Zirconia fiber is a kind of polycrystalline inorganic refractory fiber. According to the molding process, there are: solution dipping method, solution spinning pyrolysis method, solution electrostatic spinning method, colloidal drawing method, colloidal spinning method, slurry extrusion method, etc. It is resistant to high temperatures (long-term use temperature>=1000°C; instantaneous use temperature>=1600°C), oxidation resistance, acid and alkali corrosion resistance, stable chemical properties, excellent heat insulation performance, and insulation at room temperature but conductive at high temperatures, so zirconia Fiber and its products Fiberboard, fiber cloth, fiber felt, etc. have great application requirements in aerospace, atomic energy, metallurgy and petrochemical industries.
1. Solution spinning pyrolysis method: This method uses a zirconium salt solution with a certain viscosity and small surface tension as the filament forming material. The solution is sprayed into the hot air through a nozzle. The sprayed solution has a certain viscosity and is hot When moving in the air, the filaments can be maintained, and the solvent in the filamentous solution evaporates to obtain zirconia fibers.
2. Colloidal spinning method: Put the viscous liquid in a high-speed centrifuge. Under the action of high-speed centrifugal force, the fluid passes through special pores. Because the fluid itself has a certain viscosity, thin fibrous filaments are formed. German company patent It is a mixed solution of organic polymer with a certain viscosity and water-soluble zirconium salt, which is centrifuged into zirconia fiber by high-speed centrifuge.
3. Slurry extrusion method: The slurry extrusion method prepares zirconia ceramic fiber by uniformly mixing organic binder and zirconia particles with a particle size in the range of 50nm-1um, extruding into mud sticks, and then firing at high temperature. Obtain zirconia ceramic fiber.
4. Solution dipping method: This method is convenient to make and the raw materials are easily available. The felt and paper can be directly prepared without additional weaving process. In addition, the production area is small. But the viscose filament is immersed in the solution to obtain the precursor. The probability that the particles fill the pores of the viscose filament is random. The content of the precursor is low, the organic content is high, and the volume shrinks during the sintering process. The process is controlled. Complex, sometimes the obtained fiber particles are not uniform enough, and the porosity is high.