한국주조공학회

The growing use ofaluminum for castings over the past decade has brought with it the increased scrutiny ofcomponent properties One area that has received much attention is the effect of in inclusions - or impurities particles held in the metal - on castig properties. A new method of electromagnetic separation for removal of inclusions in aluminum alloy melts is proposed. The principle is that as the electromagnetic force induced in metal acts on inclusions due to low electric conductivity, they are moved to the direction opposite to electromagnetic force and can be separated and removed from the melt. Experiments were carried out on A356 melt mixed alumina particles and commercial Al alloys ofADC 10 and 12. In the experiment using A356, it was proved that A1203 particles was separated and removed continuously from matrix melt by electromagnetic force. Based on these results, the continuous separation experiment that used ADC 10, 12 was carried and the cleanliness ofmelt was assessed by the amount of porosity, hydrogen contents, PODFA and mechanical properties through tensile test. As the results of analyses, the amount of porosity and hydrogen contents decreased without variation of chemical composition in the specimen that passed the electro- magnetic continuous separator. In addition, tensile strength and elongation of this specimen increased by 20~30% because of reduction of inclusions.

Electromagnetic (Archimedes) force, Inclusions, Cleanliness, PoDFA, Mechanical properties