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By Trunnano | 26 September 2022 | 0 Comments

Silicon nitride ceramic

Silicon nitride is considered to be a very important engineering ceramic because it is suitable for many different forms, each of which has unique characteristics. At high temperature, silicon nitride shows excellent mechanical properties, including low density, high bending strength, high elastic modulus and fracture toughness, high wear and resistance to solid particles. In other words, this material is very strong, very tough. The material also shows excellent thermal properties with minimal expansion and shrinkage caused by temperature and is able to withstand thermal shock (rapid and significant temperature changes). Finally, silicon nitride has excellent chemical properties, including stability to most acids and bases, corrosive gases and liquid metals.
 
Rolling contact fatigue (RCF) tests of several ceramic-based materials bearing high-performance bearing loads show that only completely dense silicon nitride can outperform bearing steel. The fully dense Si3N4 bearing material shows that the service life of RCF is ten times longer than that of high performance bearing steel. A high-speed rotating body may lead to significant centrifugal stress. As a low-density material, silicon nitride is as light as aluminum. However, this property also brings another benefit to the material. The low density of silicon nitride reduces the centrifugal stress on the high-speed rotating outer ring. The high tensile strength of silicon nitride ceramics can resist elongation and provide excellent bending strength to withstand yield or fracture under increased transverse stress. Fully dense Si3N4 also shows high fracture toughness and high modulus, which makes the material have excellent resistance to a variety of wear phenomena. This enables it to withstand harsh operating conditions that may lead to cracks, deformation or collapse of other ceramic materials.
 
In addition to excellent mechanical properties, silicon nitride also exhibits a range of excellent thermal properties, making it suitable for demanding industrial applications. Thermal conductivity is the inherent ability of a material to transfer or conduct heat. Heat transfer coefficient is a key factor to characterize the applicability of engineering materials for any industrial application under extreme temperature requirements. Because of its unique chemical composition and microstructure, silicon nitride has the same low thermal conductivity as metal.
 
These properties enable silicon nitride to significantly reduce the thermal conductivity in extreme temperature applications. Thermal expansion is another problem that occurs when materials are heated and their size and volume increase in small increments. This expansion depends on the material being heated. The degree of expansion of the material with each increase of 1 °C is expressed by the ratio of its thermal expansion coefficient. The strong atomic bond of silicon nitride makes this material have a low coefficient of thermal expansion, which makes its deformation value with temperature very low.
 
Compared with other ceramics, the radio frequency (RF) characteristics of silicon nitride will not be greatly affected in high-speed applications because of its excellent thermal quality. Silicon nitride is the material of choice for a variety of radio frequency applications because of its moderate dielectric constant (the ability of a substance to store electrical energy in an electric field) and low radio frequency loss, as well as excellent strength and heat resistance.
 
It is the unique combination of characteristics of silicon nitride that leads to further research on its use as structural ceramics in biomedical applications. The biocompatibility of silicon nitride was established as early as the late 1980s, which was confirmed by initial in vitro studies and subsequent studies involving implanting silicon nitride into animals. A 1999 study further supported the claim of silicon nitride for the biocompatibility of functional human osteocyte proliferation in vivo (in vitro). These findings further promote silicon nitride as a new biomedical material. In addition to its biocompatibility, silicon nitride is known to have surface chemical properties that facilitate bone formation (osteogenesis) and increase bone contact with implants.
 
Silicon nitride has excellent stability because of its strong atomic bond, which makes the material resistant to corrosion in acidic and alkaline solutions at room temperature. This is crucial when considering long-term implantation in a watery and salty environment. The corrosion resistance is mainly attributed to the formation of oxide layer on the surface of the material. The same resistance was observed when silicon nitride was placed in hot gases, molten salts and metals and corrosion tests were carried out in complex environments. The formation of oxide layer plays a core and complex role in the corrosion resistance of materials.
 
Because of its self-reinforced microstructure, high strength and toughness and many excellent properties, silicon nitride has become an attractive structural component for many applications in various industries, including biomedical applications.
 
Silicon nitride Price
The price is influenced by many factors including the supply and demand in the market, industry trends, economic activity, market sentiment, and unexpected events.
If you are looking for the latest Silicon nitride powder price, you can send us your inquiry for a quote. ([email protected])
 
Silicon nitride Supplier
Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) is a trusted Si3N4 manufacturer and Si3N4 supplier with over 12-year-experience. We ship our goods all over the world.
 
If you are looking for high-quality Si3N4 powder, please feel free to contact us and send an inquiry. ([email protected])

 

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