Silicon Nitride in Automotive Applications

Ceramics are used in many industrial applications, including the automotive industry1. These materials are found in engine parts and engine accessory units, including turbochargers for lower inertia and reduced engine lag and emissions, glow plugs for faster startup, exhaust gas control valves for increased acceleration, and rocker arm pads for gas engines to lower wear2.

Regulatory restrictions on engine emissions and higher fuel costs have driven the use of silicon nitride in the automotive industry3. Each application within the automotive industry requires subtly different, yet tightly controlled attributes, to be able to meet specific requirements and attain the greatest improvement in performance versus other materials.

Light and Wear Resistant

Owing to its excellent thermal shock resistance compared to other ceramics, silicon nitride is a very useful material for the fabrication of high-performance all-ceramic or hybrid steel-ceramic rolling contact bearings4. The material’s extreme strength, toughness, and resistance to chemical and thermal factors offers significant benefits by extending contact fatigue life.

As a low-density material, silicon nitride can greatly reduce the dynamic loading during ball contacts in very high-speed applications such as those in gas turbine engines. The material also has notable applications in severe lubrication and wear conditions including extreme temperature, large temperature differential, and ultra-high vacuum, as well as in safety-critical applications.


1. Akira Okada, “Ceramic technologies for automotive industry: Current status and perspectives”, Materials Science and Engineering:B, Volume 161, Issues 1–3, 15 April 2009, Pages 182-187.


3. Bright, E., Eckalbar, J., McEntire, B., Pujari, V. et al., “Advanced Ceramic Manufacturing of SiALON Exhaust Valves,” SAE Technical Paper 960051, 1996

4. L. Wanga, R.W. Snidle, L. Gua, “Rolling contact silicon nitride bearing technology: a review of recent research”, Wear, Volume 246, Issues 1–2, November 2000, Pages 159-173

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