ABSTRACT
Using Mössbauer spectra and x-ray diffraction patterns, annealed mechanically alloyed Fe - Cu has been investigated in this paper. It is found that in [Formula: see text], after it has been milled, fcc-Cu has transformed into bcc-Cu, and some Cu atoms have diffused into the Fe. After the alloy has subsequently been annealed, it is found that bcc-Cu has transformed back into fcc-Cu, while the Cu atoms in the Fe have been separated. In [Formula: see text], after being milled, an fcc-Fe-rich phase has been formed, and after the alloy has subsequently been annealed, this has transformed back to bcc-Fe. The shorter the milling time and the higher the annealing temperature, the faster the transformation. In [Formula: see text], after it has been annealed, the fcc-Fe-rich phase has transformed to bcc-Fe also, and the fcc-Cu-rich phase remains when the annealing temperature increases. All of these results show that the fcc-Fe-rich phase in the milled samples is a metastable phase - it will transform to stable bcc-Fe when it is annealed - while the long-milling-product fcc-Cu-rich phase is a stable phase.
