Deep filtration of molten aluminum using ceramic foam filters and ceramic particles with active coatings

Abstract

The inclusions in molten aluminum were removed using the deep filtration of ceramic foam filters and ceramic particles with active coatings. The results of tensile tests showed that the elongation of the filtered tensile specimen S 6 increases by 17.93 pct, but the tensile strength does not. The scanning electron microscope (SEM) examination showed that the secondary cracks and dimples in the filtered tensile specimen S 6 were finer and more homogeneous than those in the unfiltered tensile specimen S 0 . In addition, metallographic examination showed that there were only a few inclusions of approximately 6 mm in diameter in the filtered specimen S 6 , but more inclusions of approximately 40 mm in diameter were found in the unfiltered specimen S 0 . The filtration efficiency of the coated ceramic particles was higher than that of the coated ceramic foam filters. The active coating could effectively capture the inclusions and dissolve Al 2 O 3 in them during filtration.

Wetting and its influence on the filtration ability of ceramic foam filters

“…Deep bed filtration is a widely accepted theory for describing metal melts filtration (Conti & Netter, 1992;Damoah & Zhang, 2010;Raiber, Hammerschmid, & Janke, 1995;Zhou et al, 2003). The filtration process can be classified into two steps: the probability of contact and the probability of adhesion.…”

Simulation of Fluid and Inclusions Dynamics during Filtration Operations of Ductile Iron Melts Using Foam Filters

“…[1,2] The physicochemical aspects of filtration, including the surface tension properties of the phases involved and the filter structure, were addressed by various researchers. [3][4][5] The application of ceramic filters to the continuous casting of steel was also proposed, [6,7] but the length of the casting cycles rendered filters useless, either because of clogging or excessive wear or both.…”

“…[3], to calculate the velocity vector of an inclusion; the result is used in Eq. [4], to calculate its vector position. The final version of Eq.…”

Interaction of AlSi7Mg with Oxide Ceramics

“…[1][2][3][4][5][6][7][8] During the last years, new filtering techniques and new active filter materials have been developed to expand the range of application and to improve filter efficiency. [9][10][11][12][13][14][15] Hereby, several authors supposed an influence of the wetting behavior on the filtration efficiency. [15][16][17][18] But there are fundamental differences in determining the wettability of aluminum and its alloys by the classic sessile drop technique comparing to the wettability during real filtration terms.…”