Assessment of Active Filters for High Quality Aluminium Cast Products

Abstract

The quality requirements of aluminium products are constantly increasing. It is critical that ingots and billets have the least amount of inclusions in the as-cast product. Filtration is therefore applied to all critical products, ceramic foam filtration (CFF) being the most frequently used technique. In an attempt to increase inclusion capture by CFF the influence of the filter surface chemistry on the filtration efficiency of aluminium alloys has been evaluated. Lab scale filters have been produced with coatings of different chemical composition. The filters have been characterized prior to usage and lab scale casts have been made on a pilot unit in conjunction with two LiMCA for inclusion removal efficiency determination. The paper will present the results from the characterization done and the observations will be discussed.