Theoretical and experimental investigation of aluminum melt cleaning using alternating electromagnetic field

Effects of processing variables using such as the frequency of imposed field (f), imposed magnetic flux density (Be), processing time (t), the diameter of inclusions (dp) and the ratio of pipe radius to skin depth (r1/δ) on the electromagnetic separation (EMS) removal efficiency of inclusions from an aluminum melt were analyzed theoretically. It was found that the removal efficiency (η) reaches a maximum while r1/δ ranges from 1.5 to 2. In addition, wider effective range of r1/δ will be obtained with larger dp or higher f. Experimental results on aluminum melt show that higher frequency and magnetic flux density make for higher removal efficiency, matching well with the theoretical results. In the case of f=15.6 kHz, Be=0.1 T and t=10 s, more than 80% inclusion particles with 6-μm diameter can be removed. [Copyright &y& Elsevier]