Silicon nitride is widely used in high-performance engineering applications due to its exceptional thermal, mechanical, and chemical stability. It is a key material in manufacturing ceramic bearings and bearing balls, especially for high-speed and high-temperature environments where steel bearings would fail. Its low thermal expansion and high fracture toughness make it ideal for use in automotive and aerospace components, such as turbocharger rotors and engine parts, improving efficiency and durability.

In the electronics industry, silicon nitride serves as a passivation and insulating layer in integrated circuits, protecting devices from moisture and mechanical damage. It is also used as a diffusion barrier and etch mask in semiconductor fabrication processes.

Another major application is in cutting tools, where silicon nitride-based ceramics enable high-speed machining of cast iron and other hard materials with superior wear resistance and thermal shock resistance.

Additionally, it is used in medical applications, such as bone implants, due to its biocompatibility and wear resistance. In renewable energy, silicon nitride is being explored for use in advanced solar cells and energy storage systems because of its dielectric properties and structural stability.