The influence of alumina on ceramic fiber blanket is mainly reflected in the following aspects:
1. The influence of physical properties
1. Stretch index:
When alumina is added during the production of ceramic fiber blankets, the tensile index of ceramic fiber blankets changes as the amount of alumina usage increases. For example, when the amount of colloidal alumina is increased from 20% to 25%, the tensile index increases from 0.82 Nm/g to 0.91 Nm/g, an increase of 11.0%. When the amount of alumina is increased from 25% to 40%, the tensile index increases more significantly, and the final increase reaches a high level. However, with the further increase in the amount of alumina, the growth trend of the tensile index may gradually slow down or even decrease. These results indicate that the addition of alumina can effectively improve the tensile properties of ceramic fiber blankets, but excessive addition may have adverse effects.
2. Loss on ignition:
The addition of alumina will also lead to an increase in the loss on ignition of ceramic fiber blankets. Loss on ignition refers to the percentage of mass reduction of a sample after burning under certain conditions. As the amount of alumina increases, so does the loss on ignition. For example, in the range of alumina dosage from 20% to 40%, the amount of ignition increases sequentially, but the increase gradually decreases. This indicates that the addition of alumina has a certain effect on the thermal stability of the ceramic fiber blanket, which needs to be controlled during the production process.
Second, the influence of chemical properties
1. Fire resistance and corrosion resistance:
Alumina is a compound with high hardness and is extremely resistant to fire and corrosion. Therefore, when the content of alumina in the ceramic fiber blanket increases, its fire resistance and corrosion resistance will also increase accordingly. This makes the ceramic fiber blanket able to maintain stable chemical properties in a high-temperature environment, and is not easy to fail due to oxidation, reduction and other reactions.
2. Thermal insulation performance:
The addition of alumina also helps to improve the thermal insulation properties of the ceramic fiber blanket. Alumina has good thermal stability and can effectively prevent the transfer of heat. Therefore, ceramic fiber blankets with high alumina content have a lower thermal conductivity and can better play the role of thermal insulation.
Third, the influence of the production process
The amount and form of alumina also have a certain impact on the production process of ceramic fiber blanket. In the production process, it is necessary to select the appropriate amount and form of alumina according to the performance requirements and production conditions of the ceramic fiber blanket. For example, too much alumina addition may lead to problems such as poor fluidity and difficult molding in the production process; Different alumina forms (e.g., α-Al2O3, β-Al2O3, γ-Al2O3) may have different effects on the final performance of the product.
To sum up, the impact of alumina on ceramic fiber blanket is multifaceted, including physical properties, chemical properties and production process. In the production process, it is necessary to select the appropriate amount and form of alumina according to specific needs to obtain ceramic fiber blanket products with excellent performance.