Effect of Iron and Magnesium on Alloy AL9M Structure and Properties

Resumo

The effect of iron impurity on the structure and properties of aluminum alloy AL9M, especially its action on magnesium distribution within the structure, is studied. The microstructure of a cast component of this alloy broken during operation is analyzed. It is shown that iron impurity has an unfavorable effect on structure and mechanical properties of a casting due to appearance of Al₉Fe₂Si and Al₁₈Fe₂Mg₇Si₁₀ intermetallics. Formation of these intermetallics consumes a considerable amount of magnesium and lowers the content of the Q(Al₅Cu₂Mg₈Si₆) strengthening phase in the alloy structure.