Synthesis, characterization and amorphization of mechanically alloyed Fe 75 Si 12 Ti 6 B 7 and Fe 73 Si 15 Ti 5 B 7 powders

In this study, Fe 75 Si 12 Ti 6 B 7 and Fe 73 Si 15 Ti 5 B 7 (wt. %) alloy powders were synthesized from pure elemental powders by a mechanical alloying (MA) method under argon atmosphere. The evolution in particles morphology, chemical composition, crystalline structure, magnetic and hyperfine proprieties of the mixture elements during MA(0–80 h) was investigated by scanning electron microscopy attached with energy-dispersive spectroscopy, X-ray diffraction (XRD), vibrating sample magnetometer and Mössbauer spectroscopy (MS). The Rietveld refinement of the XRD pattern of the samples milled 5 h shows the formation of several structures: Fe 3 Si, α -Fe nanostructured, Fe 2 Ti and Fe 2 B, in addition, that the structure became much more amorphous together with increasing milling time at 80 h. The thermal stability of powders milled was characterized by differential scanning calorimetry (DSC). The annealing of samples milled 80 h shows that the crystallization of the amorphous phases and the activation energy determined by using Kissinger's equation was 462.23 ± 16.11 kJ mol −1 and 798.43 ± 16.12 kJ mol −1 for the Fe 73 Si 15 Ti 5 B 7 and Fe 75 Si 12 Ti 6 B 7 , respectively. Moreover, the results from XRD and DSC for 80 h of milling were approved by the Mössbauer spectroscopy, and the spectra revealed that the sample Fe 73 Si 15 Ti 5 B 7 is fully amorphous, but the sample Fe 75 Si 12 Ti 6 B 7 still contains some of Fe with a 2.8% fraction non- detected by XRD. The saturation magnetization (Ms) and coercivity values were of about 151 emu/g, 38.5 G for Fe 73 Si 15 Ti 5 B 7 and 171.6 emu/g, 35 G for Fe 75 Si 12 Ti 6 B 7 , respectively, after 80 h of milling.