238results about How to "Improve superconductivity" patented technology

A method of preparing a biaxially textured alloy article comprises the steps of preparing a mixture comprising Ni powder and at least one powder selected from the group consisting of Cr, W, V, Mo, Cu, Al, Ce, YSZ, Y, Rare Earths, (RE), MgO, CeO2, and Y2O3; compacting the mixture, followed by heat treating and rapidly recrystallizing to produce a biaxial texture on the article. In some embodiments the alloy article further comprises electromagnetic or electro-optical devices and possesses superconducting properties.

A method of preparing a biaxially textured article comprises the steps of providing a metal preform, coating or laminating the preform with a metal layer, deforming the layer to a sufficient degree, and rapidly recrystallizing the layer to produce a biaxial texture. A superconducting epitaxial layer may then be deposited on the biaxial texture. In some embodiments the article further comprises buffer layers, electromagnetic devices or electro-optical devices.

The invention relates to a method for preparing an iron-based superconductor. The method comprises the following steps: correspondingly processing iron-based superconductor precursor powder to obtain a lumpish or strip sample; putting the lumpish or strip sample into an Ar atmosphere protected or vacuum intense magnetic field heat treatment furnace; preserving the heat under a magnetic field intensity of between 0.1 and 30 Tesla and at the temperature of between 500 and 1,500 DEG C for 0.1 to 100 hours; and cooling the sample to room temperature together with the heat treatment furnace to obtain an iron-based superconductor sample; or the method comprises the following steps: dispersing sintered iron-based superconductor powder in a solvent; ultrasonically mixing the powder and the solvent; keeping the mixture in a magnetic field with a magnetic field intensity of between 0.1 and 30 Tesla for 0.1 to 2 hours; evaporating the solvent; putting the iron-based superconductor powder which is treated in the magnetic field into an Ar atmosphere or vacuum heat treatment furnace; and preserving the heat at the temperature of between 500 and 1,500 DEG C for 0.1 to 100 hours to obtain the iron-based superconductor sample. The method can effectively improve the connectivity of crystalline grains, greatly enhances the critical current density, upper critical field and irreversible field of the iron-based superconductor and makes the practicability of the iron-based superconductor become possible.

The invention discloses a method for manufacturing a single crystal grain niobium material for a radio frequency superconducting cavity. The method comprises the following steps of: refining and purifying high-melting metallic niobium serving as a raw material to prepare niobium ingots, the crystal grain size of which is over phi 100 millimeters and the residual resistance ratio (RRR) value of which is over 300; and cutting single crystal grains, rolling in a rolling compaction manner, and preparing single crystal niobium plates or sheets by thermal treatment, wherein refining and purifying are performed on the high-melting metallic niobium for many times by adopting vacuum electron beams to produce the ingots with the crystal grain size of over phi 250 millimeters, the diameter of the biggest crystal grains is 100 to 140 millimeters, and the RRR value of the ingots is over 300.

The invention discloses a method for preparing a yttrium barium copper oxide superconducting film with high critical current density, which comprises the following concrete steps: a, preparing a precursor solution, which is to dissolve yttrium acetate, barium acetate, copper acetate and acetate of an impurity element into propionic acid according to the proportion that the stoichiometric ratio of yttrium: barium: copper: impurity element is 1: 2: 3-X: X (the X is more than or equal to 0.0002 and less than or equal to 0.008) to obtain the precursor solution, and the impurity element is one of Co, Fe, Zn, Ni, and Li; b, adding a polymer material polyvinyl butyral (PVB) into the precursor solution obtained in a step to obtain a coating colloid; c, coating and drying the coating colloid on a substrate to form a film; and d, performing thermal decomposition treatment on the substrate with the film prepared in c step and then imaging thermal treatment to obtain the YBCO superconducting film. The yttrium barium copper oxide superconducting film prepared by the method has high biaxial texture, smooth and compact surface, high critical current density under a magnetic field, low cost, and simple process, and is suitable for mass industrial production.

The present invention provides a generic method of preparing a metal matrix composite with a textured compound. A "roller-skate" structure starting powder with a mixture of plate-like particles and smaller particles provides better flow compatibility, higher packing density, better densification and texture formation in preparing a metal matrix composite with a textured compound. In particular, the invention provides a method of preparing a textured superconducting composite wire with an improved critical current density.

Disclosed is a method of splicing ReBCO high temperature superconductors (HTSs), which ensures excellent superconductivity after splicing. The method of splicing 2G ReBCO HTSs allows a superconductors-spliced assembly to exhibit excellent superconductivity by direct contact of high temperature superconducting layers of two strands of 2G ReBCO HTSs and solid state atoms diffusion pressurized splicing there between at a ReBCO below peritectic reaction temperature in a vacuum, and enables loss of superconductivity caused by loss of oxygen due to transport and out-diffusion of oxygen to atoms during splicing to be recovered through oxygenation annealing.

