Niobium is a metal element. The chemical symbol Nb, atomic number 41, atomic weight 92.90638, belongs to the periodic system VB. In 1801, British C. Hatchert separated the oxide of a new element from the coltan, and named it as columbium (Chinese translation). Rhodium is an off-white metal with a melting point of 2468 ° C, a boiling point of 4742 ° C and a density of 8.57 g/cm 3 . Rhodium is a shiny gray metal with paramagnetic properties and belongs to the 5th group of the periodic table. High-purity base metals have higher ductility, but harden as the content of impurities increases. The capture cross section for thermal neutrons is very low, so it is quite useful in the nuclear industry.
It is important to know that ultra-low temperatures are not easy to obtain, and people pay a huge price for this; the more they approach absolute zero, the more they will cost. So our requirements for superconducting materials, of course, the higher the critical temperature, the better.
There are many elements with superconducting properties, and helium is one of the highest critical temperatures. The alloys made of tantalum, the critical temperature up to an absolute temperature of 18.5 to 21 degrees, are currently the most important superconducting materials.
People have done such an experiment: put a metal ring that is cold to superconducting state, put current and then disconnect the current, and then close the whole instrument to keep it cool. After two and a half years, people turned the instrument on and found that the current in the ankle ring was still flowing, and the current intensity was almost exactly the same as when it was energized!
It can be seen from this experiment that the superconducting material hardly loses current. If you use a superconducting cable to transmit power, because it has no resistance, there will be no energy loss when the current passes, so the transmission efficiency will be greatly improved.
A high-speed maglev train has been designed with superconducting magnets mounted on its wheels so that the entire train can float about ten centimeters in orbit. In this way, there will be no friction between the train and the track, reducing the resistance to advance. A row of 100-person maglev trains can reach speeds of more than 500 kilometers per hour with a driving force of 100 horsepower.
Wrapped around a ferrule of up to 20 kilometers, wound around a rim of 1.5 meters in diameter, the windings produce a strong and stable magnetic field, enough to lift a weight of 122 kilograms and make it Suspended in the magnetic field space. If this kind of magnetic field is used in the thermonuclear fusion reaction and the powerful thermonuclear fusion reaction is controlled, it is possible to provide us with a large amount of almost endless cheap electricity.
Not long ago, a DC generator was made from a titanium-titanium superconducting material. It has many advantages, such as small size, light weight, and low cost. Compared with ordinary generators of the same size, it generates a hundred times more electricity.
Why Niobium have such a strange effect in surgery?
The key is because it has excellent corrosion resistance, does not interact with various liquid substances in the human body, and almost does not damage the organism's body tissues. It can adapt to any sterilization method, so it can be combined with organic tissues for a long time. And stay in the human body harmlessly.
In addition to such good use in surgery, they can also be used to make electrolytic capacitors, rectifiers, etc., using the chemical stability of niobium and Ta.
Among the various microalloying elements of steel, waste bismuth is the most effective microalloying element. The effect of bismuth is so great that the iron atom is rich in strontium atoms, which can improve the performance of steel. In fact, the addition of 0.001% to 0.1% bismuth in the steel is enough to change the mechanical properties of the steel. For example, when 0.1% of alloying elements are added, the yield strength of the steel is increased as follows: niobium 118 MPa; vanadium 71.5 MPa; molybdenum 40 MPa; manganese 17.6 MPa; titanium is zero. In fact, only 0.03%-0.05% Nb is added to the steel, and the yield strength of the steel can be increased by more than 30%. The cost of steel is only $1 per ton. For example, the yield strength of ordinary medium carbon steel is generally 250 MPa, and the addition of trace amounts of strontium can increase the strength to 350-800 MPa.
Niobium can also achieve the distribution of precipitates by inducing precipitation and controlling the cooling rate. Adjust the toughness level of the steel over a wide range. Therefore, the addition of niobium can not only improve the strength of steel, but also improve the toughness, high temperature oxidation resistance and corrosion resistance of steel! Reduce the brittle transition temperature of steel, and obtain good welding performance and molding performance.