Ceramic fiber wool porous insulation can form a stable structure with very little material (fibers). Compared with ceramic porous insulation materials, ceramic fiber cotton insulation materials have the characteristics of lightweight, porous, low thermal conductivity, and strong specific heat capacity, and can withstand strong loads. The raw material has been used in several fields such as filtration extraction, temperature insulation, life science research, and synthetic materials. The recyclable heat protection frame embodied by the heat insulation coating made of ceramic fiber cotton raw materials is widely used in the heat protection system of various professional airliners all over the world, and has both important practical value and industry prospects.
Ceramic fiber cotton can be divided into two categories: non-oxidizing material nylon fiber (such as SiC cellulose, C cellulose) and oxidizing material (including composite oxidizing material) nylon fiber (such as aluminum silicate fiber blanket, Al2O3 cellulose).
(1) Ceramic fiber cotton: silicon carbide fiber. Silicon carbide (SiC) is generally called diamond and silicon carbon, and is a synthetic compound formed by covalent bonds. It can be prepared by chemical industry gas chromatography accumulation method, carbothermal reduction method, powder roasting method, and advocate body conversion method. Pure silicon nitride has no color and transparency. Silicon nitride used in manufacturing often contains tempered glass, iron, silicon, carbon and other impurities, which are light green or black.
Ceramic fiber cotton: silicon nitride has good oxidation resistance, high temperature compressive strength and stability, thermal conductivity, bulk density, low linear expansion coefficient, thermal deformation and other high temperature properties, so it can be used in high temperature weather Combustion chamber of gas turbine, high temperature nozzle, stator blade of turbine, etc. Silicon carbide has the characteristics of high thermal conductivity and insulation performance, and can be used as high-temperature heat exchangers for metallurgical industrial furnaces, substrates for large-scale integrated circuits, and packaging materials.
Ceramic fiber cotton: In addition to good physical properties, silicon carbide also has excellent chemical properties. In a non-oxygen atmosphere, the surface of silicon carbide contains only 5% silicon at 2300, but when silicon carbide is exposed to oxygen, the surface begins to oxidize, but silicon carbide can produce a SiO2 protective film to prevent the oxidation reaction from continuing.
(2) Ceramic fiber cotton: carbon fiber. Carbon fiber is a fiber-type carbon material, organic fiber is heated to more than 1000 in an inert gas, and contains more than 90% fiber-type carbon. Carbon fiber is a new type of inorganic substance with a density of 1.5-2g/cm3. It is 1/4 of the density of steel and 1/2 of the density of aluminum alloy. But its strength is 4.5 times greater than that of steel. The thermal expansion coefficient is small, the thermal shock resistance is good, even if the high temperature suddenly drops from several thousand degrees Celsius to normal temperature, it will not explode, and the lubricity and conductivity are very good. The chemical properties of carbon fiber are similar to carbon, generally alkaline and inert, and not brittle at the temperature of liquid nitrogen.