Critical cooling rate for the glass formation of ferromagnetic Fe_(40)Ni_(40)P_(14)B_6 alloy

摘要

Bulk ferromagnetic amorphous Fe-Ni-P-B alloys in rod shape were formed by a rapid solidification technique. The largest amorphous specimen prepared had a diameter of ～2.5 mm and the corresponding cooling rate for the glass formation of this alloy system in our experiment can be estimated to be around 492.4 K/s by the method of finite-difference numerical calculation. This value is on the same order of magnitude as the critical cooling rate R_c of Fe_(40)Ni_(40)P_(14)B_6 alloy estimated by the method of constructing the continuous-cooling-transformation (CCT) curve. It is indicated that the heterophase impurities have been eliminated well in our experiment.