Why is white fused alumina widely used in spraying?
There are many types of abrasives available for spraying, such as brown fused alumina, white fused alumina, black silicon carbide and green silicon carbide.
Furthermore, white fused alumina and brown fused alumina share many similar characteristics, but most manufacturers still prefer white fused alumina.
Why is white fused alumina widely used in spraying?
White Fused alumina is made from high-purity alumina, melted and crystallized in an electric arc furnace at temperatures above 2000℃. Its dense crystal structure and high hardness result in less dust and less harm to operators and environmental pollution during spraying compared to brown fused alumina or silica sand.
The core advantages of white fused alumina as a high-temperature refractory spraying abrasive include:
- Extremely strong refractoriness and thermal stability. White fused alumina has a melting point as high as 2050℃ and a refractoriness of 1900℃. Therefore, it maintains structural stability and is not easily softened or deformed even in high-temperature environments above 1600℃ (such as electric furnaces for steel smelting and glass melting furnaces). Low coefficient of thermal expansion and strong thermal shock resistance, effectively resisting thermal stress caused by sudden temperature changes and reducing the risk of cracking.
- High aluminum oxidecontent and few impurities
Because white fused alumina is produced by high-temperature melting, it contains almost no iron or other metallic impurities. This characteristic makes it less prone to reacting with furnace materials and flue gas at high temperatures, resulting in strong corrosion resistance, making it particularly suitable for industrial environments with high cleanliness requirements.
- Good chemical stability
White fused alumina is resistant to strong acids and alkalis, ensuring stable chemical properties even in high-temperature environments. It will not chemically react with the coating substrate or working medium, ensuring long-term coating reliability.
- High hardness and mechanical strength
White fused alumina has high hardness, with a Mohs hardness of 9.0, exhibiting extremely strong erosion and wear resistance. As an aggregate in spray coatings, it can significantly improve the hardness and service life of the coating, performing exceptionally well in heavily abrasive environments such as mining machinery and cement kilns.
- Low thermal conductivity, providing some insulation
As a spray coating material, white fused alumina’s low thermal conductivity helps reduce heat loss, and its high-temperature oxidation resistance ensures the long-term stability of the product.
In summary, white fused alumina was chosen as a spray coating material due to its inherent characteristics.