Structural Evolution of Nanostructured γ-Ni-28Fe Alloy Investigated by Using the Internal Friction Technique

The structural evolution of nanostructured γ-Ni-28Fe alloy (n-Ni-Fe) (grain size d ～ 30 nm), synthesized by the mechno-chemical method, was investigated by using the internal friction technique combined with differential scanning calorimetry (DSC) in the temperature range from 300 K to 670 K. An internal friction peak with typical characteristics of the first-order phase transition was observed in the vicinity of 620 K, which corresponds to a broad exothermic process revealed by using DSC. These results can be explained as the structural changes from the disordering to the ordering transition in the n-Ni-Fe sample.