Phase transformation mechanism and magnetic properties of Sm-Fe alloys produced by melt-spinning and high-energy ball milling

•The optimum ball-milling time is 3–5 h to obtain amorphous alloy.•The theory of the energy barrier and schematic diagram of atomic arrangement were adopted to interpret the amorphization and crystallization mechanisms.•The uniform microstructure was obtained by annealed at 700 ℃ for 20 min.•The coercivity (Hcj) and the remanence (Br) are increased by 1.28 kOe and 23.6 emu/g, respectively.