Study on nanocrystallization and amorphization in Fe-Cr-Mo-B-P-Si-C system during mechanical alloying

摘要

A new composition of Fe-Cr-Mo-B-P-Si-C amorphous powder was produced by mechanical alloying (MA) of elemental powder mixtures. The structure of powder particles was studied by X-ray diffractom-etry (XRD), scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). Continued milling of Fe-Cr-Mo-B-P-Si-C powder mixture first led to the formation of a Fe-base solution which transformed to the amorphous structure on further milling. It was found that the amorphization starts at the edge of particles and progresses into the internal regions as MA proceeds. Increasing milling time to 80 h yielded a fully amorphous structure. Thermal stability and crystallization characteristics of amorphous alloy were determined by means of differential scanning calorimetry (DSC), XRD and HRTEM and discussed next.