Bismuth and its compounds have some special properties, making them widely used in electric light source, aerospace, electronics industry, nuclear technology, superconducting technology and so on. Table 1 lists some of the main uses of the current cockroaches. However, due to the scarcity of strontium-rich minerals, the separation and extraction of hydrazine is difficult, resulting in the high cost of strontium and its compounds, thus affecting its application. Table 1 Main application areas of bismuth Category é’ª é’ª ã€‰ purity> 99.9% High-efficiency multi-function laser; solid electrolyte; special ceramic Sc-Al intermediate alloy aluminum-magnesium-based alloy, the most effective improver; production of missiles and manufacturing spacecraft, automobiles, ships Special alloy metal é’ª purity>99.99% Optical engineeringâ€”high-power metal halide lamp, solar battery; nuclear energy shielding for high-energy radiation 1.1 New electric light source material and optical material é’ª as electric light source material, using cesium iodide (ScI3) and é’ªMetal halide lamp made of foil - sodium lamp, has already entered the commodity market. The lamp is a halide discharge lamp. Under high pressure discharge, the sodium and helium atoms in the NaI/ScI3 tube are excited, when they are from high energy level. When the excited state jumps back to the lower energy level, it emits light of a certain wavelength. The spectrum of sodium is 589~589.6nm yellow light, the spectrum of strontium is near ultraviolet and blue light of 361.3~424.7nm, and the two lines of strontium and sodium are just close to sunlight. Back to the ground state, the strontium and sodium atoms can be synthesized with iodide, so that the cycle can maintain a high atomic concentration in the lamp tube and prolong its service life. A sodium lamp with the same illumination is 80% more energy efficient than ordinary incandescent lamps, and its service life is 5000~25000hr. It is precisely because of the high luminous efficiency, good light color, power saving, long service life and strong ability to break fog, which makes it widely used in TV camera and wide-ranging gymnasium and road lighting. It is called the third generation. light source. The popularity of halogenated lamps in the United States has exceeded 50%, producing more than 10 million high-pressure sodium lamps per year, and more than 10 million products in Japan. The amount of antimony is more than 40Kg . Our country started late in this respect, but it has also implemented the â€œbig change of lightsâ€ plan. The development and popularity of global halogen lamps is expanding, and the demand for antimony will become more urgent. Adding Sc2O3 with a purity of 99.9~99.99% to yttrium gallium garnet (GGG) to obtain yttrium gallium garnet (GSGSS), the emission power of the latter is three times higher than the former. GSGG can be used in anti-missile defense systems, military communications, submarine water lasers, and industrial applications. The main applications are the United States and Japan. The secondary refractive index of the LiNbO3 crystal containing Sc2O3 is reduced, and is suitable for manufacturing a parameter frequency selector, a waveguide, and a photoconductive switch. The addition of yttrium to optical glass, silicate glass, and borosilicate improves the refractive index of the glass and improves the reflective properties. Barium fluoride glass can be used to fabricate optical fibers in the mid-infrared region of the spectrum. 1.2 The new niobium-containing alloy material has a very magical alloying effect on aluminum alloy. As long as a few thousandths of niobium is added to the aluminum, a new Al3Sc phase is formed, which acts as a metamorphism on the aluminum alloy, causing the structure and properties of the alloy to occur. obvious change. Adding 0.2%~0.4%Sc can increase the recrystallization temperature of the alloy by 150~200OC, and the high temperature strength, structural stability, weldability and corrosion resistance are obviously improved, and the embrittlement which is easy to occur during long-term work at high temperature can be avoided. phenomenon. Through the addition of trace amounts of bismuth, it is hoped that a series of new-generation aluminum alloy materials, such as ultra-high strength and high-toughness aluminum alloy, new high-strength corrosion-resistant weldable aluminum alloy, new high-temperature aluminum alloy, high-strength anti-intermediate, will be developed on the basis of existing aluminum alloys. Aluminum alloys for sub-irradiation, etc., have very attractive development prospects in aerospace, aviation, ships, nuclear reactors, light vehicles and high-speed trains. According to reports, the earliest and deepest research in this area in Russia has developed a series of excellent aluminum alloys, and is moving towards promotion and industrial production. The 1420 alloy has been widely used as a structural member for the MiG-29, MiG-26 aircraft, Tu-204 passenger aircraft and Jacques-36 vertical landing aircraft. The 1421 alloy is also used in the form of extruded profiles for the Antonov conveyor as a stringer for the fuselage. In addition, the United States, Japan, Germany and Canada, as well as China, South Korea, etc. have also begun research on niobium alloys. In recent years, the United States has used bismuth aluminum alloys for the manufacture of welding wire and sports equipment (such as baseball and softball bats, hockey sticks, bicycle beams, etc.). Baseball bats and softball bats made of bismuth alloy have been used in many world competitions and summer. Used in the Olympic Games. Since the melting point of ruthenium (1540 Â° C) is much higher than the melting point of aluminum (660 Â° C), the density of ruthenium (3.0 g / cm 2 ) is similar to the density of aluminum ( 2.7 g / cm 3 ), and it has been considered to use yttrium instead of aluminum as a rocket and Certain structural materials in the spacecraft. When studying the structural materials of spacecraft, the United States requires that the material should have high strength and corrosion stability at 920 Â° C, and the ratio is small. It is believed that niobium titanium alloy and niobium magnesium alloy have high melting point and small specific gravity. One of the ideal materials for high strength and other characteristics. Tantalum is also an excellent modifier for iron. A small amount of niobium can significantly increase the strength and hardness of cast iron. Tantalum can also be used as an additive for high temperature tungsten and chromium alloys. 1.3 Special ceramic bismuth oxide is much more expensive than other metal oxides with similar properties, so it is not very popular in ceramics. However, cerium oxide has special applications in some advanced ceramics due to its unique properties, the most prominent of which are as stabilizers for zirconia and compacting aids for silicon nitride and for the synthesis of specific ferroelectric ceramics. In addition, niobium can also be used to modify silicon carbide and aluminum nitride.
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