Phase transformations and microstructural properties of nanocrystalline Fe75Si10B10Nb5 alloy synthesized by mechanical alloying

Abstract

Nanostructured Fe75Si10B10Nb5 powders were prepared by mechanical alloying of Fe, Si, B and Nb elements in a high-energy planetary ball mill. The structural properties and morphology changes were investigated as a function of milling time (in the 0–100h range) by means of X-ray diffraction and scanning electron microscopy. At early stage, the dissolution of B and Si atoms into the Fe lattice leads to the formation of bcc Fe(Si,B) solid solution. After milling until 100h, a mixture of Fe(Si,B) (∼20nm) and Nb(B) (∼10nm) is obtained. On the other hand, an interesting phenomenon called mechanical recrystallization, related to the formation of a crystalline phase of a partial amorphous powder (obtained at ∼56h), was investigated.