Alumina ceramic foam filter is a kind of porous material, which has a three-dimensional network structure and high porosity characteristics. Its function is to make the turbulent and churning molten metal become stable, uniform, and clean after passing through the foam ceramic honeycomb holes, thereby greatly reducing the casting waste rate caused by casting defects such as non-metallic inclusions and saving production costs.
Problems that should be paid attention to in the use of alumina ceramic foam filter:
1. In order to ensure the full filtration of the molten metal, the filter must have a certain pressure head for starting filtration to overcome the obstacle of surface tension. The pressure head size has a considerable effect on the start of the filter. Generally, it should be greater than 400mm. For large castings, the indenter should be correspondingly larger.
2. The overlapping part of the alumina ceramic foam filter and the mold should be sealed as far as possible to prevent the metal liquid from being lost from the gap, causing the filtering effect can not achieve. For some sand molds, such as green sand, the use of ceramic foam filters alone can easily cause the sand to fall off where the filter is placed. Therefore, a filter seat must be designed to support the filter so that the filter does not move under the impact of molten metal, so as to prevent sand particles from entering the cavity and metal liquid loss.
3. Before using the foam ceramic filter, compressed air should be used to blow off the surface dust and internal fragments to prevent impurities from contaminating the molten metal. Avoid moisture during transportation and storage, it should be stored in a dry environment. If necessary, bake before use to make the filter fully dry. In addition, the filter is a fragile product, so it should be handled with care to prevent damage.