Jul 11 , 2025
In ultra-high temperature, high-purity industrial furnaces such as semiconductor sintering furnaces, special ceramic sintering furnaces, and monocrystalline/polycrystalline silicon production furnaces, the selection of insulation materials is extremely critical. They must withstand extreme temperatures while ensuring material purity to avoid product contamination and achieve high energy efficiency.
1. Polycrystalline Alumina Fiber Blanket/Board: This is the core high-temperature insulation material. Due to its high purity (typically >99% alumina content) and extremely high service temperature (up to 1700°C), it effectively resists high-temperature shrinkage and chemical attack, making it ideal for furnace linings or critical hot-face applications.
2. High Purity Insulating Fire Bricks (IFB): Such as high-purity mullite bricks, alumina bubble bricks, or alumina hollow sphere bricks. They provide structural support and good insulation, typically serving as the second or third layer of the furnace lining.
3. Nanoporous Insulation Boards: Due to their extremely low thermal conductivity, they are often used as high-performance backup insulation layers, providing maximum insulation in limited space to further improve furnace energy efficiency.
4. Zirconia Fiber: Used for localized ultra-high temperature zones (above 1700°C) or extreme applications requiring resistance to specific types of corrosion.
5. Graphite Felt/Carbon Fiber Insulation: In non-oxidizing atmospheres or vacuum furnaces (like monocrystalline silicon growth furnaces), these carbon-based materials are ideal due to their ultra-high service temperatures and absence of oxide contamination.
6. High-Density Calcium Silicate Boards: Typically serve as the outermost insulation layer of the furnace body, providing good structural support and auxiliary insulation to control the outer shell temperature within safe limits.
When selecting these materials, besides temperature resistance, purity, thermal shock stability, creep resistance, and compatibility with the furnace atmosphere are all critical considerations.
