REMOVAL OF IRON AND MANGANESE IN ALUMINIUM ALLOYS BY ADDING MAGNESIUM AND SUBSEQUENTLY CENTRIFUGING

摘要

The content of Fe and Mn is critical for the final properties of several alloys. The feasibility of the removal of Fe and Mn by primary crystals precipitation has been studied. Different amount of magnesium was added to Al-1%Mn-1%Fe-1%Si melts. The content was varied from 0 to 17 wt% Mg. Then the melts were homogenized and slowly cooled to a temperature about 10°C above the liquidus temperature of Al-crystals and held for four hours. A series of intermetallic particles was formed during this treatment. These particles were separated from the melt by the subsequent centrifuging of the molten metal. Microprobe analysis of the particles showed large particles of α-Al(Mn,Fe)Si, Al6(Mn,Fe), Φ-(Al,Si)10(Fe,Mn)_3 and Al_3(Fe,Mn) of size 0.04-0.4 mm. The contents of Mn and Fe in the purified metal were correspondingly reduced to 0.10 wt%Mn and 0.13 wt%Fe (X-ray fluorescence measurements) in metal containing more than 12 wt%Mg.