Characterization of Fe-Cr-Mn-N amorphous powders with a wide supercooled liquid region developed by mechanical alloying

In the present study, amorphous Fe-18Cr-4Mn-xN alloys were successfully synthesized by mechanical alloying (MA) of pure elemental powders under a nitrogen gas atmosphere. The microstructure of the milled products at different stages of milling was characterized by X-ray diffraction (XRD) and high-resolution transmission electron microscopy (TEM). Furthermore, differential scanning calorimetry (DSC) was conducted to investigate the thermal stability and to determine the glass formation ability and the crystallization behavior of the amorphous as-milled powders. The results showed that by increasing the milling time, the amorphous phase content increases and after 126 h the amorphization process becomes complete. The alloys exhibited a distinct glass transition and a wide supercooled liquid region that increased by increasing the milling time. It was found out that dissolved nitrogen atoms play a crucial role in the amorphization and the exhibition of the large supercooled liquid region.