Effect of Ge addition to Si 50–55Al 25–20Fe 10Ni 5Cr 5Zr 5 alloys obtained by melt spinning

Abstract

Microstructure of Si 50-55Al 25-20Fe 10Ni 5Cr 5Zr 5 alloys obtained by rapid solidification changes from homogeneously amorphous to heterogeneous — amorphous+c-Ge (c-Ge: crystalline Ge solid solution) by the addition of Ge. The size, volume fraction and composition of c-Ge particles depend on Ge concentration in the alloy. Fine particles, with a size less than 10 nm, were obtained at 7–10 at.% Ge. Small size and homogeneous distribution of c-Ge particles argue for homogeneous nucleation from the melt during rapid solidification. The Si 5545Al 20Fe 10Ni 5Cr 5Zr 5Geo-10 alloys are characterized by high values of hardness (935–1085 H v) and electrical resistivity(11.0–12.6 μΩm). The exclusion of Ge from the amorphous phase resulted from the complicated interaction between constituent elements when weak bonding nature among Ge, Al and TM (TM-transition metals) atoms is obscured by strong attractive interaction among Si, Al and TM atoms.