Chemical Synthesis and Characterization of a Nanometric Fe50Ni50 Alloy

R BOLSONI; V DRAGO; ENIO LIMA JR.

São Pedro, Brasil

Workshop; I Workshop on metastable and nanostructured materials; 2001

A high-purity Fe50Ni50 alloy was synthesized by ultra rapid autocatalytic chemical reduction of the corresponding transition metal ions in an aqueous solution. The ratio of metal concentration in solution is preserved in the precipitated powder alloy and no metal segregation was observed. The alloys was characterized as a chemically and structurally disordered taenite phase with crystallite size of ~10 nm. A thermal treatment of 673 K /2 h produce a structural relaxation with a shrinkage of the XRD and Mössbauer lines and a exothermic flow in the DSC signal. At the same time, the crystallite size increases to 30 nm while the mean particle size remains the same at 180 nm.