X-ray diffraction and Mössbauer spectrometry studies of the mechanically alloyed Fe–6P–1.7C powders

Nanostructured Fe–6P–1.7C powders were obtained by mechanical alloying in a planetary ball mill. Morphological, microstructural and structural changes during the milling process were followed by scanning electron microscopy, X-ray diffraction and 57Fe Mössbauer spectrometry. The crystallite size refinement to the nanometer scale (5–8) nm is accompanied by an increase in the internal strain. The nanocrystalline structure distortion is evidenced by the lattice parameter changes of the milling products. The hexagonal Fe2P phosphide is formed within 6 h of milling, while the tetragonal Fe3P and orthorhombic Fe3C phases appear after 12 h of milling. A mixture of Fe3P phosphide, Fe3C carbide and α-Fe(C, P) solid solution is obtained on further milling time.