Jul 06 , 2025
Both High-Density Calcium Silicate Boards and Fused Silica are popular choices for constructing launders in aluminum casting operations, but they offer distinct advantages and disadvantages that influence their suitability for different applications.
High-density calcium silicate boards, often reinforced with fibers like carbon fiber, are specifically engineered for molten aluminum contact.
Exceptional Non-Wetting Properties: This is their standout feature. Molten aluminum resists adhering to the board's surface, significantly reducing dross formation and metal loss, and simplifying cleaning.
Superior Insulation Performance: Calcium silicate is an excellent insulator. Its low thermal conductivity helps maintain stable aluminum temperatures along the launder, minimizing heat loss and promoting energy efficiency.
Good Thermal Shock Stability: These boards can withstand rapid temperature changes, crucial during molten metal pouring and draining, without cracking or spalling.
Easy Machinability: They can be precisely machined into complex shapes using CNC equipment, allowing for custom launder designs and intricate flow control components.
Lighter Weight: Compared to fused silica, they are generally lighter, making handling and installation easier.
Primary Application: Ideal for launders, transition plates, and hot top casting components where energy saving, non-wetting performance, and ease of fabrication are paramount.
Fused silica is a high-purity ceramic material made from melting and solidifying quartz.
Outstanding Thermal Shock Stability & Extremely Low Thermal Expansion: This is its most significant advantage. Fused silica can endure severe temperature fluctuations without cracking, making it incredibly reliable in demanding thermal environments.
Excellent Corrosion Resistance: It exhibits high chemical stability against molten aluminum and common fluxes, resisting chemical attack and erosion.
High Purity: Its high purity minimizes the risk of contaminating the molten aluminum.
Good Mechanical Strength: It offers robust mechanical strength, capable of withstanding the flow and impact of molten metal.
Higher Density: Generally denser and heavier than calcium silicate boards.
Primary Application: Widely used for launders, pouring nozzles, and other critical parts in continuous casting and other high-demand processes where extreme thermal shock resistance, high strength, and purity are essential.
Feature | High-Density Calcium Silicate Boards | Fused Silica |
Primary Advantage | Excellent Non-Wetting, Superior Insulation, Easy Machinability | Extreme Thermal Shock Stability, Low Thermal Expansion, High Purity |
Main Function | Insulation, anti-drossing, precise flow guidance | High-temperature resistance, anti-thermal shock, high-purity flow |
Density/Weight | Relatively lower/lighter | Relatively higher/heavier |
Brittleness | Less brittle, more forgiving during handling | More brittle, requires careful handling |
Cost | Generally more economical | Typically higher |
Ideal Application | Energy saving, anti-sticking, intricate shapes, general flow systems | Extreme thermal stability, high strength, high purity, critical casting components |
Choosing between these materials depends on specific application requirements. If energy efficiency, dross control, and ease of fabrication are top priorities, high-density calcium silicate boards are often preferred. For applications demanding ultimate thermal shock resistance, mechanical strength, and purity, fused silica is typically the superior choice.