A precursor for manufacturing a Nb₃Sn superconducting wire according to the present invention includes a mono-element wire including a Sn or Sn-based alloy core disposed at the, a Cu or Cu-based alloy matrix and a plurality of Nb or Nb-based alloy filaments surrounding the Sn or Sn-based alloy core, and a diffusion barrier layer and a stabilizing copper layer surrounding the Cu or Cu-based alloy matrix. In a final shape after a reduction process, the average diameter of the Nb or Nb-based alloy filaments is set to 5 μm to 30 μm, and the average distance between the Sn or Sn-based alloy core and the Nb or Nb-based alloy filaments nearest the Sn or Sn-based alloy core is set to 100 μm or less.

The invention provides a method for preparing YBCO superconducting film target materials. The method comprises the following: A, a step of preparing YBCO superconducting-phase powder; B, a step of preforming, which is to put the powder prepared in a step A in a die, compress the powder by use of the pressure of between 20 and 30 MPa on a press so as to manufacture a sheet, put the sheet obtained through compression in a rubber sleeve, perform cold isostatic pressing under the pressure of between 150 and 200 MPa and obtain a superconducting sheet; C, a step of sintering the sheet, which is to sinter the superconducting sheet obtained in a step B in a box-type furnace for 20 to 30 hours at a sintering temperature of between 850 and 960 DEG C; and D, a step of performing oxygen permeation, which is to put the superconducting sheet sintered in a step C in a tubular furnace, perform oxygen permeation treatment for 2 to 3 hours at a temperature of between 450 and 500 DEG C and obtain the target material. The target material prepared by the method has the advantages of uniformity, good shape, high density and good superconducting performance. In addition, the method is low in cost and suitable for the mass production of the target material.

A superconductive element containing Nb₃Sn, in particular a multifilament wire, comprising at least one superconductive filament (8) which is obtained by a solid state diffusion reaction from a preliminary filament structure (1), said preliminary filament structure (1) containing an elongated hollow pipe (2) having an inner surface (3) and an outer surface (4), wherein said hollow pipe (2) consists of Nb or an Nb alloy, in particular NbTa, wherein the outer surface (4) is in close contact with a surrounding bronze matrix (5) containing Cu and Sn, and wherein the inner surface (3) is in close contact with an inner bronze matrix (5) also containing Cu and Sn, is characterized in that the inner bronze matrix (5) of the preliminary filament structure (1) encloses in its central region an elongated core (6) consisting of a metallic material, said metallic material having at room temperature (=RT) a thermal expansion coefficient α_core<17*10⁻⁶K⁻¹, preferably α_core≦8*10⁻⁶ K⁻¹, said metallic material having at RT a yield strength R_p0.2>300 MPa, said metallic material having at RT an elongation at rupture A>20%, and wherein the metallic material of the core (6) is chemically inert with respect to the material of the inner bronze matrix (5) up to a reaction temperature T of the solid state diffusion reaction. This element has improved superconductive properties in a large volume fraction of its superconductive filaments, in particular a high critical temperature T_c and a high critical magnetic filed strength B_c2, and is mechanically stable enough for commercial applications such as magnet coils.

The invention relates to a method for preparing a REBa2Cu3Ox (REBCO) high-temperature superconducting block material, in particular to a melt texture growth (MTG) method for the REBCO high-temperature superconducting block material. The MTG method for the REBCO high-temperature superconducting block material comprises the following steps of: a) mixing raw materials; b) grinding and calcining to obtain a superconducting material rough blank; c) tabletting; d) firing; and e) cooling to obtain the REBCO high-temperature superconducting block material, namely e1) cooling to buffer temperature, and preserving heat, e2) cooling to growth temperature, and preserving heat, and e3) quenching. By the method, the technical problem that the REBCO high-temperature superconducting block material fails to grow because spontaneous nucleation is generated when temperature is reduced from the maximum temperature to the growth temperature in the conventional MTG method is solved.

The invention relates to a Eu-Fe-As superconductor and a wire and tape preparing method. The wire and tape preparing method comprises the following steps: (1) after raw material powder which is prepared according to a chemical formula: Eu1-xAxM2Pn2 is evenly mixed, the raw material powder is put into a metal pipe and is sufficiently tamped, then both ends of the metal pipe are sealed; (2) the metal pipe is rotatablely forged, drawn and rolled according to 5 to 20 percent of pass deformation to obtain a rod, a wire or a tape; (3) the rod, the wire or the tape which is processed by the step (2) is put into a high-temperature heating furnace and vacuumized to 10<-2>-10<-5> Pa at room temperature, then argon is inflated into the high-temperature heating furnace, and then the temperature of the high-temperature heating furnace is kept for 5 to 60 hours at the temperature of 600 to 1000 DEG C, and finally, the high-temperature heating furnace is cooled to the room temperature to obtain the Eu-Fe-As novel superconductor. Compared with the common stepping preparing method, the wire and tape preparing method is safe and reliable, a sintering process can be completed once, the technology is simple, the production efficiency is high, the density of the prepared Eu-Fe-As compound superconductor is higher, and the Eu-Fe-As superconductor has good superconduction performance.

