Influence of the Al–Zr–Y master alloy composition on modification effect of Al–4% Cu alloy

E. A. Popova, P. V. Kotenkov

ABSTRACT:

Results of Al–4% Cu alloy modifying by experimental master alloys Al–1.04% Zr–0.70% Y and Al–1.23% Zr–0.39% Y are presented. The relation of Zr and Y atomic percents in these master alloys was 1.41 and 3.08, respectively.  The grain refinement of Al–4% Cu alloy by small (0.1–0.3%) additive compound Zr and/or Y with experimental master alloys or commercial binary one was studied. The structure of an initial alloy is characterized by the directional crystallization α-phase. With increasing the additive compounds (Zr + Y) the columnar zone decreases and  the equiaxed zone as well. When additive compounds are 0.326% (Zr + Y) only the equiaxed zone (~200 μm) takes place. But when the additive compounds Zr and Y are introduced into Al–4% Cu alloy with commercial binary master alloys, only columnar zone takes place.

KEYWORDS:

 aluminum alloys, primary and secondary aluminides, cubic and tetragonal lattices, structural type, transition metals, ternary master alloys, refining grain, dispersion hardening