Fe is the most detrimental impurity element in recycled Al-Si alloys due to the formation of brittle,primary,Fe-containing,intermetallic particles during solidification.Their removal from the Al-Si melts e.g.by filtra...Fe is the most detrimental impurity element in recycled Al-Si alloys due to the formation of brittle,primary,Fe-containing,intermetallic particles during solidification.Their removal from the Al-Si melts e.g.by filtration can reduce the Fe content.New active filter materials can facilitate the formation of these particles for their removal and contribute to the production of high-quality,recycled Al-Si alloys.The interaction of the alloy with the filter material can lead to modification of the thermodynamics of the alloy or of the kinetics of the particle formation.Time-resolved,three-dimensional microstructural inves-tigations have been carried out to study the formation of primary intermetallic particles in Al7.1Si1.5Fe and Al7.1Si0.75Fe0.75Mn alloy melts in contact with Al_(2)O_(3)and Al_(2)O_(3)-C filter substrate material during a melt conditioning treatment at 620℃.The microstructures,in particular the primary intermetallic particlesαc andαh,have been characterized by computed tomography(CT)and supplementary scanning electron microscopy(SEM).As expected by thermodynamics,the total volume fraction of primary par-ticles remains unchanged by the interaction with the substrate materials.However,kinetic advantages for Fe-removal efficiency can be achieved by an accelerated and preferred selective particle formation in contact with the Al_(2)O_(3)-C material.Furthermore,particle formation is discussed in view of its different stages:nucleation,growth,and ripening.展开更多
基金the German Research Foundation(DFG)for supporting these investigations as part of the Collaborative Research Centre 920“Multi-Functional Filters for Metal Melt Filtration-A Contribution towards Zero Defect Materials”(Project-ID 169148856)in sub-project A07 and C06Support from the Danish National Facility for Imaging with X-rays,DANFIX,funded by the Danish Agency for Science and Higher Education,grant ID 5072-00030B is acknowledged.
文摘Fe is the most detrimental impurity element in recycled Al-Si alloys due to the formation of brittle,primary,Fe-containing,intermetallic particles during solidification.Their removal from the Al-Si melts e.g.by filtration can reduce the Fe content.New active filter materials can facilitate the formation of these particles for their removal and contribute to the production of high-quality,recycled Al-Si alloys.The interaction of the alloy with the filter material can lead to modification of the thermodynamics of the alloy or of the kinetics of the particle formation.Time-resolved,three-dimensional microstructural inves-tigations have been carried out to study the formation of primary intermetallic particles in Al7.1Si1.5Fe and Al7.1Si0.75Fe0.75Mn alloy melts in contact with Al_(2)O_(3)and Al_(2)O_(3)-C filter substrate material during a melt conditioning treatment at 620℃.The microstructures,in particular the primary intermetallic particlesαc andαh,have been characterized by computed tomography(CT)and supplementary scanning electron microscopy(SEM).As expected by thermodynamics,the total volume fraction of primary par-ticles remains unchanged by the interaction with the substrate materials.However,kinetic advantages for Fe-removal efficiency can be achieved by an accelerated and preferred selective particle formation in contact with the Al_(2)O_(3)-C material.Furthermore,particle formation is discussed in view of its different stages:nucleation,growth,and ripening.
