Silicon Nitride vs. Boron Nitride Ceramic Shafts: A Comprehensive Comparison and Applications Overview

In the vast field of advanced materials, silicon nitride and boron nitride (BN) ceramic shafts are emerging as representatives of high performance and are widely used in many industries with demanding material properties. With their unique physicochemical properties, they play a key role in their respective application scenarios.

boron nitride (BN) ceramic shafts


Comparison of the characteristics of Silicon Nitride and Boron Nitride Ceramic Shafts

Mechanical Properties


Silicon nitride ceramic shafts are known for their high strength and hardness, which can reach a hardness of HV1200 or more (Vickers hardness), a bending strength of 800 – 1000MPa, and a compressive strength of 600MPa or more. This makes it perform well under high loads and high stresses and can effectively resist wear and deformation, suitable for heavy-duty mechanical components. For example, in some key rotating parts of automotive engines, silicon nitride ceramic shafts can operate stably and ensure efficient engine operation.


The mechanical properties of boron nitride ceramic shafts are different. Hexagonal boron nitride ceramic hardness is low, and Mohs hardness is only 2, which makes it easy to carry out mechanical processing and can be made into a variety of complex shapes of ceramic products. However, its strength and modulus of elasticity are relatively low, and it withstands higher loads than the silicon nitride ceramic shaft. However, some of the hardness requirements are not high, but the material processability and self-lubricating needs of the occasion, boron nitride ceramic shafts show unique advantages.


Thermal Performance


From the point of view of thermal stability, silicon nitride ceramic shafts can maintain good performance in high-temperature environments; its oxidation temperature can be as high as 1400 ℃, in the dry oxidizing atmosphere below 1400 ℃ can remain stable, the use of the temperature is generally up to 1300 ℃ and can be applied even to 1800 ℃ in a neutral or reducing atmosphere. Moreover, silicon nitride has a low coefficient of thermal expansion, good dimensional stability in temperature change, and can effectively avoid material rupture due to thermal stress, which is widely used in high-temperature furnaces, heat exchangers and other equipment.


Boron nitride ceramic shaft also has excellent high-temperature resistance; in the oxidation atmosphere of 900 ℃, a nitrogen atmosphere of 2800 ℃ can be used. Its thermal conductivity is high, and hot-pressing boron nitride ceramics have excellent thermal shock resistance and can be used for rapid cooling and heating environments of the structural components. However, under vacuum conditions, boron nitride ceramics are prone to decomposition, which, to some extent, limits its application in some special environments.


Chemical stability


Silicon nitride ceramic axis of good chemical stability, in addition to hydrofluoric acid, does not react with other inorganic acids; a variety of non-ferrous metal solutions, especially aluminum solution, do not wet, can withstand strong radiation, in the chemical industry, metallurgy, and other corrosive environments have good applicability.


Boron nitride ceramic shafts in chemical stability also have a good performance, just compared to its corrosion resistance is slightly inferior in some strong corrosive environments and is not as resistant as silicon nitride ceramic shafts.

Silicon nitride ceramic shafts


Comparison of Silicon Nitride and Boron Nitride Ceramic Shafts Specification Sheets

ItemSilicon Nitride (Si₃N₄) Ceramic ShaftBoron Nitride (BN) Ceramic Shaft
Hardness≥ HV1200 (Vickers hardness)Hexagonal BN: Mohs hardness 2
Flexural Strength800–1000 MPaRelatively lower
Compressive Strength≥ 600 MPaRelatively lower
Maximum Service TemperatureOxidizing atmosphere: 1300°C
Neutral/reducing atmosphere: 1800°C
Oxidizing atmosphere: 900°C
Nitrogen atmosphere: 2800°C
Thermal Expansion CoefficientLowSlightly higher than silicon nitride
Chemical StabilityResistant to most acids, alkalis, and metal corrosion (except hydrofluoric acid)Good resistance but relatively weaker than silicon nitride
MachinabilityRelatively difficult to machineEasy to machine (suitable for complex shapes)
Maximum DimensionsLength ≤ 1200 mm
Diameter ≤ 300 mm
Thickness ≤ 50 mm
Varies by processing technology and equipment

Comparison of Silicon Nitride and Boron Nitride Ceramic Shafts in applications


In the aerospace field, silicon nitride ceramic shafts are widely used in engine parts, thermal protection systems and other key components to ensure reliability under extreme conditions due to their high strength, high-temperature resistance and good dimensional stability. Boron nitride ceramic shafts, due to their low hardness, good processability and lubrication performance at high temperatures, can be used in parts that require high precision in shape and self-lubrication, such as some of the special rotating parts inside some aviation engines.


In the manufacture of electronic equipment, silicon nitride ceramic shafts can be used to manufacture insulators, substrates and other components, with good electrical insulation and thermal conductivity, to ensure that the equipment is in a high-power, high-temperature environment, safe and stable operation. Boron nitride ceramic shafts are commonly used in the production of heat-dissipation structures and insulated heat-dissipation substrates in electronic equipment due to their high thermal conductivity and good electrical insulation.

In the machinery industry, silicon nitride ceramic shafts are often used as key materials for cutting tools, grinding tools and wear-resistant parts due to their excellent wear resistance. Boron nitride ceramic shaft of self-lubricating properties in mechanical seals. High-temperature solid lubricants play an important role in the 100 – 1200 ℃ air, inert gas, and hydrogen environment; the use of performance is better than some other solid lubricants.

Supplier

RBOSCHCO is a trusted global chemical material supplier & manufacturer with over 12 years experience in providing super high-quality chemicals and Nanomaterials. The company export to many countries, such as USA, Canada, Europe, UAE, South Africa,Tanzania,Kenya,Egypt,Nigeria,Cameroon,Uganda,Turkey,Mexico,Azerbaijan,Belgium,Cyprus,Czech Republic, Brazil, Chile, Argentina, Dubai, Japan, Korea, Vietnam, Thailand, Malaysia, Indonesia, Australia,Germany, France, Italy, Portugal etc. As a leading nanotechnology development manufacturer, RBOSCHCO dominates the market. Our professional work team provides perfect solutions to help improve the efficiency of various industries, create value, and easily cope with various challenges. If you are looking for Silicon Nitride and Boron Nitride Ceramic Shafts, please send an email to: sales1@rboschco.com

Tags: Silicon Nitride,Boron Nitride Ceramic Shafts, Ceramic Shafts

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