Silicon Nitride—From Powder Synthesis to Ceramic Materials

Abstract Silicon nitride is a ceramic material of great interest to advanced engine construction and mechanical engineering owing to an outstanding combination of favorable properties like high mechanical strength at high temperatures, corrosion and wear resistance, great hardness, and low density. The material is based on high‐quality Si 3 N 4 powders, which are shaped and sintered to the ceramic component. This overview outlines the properties required for Si 3 N 4 powders suitable for advanced ceramics. Processes in commerical use and those under development for the production of high quality Si 3 N 4 powders are discussed as well as material manufacturing processes and material properties. By steadily improving powder quality, material properties, and the economy of powder and component production, chemistry and chemical technology play a major role in recent efforts to create a solid fundament for broad applications of silicon nitride ceramics. “If one would surrender to geological phantasies, one could imagine that during the formation of our planet, when elements combined to the compounds making up its crust and mountain ranges, silicon reacted with nitrogen, and the still red‐hot nitrogen‐silicon, on contact with water, may have decomposed to silicic acid and ammonia. Thus, ammonia may have been formed originally and nitrogen thereby introduced into the forming organic compounds when living nature first started to appear.” H. Sainte‐Claire Deville and F. Wöhler “Ueber die directe Bildung des Stickstoffsiliciums” in: Ann. Chem. Pharm. 34 (1859) 248: “If one would surrender to geological phantasies, one could imagine that during the formation of our planet, when elements combined to the compounds making up its crust and mountain ranges, silicon reacted with nitrogen, and the still red‐hot nitrogen‐silicon, on contact with water, may have decomposed to silicic acid and ammonia. Thus, ammonia may have been formed originally and nitrogen thereby introduced into the forming organic compounds when living nature first started to appear.”