Silicon nitride

Silicon nitride (molecular formula Si3N4) is a kind of chemical compound comprised of both silicon and nitrogen elements. It appears as a white solid with a high melting point. It is chemically stable upon the presence of dilute HF and hot H2SO4. It has a series of properties such as high strength among a wide temperature range, high fracture toughness, high hardness, outstanding wear resistance and chemical property. It has a strikingly high thermal shock resistance. It has a wide applications in various kinds of fields. In automobile industry, it is an important materials for engine parts. It can also be applied to the manufacturing of bearings due to its high shock resistance. For example, in spacecraft, silicon nitride ceramic is capable of surviving the severe thermal shock generated in the hydrogen/oxygen rocket engines. It can also be used as abrasive and cutting tools due to its harness and resistance to wear. In electronics, it can be used as an insulator and chemical barrier during the production of integrated circuits. There are several method for the manufacturing the silicon nitride. 1. The powdered silicon is subject to a heating reaction of 1300-1400 °C in the atmosphere of nitrogen. 2 Diimide route which involves the reaction of SiCl and NH3. 3 Silicon dioxide is subject to carbothemral reduction at 1300-1400 °C under the presence of nitrogen.