Interaction of iron-nickel alloys with liquid aluminium - Part II - Formation of intermetallics

The phase composition of the one-phase intermetallic layer(s) and two-phase reaction zone(s) at the interface between a solid iron-nickel alloy, conta ining 90, 75, 50, 25, 20, 15 and 10 mass% Fe, and the aluminium melt, satur ated with alloy constituents at 700 degrees C, was studied by electron prob e microanalysis. The formation of binary (FeAl3, Fe2Al7, NiAl3 and surprisi ngly NiAl2 rather than Ni2Al3) and ternary (FeNiAl9) intermetallic compound s was observed. All the binaries were found to dissolve considerable amount s of a third element (Ni or Fe) and to have a noticeable range of homogenei ty. Dissolution of the Fe-Ni alloy base into pure liquid aluminium resulted in a large decrease (three to five times) of the layer thickness compared to the case of the saturated melt. (C) 2000 Kluwer Academic Publishers.