Silicon Nitride (Si3N4) ceramic structural components are widely used in mechanical applications due to their exceptional performance. Combining high strength and excellent toughness, silicon nitride ceramics effectively resist impacts and the propagation of fatigue cracks. They also exhibit outstanding wear resistance, maintaining a long service life even in high-wear environments, making them suitable for components such as abrasives, pump shafts, and other high-wear mechanical parts.
Silicon nitride ceramics can maintain their mechanical properties at high temperatures, with a high melting point of approximately 1900°C, ensuring stability in elevated temperature environments. They possess excellent corrosion resistance against various acids, bases, and salts, along with low thermal conductivity, which helps reduce heat transfer and provides good insulation properties. Compared to other ceramic materials, silicon nitride ceramics have a lower density, contributing to the overall weight reduction of components. This makes them an ideal choice for applications requiring lightweight materials, such as critical components in the aerospace and automotive industries.
Preparation Process:
- Powder Preparation: Use high-purity silicon nitride powder and add sintering aids (e.g., alumina or yttria).
- Forming: Form using hot pressing or isostatic pressing.
- Sintering: Use atmosphere sintering or hot isostatic pressing to enhance density.
- Post-Processing: Conduct surface finishing or heat treatment.
Process Control: The density of silicon nitride is closely related to the sintering aids and conditions; sintering atmosphere, temperature, and pressure must be strictly controlled.
