Common silicon nitride structural products, represented by silicon nitride (Si ∝ N ₄), have the following advantages and disadvantages:
advantage
In terms of mechanical properties
High hardness: Silicon nitride has a very high hardness, with a Mohs hardness of 9-9.5, only slightly lower than a few materials such as diamond and cubic boron nitride. It can be used to manufacture cutting tools, grinding tools, etc. It can maintain good cutting and grinding performance and is not easily worn out in long-term use.
High strength: It has high bending strength. Generally, the bending strength of hot pressed silicon nitride can reach 700-1000MPa, and the bending strength of reaction sintered silicon nitride can also reach 200-300MPa. It can withstand large external forces and loads and is suitable for manufacturing mechanical parts that can withstand high stress.
Low density: The density is about 3.1-3.2g/cm ³, which is similar to that of aluminum but much lower than many metal materials. When applied in aerospace, automotive and other fields, it can achieve lightweight design while ensuring strength, improving equipment efficiency and performance.
In terms of thermal performance
High temperature resistance: With a high melting point of about 1900 ℃, it can maintain good mechanical properties and chemical stability in high temperature environments, and can be used to manufacture components for high-temperature furnaces, combustion chambers for aircraft engines, etc.
Low thermal expansion coefficient: The thermal expansion coefficient is relatively small, about 2.7 × 10 ⁻⁶/℃. When the temperature changes sharply, the thermal stress generated inside the material is small, and it has good thermal shock resistance. It can maintain stable physical properties in rapid heating and cooling environments and is not easy to fracture.
High thermal conductivity: The thermal conductivity is relatively high, about 20-30W/(m · K), which can quickly conduct heat, making the temperature distribution of the material more uniform in high temperature environments and reducing local overheating.
In terms of chemical properties
Corrosion resistance: With good chemical stability, it has excellent corrosion resistance in most corrosive media such as acids, alkalis, and salts, and is not easily corroded or eroded. It can be used for components that come into contact with corrosive media in industries such as chemical and pharmaceutical.
Antioxidant properties: It can form a dense silicon oxide protective film on the surface at high temperatures, preventing further oxidation and possessing good antioxidant properties. It can be used for a long time in high-temperature oxidation environments.
In terms of electrical performance
Good insulation performance: It has good electrical insulation properties, high resistivity, low dielectric constant, and can be used to manufacture insulation components in electronic devices, substrates for integrated circuits, etc. It can effectively prevent current leakage and short circuits.
Microwave transmission performance: It has good transparency to microwaves and can be used to manufacture microwave devices such as radar antenna covers, without affecting the transmission and reception of microwaves.
disadvantage
In terms of preparation cost
High raw material cost: The synthesis of silicon nitride requires the use of high-purity silicon powder, nitrogen gas, and other raw materials, which have complex preparation and purification processes and high costs.
Complex process: The synthesis and processing of silicon nitride require complex process conditions such as high temperature and high pressure, such as hot pressing sintering, chemical vapor deposition, etc., which require high equipment requirements and high energy consumption during the production process, resulting in increased production costs.
In terms of mechanical properties
High brittleness: It is a typical brittle material that is prone to brittle fracture when subjected to external impact, with low mechanical impact resistance, which limits its application in some fields that require high impact resistance.
Low reliability: Due to its high brittleness, the reliability and stability of its products are relatively poor. During use, they may rupture due to minor defects or stress concentration, requiring strict control over the quality and usage environment of the products.
In terms of processing difficulty
High processing cost: The high hardness makes it difficult to process silicon nitride, requiring the use of special processing tools such as diamond cutting tools, and the processing efficiency is low, resulting in high processing costs.
Complex processing technology: Traditional processing methods are prone to serious tool wear, sample cracking, and other problems, requiring high requirements for processing technology and equipment. Advanced processing technologies such as electrical discharge machining and laser processing are needed, but the equipment investment and operating costs of these technologies are also high.  

Room termperature curing polysilazane, pls check IOTA 9150, IOTA 9150K.       
High termperature curing polysilazane, pls check IOTA 9108, IOTA 9118.