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 in high-speed and high-temperature environments where steel bearings would fail. Its low thermal expansion and high hardness make it ideal for cutting tools, enabling efficient machining of hard metals with extended tool life.

In the automotive and aerospace industries, silicon nitride components are used in turbochargers, improving efficiency and durability under extreme temperatures. It is also employed in gas turbines and heat engines as a structural ceramic component, offering better performance at elevated temperatures compared to metals.

In electronics, silicon nitride serves as a passivation and insulating layer in microchips and semiconductor devices, protecting circuits from moisture and contaminants. It acts as a diffusion barrier and is used in thin-film form during integrated circuit fabrication.

Additionally, silicon nitride is used in medical applications such as bone implants due to its biocompatibility and wear resistance. Its ability to withstand repeated stress and corrosion makes it suitable for long-term implantable devices.