Refinement and migrating behaviors in Al-Si hypereutectic alloys solidified under electromagnetic vibration

Jianbo YU , Zhongming REN and Kang DENG Shanghai Enhanced Laboratory of Ferro-Metallurgy, Shanghai University, Shanghai 200072, China

摘 要：The effects of electromagnetic vibration （EMV） on the refinement and migration of primary silicons in the Al-18 wt pct Si alloy were investigated systematically. It was found that EMV could effectively refine primary silicons. The equivalent diameter of primary silicon first decreases slowly with the current increasing from 1 A to 3 A, but then drops rapidly between 3 A and 10 A, next gradually decreases with increasing current intensity. When the EMV intensity was low, the primary silicons were agglomerated and expelled to the top of a sample, the segregation of silicon grains gradually decreased and the agglomerating phenomena disappeared with the increase of EMV intensity, and the star-like coarse primary silicons turned refined flake or square morphology. The refinement and migration of primary silicons depended on the Lorentz force, gravity and the effective viscous force.

关键词：