Surface Microstructure of Fe3Al After Severe Plastic Deformation

Abstract

Nanocrystals were produced on the surface of Fe3Al intermetallic compound by a severe plastic deformation technology—surface mechanical attrition. The phase and grain evolutions were characterized through x-ray diffraction technology, transmission electron microscopy, and Mossbauer spectroscopy. The results show that surface grains are refined to 15 nm in average size after 60 min of attrition. The surface grains present inhomogeneity due to the nonuniform plastic deformation when the attrition time is less than 15 min. Large quantities of dislocations and tangles of dislocations are observed in those larger grains. Al8Cr5 phase forms on the surface of Fe3Al samples which have undergone attrition for less than 15 min. When the attrition time increases, the Al8Cr5 phase becomes disordered and dissolves into the matrix. In addition, disordering of Fe3Al occurs only in a very thin area during severe plastic deformation.