Abstract
The constitution of Copper rich Cu-Al-Fe alloys containing up to 20 per cent. of aluminium and up to about 10 per cent. of iron was determined. A ternary phase, which is formed by a peritectic reaction, Liquid+Feγ_??_T, was found to exist, to which phase the authors named “T”.
The true natur of this ternary phase has not been thoroughly examined but its existence is ascertained by microscopical examination. The T phase has a large solubility of iron and aluminium, the homogeneous field extending from 20 to 27 per cent. of aluminium and from 25 to 45 per cent. of iron at room temperature.
The following invariant reactions were found to exist on solidification and in the solid state.
Liquid+T_??_β+Feγ 1048°
Liquid+Feγ_??_α+β 1046°
Liquid+β_??_γ1+T 1015°
β+Feα_??_α+T 750°
α+Feγ_??_β+Fexχ about 950°
β_??_α+γ2+T 560°
The latter ternary eutectoid reaction occurs at a temperature approximately 20° below that of the eutectoid temperature of copper-aluminium binary alloys.
The γ2 phase of the Cu-Al system forms a range of solid solution, the maximum solubility of which with iron is about 2 per cent. at room temperature.
