抄録
Large amounts of Al-Si-X casting alloy are used for automotive parts in order to reduce the weight of automobiles. These kinds of alloys are favorable for recycling. However, during the process of recycling, the chemical composition of impurity elements, such as Fe, Mn, and Cr, often increases. These elements tend to form large size intermetallic compounds during solidification, degrading the mechanical properties of castings. For this reason, numerous researches on this problem have been reported in recent decades.
This review is written as a summary of some of the representative reports on the problem of Fe-based intermetallic compounds in Al-Si-X casting alloys. This review also provides information on the addition of manganese and chromium which causes intermetallic compounds to transform into different shapes, and reduces adverse effects on mechanical properties.
When deciding the allowable composition of iron in the Al-Si-X alloy, the kind of phases, size and shape of iron intermetallic compounds are important. There are many reports on the influence of β iron intermetallic compounds on the mechanical properties of Al-Si-X alloy, as well as many reports on the influence of manganese and chromium on the shape of iron intermetallic compounds, but hardly any on how much the α iron intermetallic compounds affect the mechanical properties of Al-Si-X alloys.
