What are Silicon Nitride Properties?

If you are looking for high-quality products, please feel free to contact us and send an inquiry, email: brad@ihpa.net



Silicon nitride can be considered an essential engineering clay. High temperatures give silicon nitride excellent mechanical properties. These include low density and high bending strength. They also have high fracture toughness. The material has excellent thermal characteristics, can withstand rapid, significant temperature changes and minimizes expansion and contraction. The chemical properties of silicon nitride are excellent, with good stability to most acids, bases, corrosive gases and liquid metals.
The results of rolling contact fatigue (RCF), tests on various ceramic-based materials that were subjected to high performance bearing loads have shown that only fully dense silicon nitride is capable of outperforming bearing steel. RCF has a ten-fold longer service life than high-performance steel bearings, thanks to its compact Si3N4 bearing. A high-speed rotating body may cause significant centrifugal stresses. Because it is a low-density metal, silicon nitride can be as light as aluminium. This material has an additional benefit. The low density Si3N4 helps to reduce the centrifugal stresses on the outer rings of the high speed rotating body. The high tensile strength and flexibility of silicon-nitride ceramics allows for resistance to elongation as well as excellent flexural strength that can withstand rupture or yield under higher lateral stresses. The full density Si3N4 is also extremely resistant to fracture toughness and modulus. This material can withstand severe operating conditions that could cause other ceramic materials such as cracking, deformation or collapse.

It is capable of displaying superior mechanical properties and thermal properties. This makes silicon nitride suitable for demanding industrial applications. Thermal conductivity refers to the material’s ability to conduct or transfer heat. The heat transfer coefficient plays a critical role in determining the suitability for industrial applications. Silicon nitride, due to its unique chemical structure and microstructure, has the same low thermal conductivity of metals.

These properties enable silicon-nitride’s ability to significantly lower thermal conductivity in extreme temperatures. The thermal expansion problem occurs when materials heat up and their volume and size change in small increments. This expansion is dependent on the temperature of the material. The ratio of thermal expansion coefficients is a measure of the material’s expansion per 1degC temperature increase. Because of the strong atomic bonds of Si3N4, this material has a low coefficient thermal expansion. It also experiences very little deformation when heated.

The superior thermal properties of silicon nitride make it less sensitive to high-speed applications. Silicon nitride, which has a moderate dielectric constant (the capacity of a substance or material to store electric energy in an electrical field), is preferred for many RF applications. It also has excellent strength and heat resistance.

This unique combination of properties has led to further research on silicon nitride’s use in structural ceramics for biomedical applications. In vitro and in vivo studies, as well as later studies involving the injection of silicon dioxide into animals, have established the biocompatibility. An in vitro study from 1999 further confirmed the biocompatibility claim of Si3N4 for functional human bone cell proliferation. These findings support silicon nitride being a promising biomedical material. Additionally to its biocompatibility silicon nitride has surface chemical characteristics that encourage bone formation (osteogenesis), as well as increased bone contact with implants.

Silicon nitride exhibits excellent stability because of its strong Atomic Bonds. This material is highly resistant to corrosion in acidic and alkaline environments at room temperatures. This is important when implanting silicon nitride in a humid and salty environment. This is due to the formation on the material of an oxide layer. When silicon nitride was subject to heat gases, molten metals, or other chemicals, the same resistance was observed. This is how materials resist corrosion.

Its unique microstructure that self-reinforces, its high strength, toughness and other excellent properties make silicon nitride a desirable structural component for many applications across a range of industries, including biomedical.

Technology Co. Ltd. is a trusted global supplier of chemical materials and manufacturer. With over 12-years experience in producing super high-quality chemicals & nanomaterials such as silicon powder (nitride powder), graphite dust, zinc sulfide, calcium nitride and 3D printing material, etc.
Send us an inquiry if you’re looking for high-quality siN powder. (brad@ihpa.net)