting layers in second-generation high-temperature superconducting strips. Background technique [0002] Superconducting materials have been highly concerned by the scientific and industrial circles since the accidental discovery by the Dutch scientist Onnes in 1911. Scientists have been working hard to find room temperature (room temperature or close to room temperature) superconductors for large-scale applications and the benefit of mankind. Traditional superconducting materials are generally metals and alloys. The highest superconducting transition temperature of such materials is 23.2K. At present, niobium-titanium alloys are mainly used in the field of nuclear magnetic resonance imaging. The refrigeration cycle medium is liquid helium. called low-temperature supercon...

AI Technical Summary

Problems solved by technology

Although the first generation of high-temperature superconducting tapes has been commercially produced, it is still unable to be widely applied due to obstacles such as cost performance.

The main reasons are as follows: First, the first-generation high-temperature superconducting tapes represented by bismuth-based tapes cannot compare with yttrium-barium-copper-oxygen high-temperature superconducting tapes in terms of their superconducting current density and current transmission performance.

And after more than ten years of research and development, there is limited room for further improvement

Second, the superconducting current of the bismuth tape decays quickly in the magnetic field, that is, in the external magnetic field, when the magnetic field strength exceeds a certain value, it will lose its superconductivity

However, most applications in the energy and power fields are often related to strong magnetic fields, so the first generation of high-temperature superconducting tapes cannot be applied in most magnetic fields above medium strength

Third, because silver is a precious metal, the cost of raw materials is relatively high, so it is difficult to reduce the cost of the first-generation bismuth-based high-temperature superconducting strips produced by the "silver-coated" method to a price that competes with traditional copper wires

Disadvantages: poor mechanical properties and weak magnetism; in addition, the surface is easily oxidized at high temperature, which increases the difficulty and complexity of epitaxial growth isolation layer

Therefore, this method can only meet the preparation of short sample strips for laboratory research, and cannot realize the preparation of kilometer-level second-generation high-temperature superconducting strips that meet the requirements of industrial applications.

Moreover, when the superconducting target only adopts the rotation mode, the laser spot is only incident on such as image 3 In the annular zone of the target surface shown, the utilization rate of the target is very low, resulting in an increase in superconducting target consumables, which is not conducive to achieving the low-cost goal required by industrial production

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