Scandium is a chemical element, the element symbol is Sc, and the atomic number is 21. The simple substance is a soft, silver-white transition metal, often mixed with gadolinium, erbium, etc., and the output is very small, the content in the earth's crust is about 0.0005%. Scandium is often used to make special glass and lightweight high-temperature alloys.
What's more interesting is that the uses of scandium (as the main working substance, not for doping) are concentrated in a very bright direction, and it is not an exaggeration to call him the son of light.
The elemental form of scandium has been widely used in the doping of aluminum alloys. As long as a few thousandths of scandium is added to aluminum, a new phase of Al3Sc will be formed, which will change the structure and properties of the aluminum alloy. Adding 0.2%~0.4% Sc (this proportion is really similar to the proportion of salt in the cooking at home, only a little bit) can increase the recrystallization temperature of the alloy by 150~200℃, and the high temperature strength, structural stability, and welding Both performance and corrosion resistance are significantly improved, and the embrittlement phenomenon that is easy to occur during long-term work at high temperature can be avoided. High-strength and high-toughness aluminum alloys, new high-strength corrosion-resistant weldable aluminum alloys, new high-temperature aluminum alloys, high-strength aluminum alloys for neutron radiation resistance, etc., are used in aerospace, aviation, ships, nuclear reactors, light vehicles and high-speed trains, etc. Very attractive development prospects
Elemental scandium is generally used in alloys, and the oxide of scandium also plays an important role on ceramic materials as a kind of aggregation.
In chemistry and chemical industry, scandium is often used as a catalyst. Sc2O3 can be used for the dehydration and deoxygenation of ethanol or isopropanol, the decomposition of acetic acid, the production of ethylene from CO and H2, and so on. The Pt-Al catalyst containing Sc2O3 is used as an important catalyst in the hydrogenation purification and refining process of heavy oil in petrochemical industry. In the catalytic cracking reaction of cumene, the Sc-Y zeolite catalyst is 1000 times more active than aluminum silicate. Compared with some traditional catalysts, the development prospects of scandium catalysts will be very bright. 
Nuclear Energy Industry
Adding a small amount of Sc2O3 to UO2 in the nuclear fuel of high-temperature reactors can avoid the transformation of UO2 to U3O8, the increase in volume and the appearance of cracks.
The fuel cell
Similarly, adding 2.5% to 25% scandium in a nickel-alkali battery will increase the service life.
In agriculture, the seeds of corn, beet, peas, wheat, sunflower, etc. can be treated with scandium sulfate (concentration is generally 10-3~10-8mol/L, different plants will be different), and the actual effect of promoting germination has been achieved. Compared with the dry weight of buds and seedlings, they increased by 37% and 78%, respectively, but the mechanism is still under study.