Continuous Removal of Nonmetallic Inclusions from Aluminum Melts by Means of Stationary Electromagnetic Field and DC Current

Abstract

In order to continuously remove small nonmetallic inclusions from aluminum melts, stationary electromagnetic field and direct current (DC) were simultaneously applied to the aluminum melt. The principle of removal of nonmetallic inclusions from aluminum melts is that electromagnetic force (EMF) scarcely acts on the nonmetallic inclusions due to its low electric conductivity as compared to the aluminum melt. As a result, a repulsive force exerts on the nonmetallic inclusions to move them in the direction opposite to that of the EMF. Al2O3 particles (>15 μm) were chosen to simulate nonmetallic inclusions in aluminum melt. Experimental results show that all Al2O3 particles larger than 15 μm were removed after treatment with the electromagnetic separation chamber. It was found that the tensile strength of the Al-Cu alloy processed by degassing and electromagnetic separation was 7.72 pct higher than that processed by degassing only and 2.70 pct higher than that processed by degassing with subsequent filtration.