Superconducting materials and superconducting technologies have broad application prospects. The meissner effect in the phenomenon of superconductivity allows people to make superconducting trains and ships using this principle, as these vehicles will operate in a state of suspension without friction, which will greatly improve their speed and quietness and effectively reduce mechanical wear. Superconducting suspension can be used to manufacture wear - free bearings, which can increase the speed of bearings to more than 100,000 revolutions per minute.
Superconducting trains, which successfully tested the feasibility of carrying passengers in the 1970s, began trial operations in Japan in 1987, but often failed, possibly due to bumps caused by high-speed travel. The superconducting ship was launched for trial on January 27, 1992 and has not yet entered the practical stage. Using superconducting materials to make transportation tools still has some technical obstacles, but it is bound to cause a wave of transportation vehicle revolution.
The zero-resistance properties of superconducting materials can be used to transmit electricity and make large magnets. The use of superconductors can reduce the loss to the maximum extent, but the use of superconductors with higher critical temperature has not yet entered the practical stage, which limits the use of superconducting transmission. With the development of technology and the emergence of new superconducting materials, the hope of superconducting transmission will be realized in the near future.
The existing high-temperature superconductor is still in a state where liquid nitrogen must be used to cool it, but it is still considered one of the greatest discoveries of the 20th century.
According to its chemical composition, superconducting materials can be divided into elemental materials, alloy materials, compound materials and superconducting ceramics. Superconducting elements: 28 elements have super conductivity under atmospheric pressure, of which niobium (Nb) has the highest Tc, 9.26k. The practical application in electrical engineering is mainly niobium and lead (Pb, Tc= 7.201k), which have been used in the manufacture of superconducting alternating power cables, high-q resonator and so on. Diamond alloy material: superconducting elements add some other elements as alloy components, which can improve all the properties of superconducting materials. For example, niobium zirconium alloy (nb-75zr), which was first applied, has a Tc of 10.8k and a Hc of 8.7 specie. Niobium and titanium alloys have since been developed, although Tc is slightly lower, Hc is much higher and can carry more current in a given magnetic field. Its performance is nb-33ti, Tc=9.3K, Hc=11.0 t; Nb-60ti, Tc=9.3K, Hc=12 ter (4.2K). Nowadays niobium titanium alloy is the main superconducting magnet material used in 7 ~ 8 special magnetic fields. The performance of nb-60ti-4ta was further improved by adding tantalum into niobium titanium alloy. The performance of nb-60ti-4ta was Tc= 9.9k, Hc= 12.4t (4.2k). The performance of nb-70ti-5ta is Tc=9.8K, Hc=12.8 t. HTS: superconducting elements combine with other elements and have good superconducting properties. If Nb3Sn has been used extensively, its Tc= 18.1k, Hc=24.5 special. Other important superconducting compounds are V3Ga, Tc=16.8K, Hc=24 t. Nb3Al, Tc=18.8K, Hc=30 t. Hering superconducting ceramics: in the early 1980s, miller and bednold began to notice that some oxide ceramic materials might have superconductivity. Their team tested some materials and found Tc=35K in lanthanium-ba-cu-oxide in 1986. In 1987, scientists from China, the United States, Japan and other countries found that Tc had superconductivity in the liquid nitrogen temperature zone, making superconducting ceramics a promising superconducting material.
