A comparative study of the Fe-based amorphous alloy prepared by mechanical alloying and rapid quenching

Abstract

This paper presents a comparative study regarding the preparation of Fe-based amorphous alloys via mechanical alloying (MA) and rapid quenching (RQ). The obtained samples (powders and ribbons) were characterised by X-ray diffraction (XRD), in-situ high-temperature X-ray diffraction (HT-XRD), differential scanning calorimetry (DSC), thermogravimetry (TG) and vibrating sample magnetometry (VSM). By using elemental powders of Fe, Si and B, it was found that amorphisation cannot be achieved by dry MA or RQ. Wet MA using benzene as process control agent (PCA) led to the alloy amorphisation after 20 h of milling. It was proved that the amorphisation via wet MA is possible due to the extra amount of C atoms provided by the PCA decomposition. Using powders obtained by wet MA or a mixture of Fe, Si, B and C elemental powder, amorphous ribbons were obtained by RQ. During the amorphous samples crystallisation, a mixture of α-Fe(Si) and Fe borides is formed. The magnetic measurements showed that the magnetic characteristics of the samples are strongly influenced by the technique used for their preparation.