Ceramic foam filter is a new type of industrial ceramic product with low bulk density (0.25~0.65) g/cm3, high porosity (60%~90%), and three-dimensional network structure. Because ceramic foam filter has excellent properties, such as high-temperature resistance, strong chemical resistance, and large surface area due to high porosity, it is widely used in molten metal filtration to remove undesirable non-metallic inclusions in the melt.
In fact, molten metal, especially molten aluminum, often contains entrained solids, which are harmful to the final cast metal product. These entrained solids appear as inclusions in the final cast product after the molten metal is solidified, and cause the ductility of the final product to decrease or the smoothness and anodizing properties of the final product are poor. Inclusions may come from several sources. For example, inclusions may come from a surface oxide film that is broken and entrained in the resulting molten metal. In addition, inclusions may come from insoluble impurities, such as carbides, borides, etc., or corroded furnace and trough refractories.
The advantages of ceramic foam molten metal filter include:
Reduce the gas and inclusions contained in the casting, reduce the turbulence of the molten metal when filling the mold, reduce the surface defects in the casting, and significantly reduce the rejection rate of the casting.
Increase the compression and sealing of the casting, increase the elongation and tensile strength of the casting, improve the surface finish of the casting, increase the fluidity of the molten metal, and increase the filling capacity and feeding capacity of the melt.
Simplify the casting system, reduce the length of the lateral flow channel, and increase the casting output.
Reduce processing time and tool wear and improve the surface quality of castings.
Ceramic foam has high mechanical strength, chemical stability, high thermal shock resistance, and liquid metal flow shock resistance even in high-temperature environments. There is no slag or broken during processing to ensure the quality of molten metal and stable chemical composition.
With large and stable metal flow, even if the molten metal contains high inclusions, it will not block the ceramic foam filter. It has high dimensional accuracy and can be automatically placed on the production line.