Research On The Elimination Of Iron Phase Impurity In Molten Al-Si Alloy

Aluminum has excellent physical and chemical properties and is widely used in building materials,product packaging,automotive,military and aerospace industries.However,in the process of recycling of used aluminum products,various brands of aluminum alloys are mixed with each other,resulting in the inclusion of other impurity elements during the remelting process,in which iron impurities continue to accumulate in use,seriously affecting the performance of aluminum alloys.Therefore,the development of a practical and efficient iron removal technology is of great significance to the healthy development of China's aluminum industry.At present,the iron phase impurities in aluminum alloys mainly change the iron phase morphology by metamorphic technology or reduce the iron content by precipitation technology,but the effect of the combination of the two on Fe phase is less.Therefore,it is necessary to combine the metamorphic technology to comprehensively explore the influence of the change of the morphology of the iron phase on the sedimentation effect.If feasible,it is a new research direction of iron removal.Firstly,the paper mainly discusses the effect of adding Mn,Sr modifier and compounding Mn and Sr modifier on the morphology of iron phase in the alloy.It is found that 0.05wt%Sr and Mn/Fe are added after the addition of Mn and Sr modifier.When the ratio is 1.0,the acicular iron phase is converted into a bar shape,and the resulting bar-shaped?-Fe phase is smaller than when Sr is not added.The Al₁₃Fe₄ phase disappeared in the alloy,and a large amount of A₁₅Mn₁₂Si₇ phase was formed.It can be seen that the addition of Mn and Sr elements can reduce the formation of AlFe phase in the alloy and convert the acicular iron phase into?-Fe phase.Secondly,combined with the relatively optimal addition ratio of Mn and Sr modifiers,KBF₄ was added to study the effect of KBF₄ on the iron removal effect of aluminum alloy after iron phase modification.It has been found that the iron removal phase is higher at the bottom of the sample after adding the modifier,which is beneficial to increase the iron removal efficiency.After adding the NaCl+KCl flux,the melting temperature of the KBF₄ can be lowered and the melting can be reduced.Body viscosity,increasing the sedimentation rate of the iron phase.It is found that after adding 1.5wt.%KBF₄,The iron content is 0.68wt.%.After adding the modifier and iron removal agent,The iron content is 0.66wt.%,which indicates that the iron phase has undergone metamorphism and has the effect of removing iron.enhancement.XRD analysis showed that AlB₂ appeared in the sample except Fe₂B.The results showed that the added KBF₄ did not completely react with the iron phase,and some of it would reaction occur 3Al?l?+2KBF₄?s?=AlB₂?s?+2AlF₃?s?+2KF?s?.Finally,by adding K₂TiF₆,Mn and other substances to the aluminum melt,the effects of K₂TiF₆ and Mn on the iron phase change were studied.It was found that the iron removal was compared with the addition of Mn,and the composite was added with Mn and K₂TiF₆.The amount of massive iron precipitated at the bottom is more than that of K₂TiF₆ alone,indicating that the addition of Mn to the K₂TiF₆ can promote the change of the morphology of the iron phase and Transforming the acicular iron phase morphology into a round iron phase.It is found that after adding 2.0wt.%K₂TiF₆,The iron content is 0.84wt.%.After adding 1wt.%Mn and 2.0wt.%K₂TiF₆,The iron content is 0.59wt.%,which indicates that the iron phase has undergone metamorphism and the iron removal effect.There is a promotion.XRD analysis revealed that the TiFe₂ phase did not appear in the sample.The results show that the added K₂TiF₆ does not react with the iron phase.The addition of K₂TiF₆ promotes the morphology polymerization process of the acicular Fe phase,making the Fe phase easier to settle to the bottom of the crucible under the action of gravity.