Silicon nitride products can reduce transition metal (see transition elements) oxides, lead oxide, zinc oxide and tin dioxide above 600 ℃, and release nitrogen oxide and nitrogen dioxide. At 1285 ℃, silicon nitride reacts with tricalcium dinitride Ca3N2 as follows: the preparation methods of Ca3N2 + Si3N4 - → 3casin2 silicon nitride are as follows: the powdered silicon reacts with nitrogen at 1300 ~ 1400 ℃; Pure silicon reacts with ammonia at 1500 ℃; Burning a mixture of silica and carbon in nitrogen containing a small amount of hydrogen; The ammonolysis product Si (NH2) 4 of SiCl4 was completely thermally decomposed. Silicon nitride can be used as catalyst carrier, high temperature resistant material, coating and abrasive. Silicon nitride product ceramics have the characteristics of high strength and high temperature resistance. Among ceramic materials, its comprehensive mechanical properties are the best, with good heat shock resistance, oxidation resistance, wear resistance and corrosion resistance. It is the first candidate material for ceramics for thermal engine parts. In the mechanical industry, silicon nitride ceramics are used as bearing balls, rollers, ball races, tools and molds, new ceramic cutting tools, pump plungers, spindle sealing materials, etc.

 

 

 

In the chemical industry, silicon nitride ceramics are used as wear-resistant and corrosion-resistant parts. Such as ball valve, pump body, combustion carburetor, filter, etc. In the metallurgical industry, silicon nitride ceramics have high temperature resistance, low friction coefficient and self-lubricating. The solution of most metals and alloys is stable. Therefore, tools and molds for metal material processing can be made, such as mandrel, extrusion and wire drawing molds, rollers, transfer rollers, heater fixture, thermocouple sleeve, metal heat treatment support, crucible, aluminum liquid guide, aluminum package lining, etc. Silicon nitride products and ceramic materials are also widely used in electronics, military and nuclear industries.