What is the role of silicon nitride

What is the role of silicon nitride? Now, this is a little bit of an introduction to this maybe a lot of people don't understand it. Right?

Silicon nitride is an important structural ceramic material. It is a superhard substance, which is itself lubricity, and is resistant to wear and tear; it is an atomic crystal; High temperature resistance to oxidation. And it also can resist cold and hot shock, in air heated to above 1000 ℃, a sharp cooling heating sharply again, also won't fracture. It is because of silicon nitride ceramics with such excellent properties, people often use it to manufacture bearings, steam turbine blades, mechanical seal, mechanical components, such as permanent mould. If use high temperature resistant and not easily heat transfer of silicon nitride ceramic to make engine parts of heating surface, can not only improve the quality of diesel engine, save fuel, but also can improve the thermal efficiency. This kind of diesel has been developed in China, the United States and Japan.