The invention discloses a method for manufacturing a composite Nb3Al/Nb multi-core superconducting wire. The method comprises the following steps of: weighting Nb foil and Al foil based on a stoichiometric ratio of the Nb3Al; superposing the Nb foil and the Al foil and winding the Nb foil and the Al foil around a Nb rod, placing the Nb rod into a Nb tube, and drawing the Nb tube to a thin line of0.8-1mm to obtain a single-core wire; orderly placing the sections of the single-core wire into the Nb tube after cutting off the single-core wire to be multiple equal-length sections, and placing anequal-length Nb rod on the central axial line of the Nb tube; drawing and rolling the Nb tube to a circular or flat wire with the diameter of 1-2.5mm to obtain a multi-core wire; and cutting off the multi-core wire to short wires of 10cm, and carrying out a high-temperature treatment of 1900-2100 DEG C on the short wires for 0.05-0.2s by utilizing a pulse electric power under a vacuum condition to obtain the composite Nb3Al/Nb multi-core superconducting wires. The method disclosed by the invention has the advantages of short manufacturing period and high efficiency; in addition, the compositeNb3Al/Nb multi-core superconducting wire manufactured by the method has the advantages of compact connection, good uniformity, no separation situation, no impurity phase, and excellent superconducting performance.

An electrically alterable thin film memory device or non-volatile trigger which can be switched from a high resistance state to a low resistance state. The device increases the concentration of electrically active impurities at correspondent electrodes to which respect impurities would electro migrate during a large number of set-reset cycles. The device comprises a layered structure with memory layers formed on an interface of two regions as the result of the mutual mixing and migration of their constituents. One region contains an electrically active donor impurity. A thin layer of dielectric is placed in the other region. Each of the memory layers includes an interface of chalcogenide films.

It is an objective of the present invention to provide a method for manufacturing long lengths of MgB₂ superconducting wire having excellent superconducting properties and an MgB₂ superconducting wire manufactured thereby. There is provided a method for manufacturing a magnesium diboride superconducting wire, comprising the successive steps of: filling a metallic tube with a raw material powder; and subjecting the tube to wiredrawing processing, in which a fatty acid metal salt or a mixture of the fatty acid metal salt and a fatty acid is added to the raw material powder.

The invention provides a simplified CeO2/LaZrO3 composite separating layer used for a second generation high temperature superconductive tapes and its preparation method. According to the invention, a simplified CeO2/LaZrO3 double layers composite separating layer structure replaces a complex CeO2/YSZ/CeO2 and CeO2/YSZ/Y2O3 three layers composite separating layer, and a multichannel laser plated film technology replaces a traditional reacting direct current magnetron sputtering technology for preparing a composite separating layer structure on a Ni-W metal substrate. The invention has the advantages of stability, repeatability and reliability. The chemical property of the obtained CeO2/LaZrO3 composite separating layer is stable, and has the characteristics of single(001) orientation, small thickness error and good surface fineness. A rare earth oxide superconducting layer (REBCO) prepared on the composite separating layer has superior superconductive performance, and is capable of satisfying the requirement for manufacturing a superconductive electric power device.

The invention discloses an explosive welding manufacturing method of a high-purity niobium-oxygen-free copper composite plate. The method comprises the following steps that a high-purity niobium plateserves as a composite plate, an oxygen-free copper plate is used as a substrate, and high-purity niobium is manufactured in an explosive welding mode; and the quality purity of the high-purity niobium plate is not less than 99%, the thickness of the high-purity niobium plate is not larger than 2 mm, the oxygen content in the oxygen-free copper plate is less than 2 ppm, and the thickness of the oxygen-free copper plate is larger than 10 mm. According to the method, the composite surface of the high-purity niobium plate and the oxygen-free copper plate are subjected to high-speed collision through explosion welding to form a solid-phase metallurgical bonding to be combined, the defect that the oxidation of the high-purity niobium plate and oxygen absorption of the oxygen-free copper plate in the heating rolling process are avoided, the problem that the high-purity plates with relatively large elongation rates are difficult to cold rolling and rolling is solved, and the excellent superconducting performance of the high-purity niobium material is kept, and meanwhile, the thickness of a superconducting cavity is increased by the oxygen-free copper plate, and thus the mechanical stability of the superconducting cavity is enhanced.

The invention relates to a method for manufacturing a yttrium barium copper oxide target, which comprises the following steps of: (1) uniformly mixing Y2O3, BaO and CuO according to a certain ratio (the atomic ratio of Y:Ba:Cu=1:2:3) to obtain mixed powder, wherein the primary particle size of Y2O3, BaO and CuO is 100-300 nm, and the purity is greater than 99.9 wt%; (2) performing cold pressing on the mixed powder with a four-column hydraulic press, wherein the cold pressing pressure is 200-300 MPa; (3) placing the mixture in an oxygen normal-pressure sintering furnace, sintering the mixture at 800-950 DEG C, cooling the mixture after sintering is completed, taking out the mixture at normal pressure, and crushing the mixture into powder with 30-500 meshes; (4) performing cold pressing on the powder with the four-column hydraulic press to form a blank, wherein the cold pressing pressure is 30-50 MPa; (5) performing cold isostatic pressing on the blank, wherein the pressure is 200-300 MPa; and (6) sintering the blank in a furnace. The yttrium barium copper oxide target manufactured by the method has small grain size and high density.