1. Bearings and ball bearings: Silicon nitride ceramic bearings and ball bearings are widely used in high-speed machine tools, wind turbines, and aerospace equipment due to their high hardness, low friction coefficient, and wear resistance.

2. Seals and valves: In the chemical and petroleum industries, silicon nitride ceramic seals and valve fittings can withstand corrosive media and high temperature environments, extending equipment service life.

3. Silicon nitride ceramics are used as corrosion-resistant materials in chemical reactors and pipelines, capable of withstanding strong acids, strong alkalis, and high temperature environments.

4. Cutting tools: Silicon nitride ceramic cutting tools perform well in high-speed cutting and hard material processing, providing high precision and long life.