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 ceramic bearings, 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 components in automotive engines, such as turbocharger rotors and glow plugs, improving efficiency and durability.

In the manufacturing industry, silicon nitride is used in cutting tools for machining hard metals, offering longer tool life and faster cutting speeds compared to traditional materials. It is also employed in metal forming processes, such as rolls and guides in aluminum extrusion, where resistance to wear and thermal shock is critical.

In electronics, silicon nitride serves as a passivation and insulating layer in integrated circuits due to its excellent dielectric properties and ability to act as a diffusion barrier. It is also used in MEMS (micro-electromechanical systems) devices and as a protective coating in solar cells.

Additionally, silicon nitride finds use in biomedical applications, such as spinal implants, where its biocompatibility, wear resistance, and fracture toughness offer advantages over traditional implant materials.