Silicon nitride still has many uses in life. The chemical formula of silicon nitride is Si3N4. Its raw material is silicon powder. The silicon powder is first made into the shape you want, and then in nitrogen at a high temperature of 1200 degrees Celsius. The silicon powder is nitrided, and it already has a certain degree of toughness. Then the silicon powder is nitrided for the second time at a higher temperature. The strength of the silicon nitride obtained is very high, at 1900 degrees Celsius. It will decompose at high temperatures, has no melting point, good thermal conductivity and small thermal expansion coefficient.
It can be used to make glow plugs due to its electrical insulation and rapid cooling and heating properties. Silicon nitride is also wear-resistant, corrosion-resistant, and not easily oxidized, so it has been used to make metal cutting tools.
Using the insulation and corrosion resistance of silicon nitride, it can also be used to make heat shields and magnetic rings, mainly used to protect high-voltage electrodes. This kind of protective cover lasts a long time and will not receive electric shock during use. impact, to some extent reducing the damage caused by natural factors.
Silicon nitride has a small friction coefficient and its own lubricity, so it is also used in the field of mechanical engineering. Its hardness is high, second only to diamond, so it is also used in the field of ultra-fine grinding.
Because silicon nitride can also withstand the impact of alternating hot and cold, it is light in weight and strong, so people also take advantage of this feature to make rolling bearings. Because this kind of bearing is harder than metal, it reduces the friction with the bearing track. Contact, usually this kind of bearing can be seen on bicycles and skates.
