Preparation history of silicon nitride

The synthetic method of silicon nitride was first reported by Henry Aiding St. Claire De Ville and Friedrich W?hler in 1857. In the synthesis method reported by them, another crucible filled with silicon is buried in a crucible filled with carbon and heated to reduce the penetration of oxygen. They reported a product they called silicon nitride, but they failed to find out its chemical composition. 1879 Paul Schuetzenberger obtained this product by mixing silicon with a lining (a paste that can be used as a crucible lining and is obtained by mixing charcoal, coal lump or coke with clay) and heating it in a blast furnace, and reported that it is a compound with Si3N4 composition. In 19 10, Ludwig Weiss and teodor engelhardt heated silicon in pure nitrogen to obtain Si3N4. 1925, Friederich and Sittig used carbothermal reduction method to heat silicon dioxide and carbon to1250-1300 c in nitrogen atmosphere to synthesize silicon nitride.

In the following decades, silicon nitride has not been concerned and studied until the commercial use of silicon nitride appeared. During the period from 1948 to 1952, Acheson founded emery Company near Niagara Falls in new york, and registered a number of patents for the manufacture and use of silicon nitride. 1958 silicon nitride produced by Union Carbide Company is used to manufacture thermocouple tubes, rocket nozzles and crucibles for melting metals. The research on silicon nitride in Britain began in 1953, with the aim of manufacturing high-temperature components of gas turbines. Therefore, bonded silicon nitride and hot pressed silicon nitride have been developed. 197 1 year, the defense advanced research projects agency under the U.S. Department of Defense signed a contract with Ford and Westinghouse worth17 million dollars to develop two kinds of ceramic gas turbines.

Although the characteristics of silicon nitride have long been widely known, silicon nitride (about 2×5? M) was found in meteorites in the 1990s. In memory of Alfred Otto Karl Neil, the pioneer of mass spectrometry research, this silicon nitride ore found in nature was named "nickel iron ore". However, there is evidence that this kind of silicon nitride ore existing in meteorites may have been discovered earlier in Azerbaijan of the former Soviet Union. . Meteorites containing silicon nitride minerals have also been found in Guizhou Province, China. In addition to meteorites on earth, silicon nitride is also distributed in cosmic dust in outer space.