Ceramic Foam Filters (CFF) for metal filtration have been used commercially in the foundry industry for more than forty years, are used to produce high-quality aluminum castings for applications such as the aerospace industry.
In recent years, for the non-ferrous metal industry, ceramic foam filters for metal filtration have become more and more important in the physical purification of metals. The non-ferrous industry uses this kind of filter media in the largest amount, especially the aluminum casting industry. In 1992, it was reported that 8 million tons of aluminum were filtered using CFF, which meant that about 50% of all aluminum produced in the world that year was purified by this filter medium. High-temperature alloys also use CFFs, such as superalloys, carbon steels, and alloy steels that use CFFs.
Porous ceramics are now widely used as a material for fluid filtration in high-temperature applications. It is generally believed that based on their structural characteristics, CFFs can remove exogenous and endogenous inclusions in the melt, and have low flow resistance and high filtration efficiency for particles larger than 10-20 microns.
The structure of CFF creates a unique tortuous path for fluid flow, which traps inclusions and allows clean, smooth metal to enter the cavity. CFF is generally considered to be the best filter for casting. Their main advantages are: high filtration efficiency, reduced turbulence, fire and erosion resistance, and are suitable for the most demanding casting applications.
Filtration is an important part of every manufacturing and casting industry. Different industries make use of different materials for filtering their finished products. Alumina ceramic foam filter is used in foundries casting molten aluminum. Aluminum is known to be the best material which has a lot of applications and the foundries help in molding the molten aluminum into different structures for better usage of the metal. But unless it is filtered with well-efficient tools, the process remains incomplete. The presence of impurities and other unwanted products in the metal decreases the quality of the metal thereby decreasing the quality of the materials cast from the metal. The ultimate aim of the foundry is to make a profit and good quality of the casted material can help in achieving it.