Lightweight refractory material - ceramic fiber
Apr 07, 2022
Ceramic fiber is a fibrous material made from natural or artificial inorganic materials by different processes, or converted from organic fibers by high temperature heat treatment. In addition to excellent mechanical properties, it also has the advantages of anti-oxidation and good thermal stability.
1. Types of ceramic fibers
The varieties of ceramic fibers mainly include ordinary aluminum silicate fibers, high-alumina aluminum silicate fibers, polycrystalline alumina fibers, polycrystalline mullite fibers and high-performance ceramic fibers. Among them, silicon carbide fiber is one of the high-performance ceramic fibers. Silicon carbide fiber is an important high-performance reinforced ceramic fiber for metal matrix and ceramic matrix composites. It has excellent tensile strength, creep resistance, oxidation resistance, and compatibility with ceramic matrix.
2. Preparation method of ceramic fiber
A. Physical molding method
Melt fiberization method: After the raw material is melted, the fiber is formed by the blowing method or the spinning method.
Blowing method: First, the raw material is melted into a high-temperature melt with a resistance furnace, and a thin stream is formed through a high-temperature orifice, which is sprayed with high-pressure air. Under the action of high-speed air, the molten liquid is dispersed into particles, and fibers are formed between the particles.
Spinning method: The high-temperature molten liquid is formed into fibers by the centrifugal force of the high-speed rotation of the spinning wheel.
B. Matrix fiber solution impregnation method
Most of the matrix fibers are viscose fibers with good hydrophilicity. The matrix fiber solution impregnation method is to impregnate the matrix fiber with an inorganic salt solution, and then sinter to remove the matrix fiber to obtain the ceramic fiber. The fiber strength mainly depends on the porosity of the fiber and the size of the metal oxide grains. This method is simple and easy to popularize.
In addition, it can also be prepared by chemical vapor deposition, chemical vapor reaction, and precursor conversion methods.
3. Application of ceramic fiber
A. Used in industrial furnaces
As a lightweight and efficient thermal insulation material, ceramic fiber is widely used in industrial furnaces. It can greatly reduce the load on the steel structure of the furnace and prolong the service life of the furnace body.
B. Can be used as filter material
Ceramic fibers are thin in shape and can be used as filter materials. The use of ceramic fiber filters in factories to directly filter high-temperature flue gas can reduce the equipment requirements and costs for cooling the gas before filtering, and can reduce heat loss and resource waste caused by cooling.
C. Making ceramic fiber composites
Ceramic fiber composites are exceptional materials that not only resist rapid and intense temperature changes without damage, but also replace metallic superalloys and outperform such alloys in terms of temperature resistance, specific strength and specific modulus .
