전자기장을 이용한 난연속주조성 알루미늄 합금 빌렛 주형 내 유동 특성에 관한 연구

Abstract

This study introduces how to improve ingot quality of high-solute aluminum alloy using EMS(ElectroMagnetic Stirrer) during semi-continuous direct chill casting. Because the demand of the high performance and low weight characteristics of aluminum alloy in the transportation industry goes high, the aluminum ingot makers tend to increase the content of the solute element in aluminum alloy in order to make the better material properties. However, high-solute aluminum alloy has the problem that the defects easily occur during casting process such as porosity, micro segregation and crack compared to low-solute aluminum alloy’s case. It’s because high-solute aluminum alloy has the wide mushy zone which causes poor liquid flow in it and low activated liquid flow is the main factor of variable defects in aluminum alloy. Therefore, in order to reduce defects in high-solute aluminum alloy, it’s very important to control the liquid flow in the mushy zone. EMS is the appropriate method to activate liquid flow because EMS generates Lorentz force which can develop flow pattern in the mushy zone of molten aluminum. The purpose of this study is to find optimal current and frequency condition of EMS in the laboratory equipment of direct chill casting by means of numerical method.