Preparation and properties of CoFeMoPB bulk metallic glasses

A new series of Co71-xFexMo9P14B6 (x = 0, 18, 35.5, 53 and 71 at. %) bulk metallic glasses (BMGs) have been prepared by combining fluxing treatment and J-quenching technique. The critical diameter for fully glass formation (Dmax) of the present CoFeMoPB BMGs shows a complicated change with composition, and reaches the largest value of 4.5 mm for the Fe-free alloy. The present CoFeMoPB BMGs exhibit good soft magnetic properties with the saturation magnetization of 0.18-0.71 T. The compression test shows that the present CoFeMoPB BMGs show relatively high fracture strength of 2.77-2.96 GPa, and the Co-rich BMGs (x = 0-35.5) show poor compressive plasticity while the Fe-rich BMGs (x = 53-71) exhibit significant plasticity up to 9.8% and 15.4%.