Silicon Nitride (Si3N4) is a high melting point ceramic material with extremely high hardness and chemical inertness. Hot-pressed silicon nitride, in particular, is one of the hardest substances in the world.Silicon nitride ceramics have low thermal expansion coefficient and high thermal conductivity, so their thermal shock resistance is excellent. Silicon nitride has high strength and impact resistance at not too high temperatures. However, when used above 1200 ℃, it will be damaged with the increase of use time, and its strength will decrease.
