Leghe superconelucanti di niobio-titanio

Niobium-titanium superconelucting alloys

Among the existing superconducting technologies, niobium-titanium superconducting alloy is the most widely used superconducting material.
The Nb-Ti alloy with a mass ratio of nearly 1:1 has good superconducting properties. Its superconducting critical transition temperature Tc=9.5K can operate at the temperature of liquid helium. It can transmit Current density Jc≥105A/cm2 (4.2K); the highest application field can reach 10T (100,000 Gs) (4.2K).
The alloy also has excellent processing performance, and superconducting wire and strip products can be obtained through traditional smelting, processing and heat treatment processes.
Therefore, after starting research in the 1960s, it quickly entered industrial scale production.
The annual output of the United States reached 100 tons in the late 1970s; China also built a trial production line around the 1980s.

Practical Nb-Ti superconducting materials are mostly simple binary alloys, containing 35% to 55% Nb; some tantalum and zirconium can be added to improve superconducting properties.
Due to the stability of superconductivity, pure copper, pure aluminum or copper-nickel alloy is often used as the matrix material for Nb-Ti superconducting materials, and multiple Nb-Ti thin cores are inlaid to form composite multi-core superconducting materials.
A superconducting wire can contain dozens to tens of thousands of Nb-Ti cores, and the minimum core diameter can reach 1 μm.
In addition, depending on the application occasion, the multi-core wire is often twisted and transposed to reduce loss and increase electromagnetic stability.

The basic processing technology of Nb-Ti superconducting materials is: smelting pure titanium and pure niobium into alloy ingots with consumable electric arc furnace or plasma furnace, and then hot-extruding to open billets, and then hot-rolling and cold-drawing into rods; Then insert the Nb-Ti alloy rod into the oxygen-free copper tube as the matrix material to form a single mandrel; and process it into a multi-core Nb-Ti superconducting wire and strip through multiple composite assemblies.
The material needs to be subjected to multiple large cold working (processing rate above 90%) and low temperature (below 400°C) aging heat treatment, so that the superconductor can obtain enough effective pinning centers and improve the superconducting performance of the superconducting material.
Due to the characteristics of no Joule heat loss brought about by the zero resistance effect of superconductors, and the ability of Nb-Ti superconductors to carry high transport currents under strong magnetic fields, Nb-Ti superconductors are especially suitable for electricians with large currents and strong magnetic fields. field application.
For example: high-field magnets, generators, motors, magnetic fluid power generation, controlled thermonuclear reactions, energy storage devices, high-speed maglev trains, ship electromagnetic propulsion and power transmission cables, etc.

So far, the most successful applications of Nb-Ti alloy superconducting materials are: large cyclotron high-energy accelerators with a diameter of more than 1 km and magnetic resonance imaging diagnostic instruments widely used in the medical sector.

Although in the mid-1980s, scientists discovered a copper oxide high-temperature superconductor that can operate at liquid nitrogen temperature (77K); Cost and decades of experience in research, production and application development, niobium-titanium alloy is still the most important practical superconducting material in the world today.

The composition of the niobium-titanium superconducting alloy material should meet the requirements of Tc, Hc2 and Jc as high as possible, generally in the range of Nb-(40%-55%)Ti.

This alloy composition can not only obtain appropriately high Tc and Hc2, but also produce superconducting materials with high current-carrying capacity and a large number of precipitated phases.

There are 6 grades of niobium-titanium alloy superconducting materials used internationally:
Nb-44Ti, Nb-46.5Ti, Nb-48Ti, Nb-50Ti, Nb-53Ti, Nb-55Ti, etc., among which Nb-46.5Ti and Nb-50Ti are widely used grades of alloy components.

Application of niobium-titanium superconducting alloy
Niobium-titanium alloy superconducting materials have been used in large-scale devices such as superconducting high-energy accelerators, superconducting nuclear magnetic resonance imaging diagnostic instruments, superconducting maglev high-speed trains, and superconducting strong magnetic separators;
It is also used in energy development such as controlled nuclear fusion, magnetic fluid power generation, generators, power transmission, and energy storage.

In addition, it is used in strong magnetic propulsion systems (ships, ships, high-speed launching devices, etc.) and military defense.

In short, the plastic niobium-titanium alloy superconducting material plays an important role in large-scale superconducting application devices, and it is the most used (>95%) superconducting material in the world.

superconductor NbTi alloy rod

 Nb-50% Ti-50% Introduction

Nb-50% Ti-50% has good superconductivity and is used in superconducting industry. It is also very strong, so it is also used in aerospace industry.

 Nb-50% Ti-50% is an alloy consists of niobium andtitanium. Normally the content of titanium is between 20% and 60% for industrial-used niobium titanium alloys. The most typical niobium titanium alloy is approximately titanium 66%.

 Niobium titanium alloy is an important alloyed superconductor material. Its superconductive transition temperature is 8K to 10K. If other elements are added into the alloy, superconductivity will be improved.

 Niobium titanium alloy is sintered by alloyed powder. We use vacuum electrode arc furnace or electron-beam furnace to melt the alloyed ingots. The niobium titanium alloys can be in various forms sheet, bar, wire, target.