Formation and soft magnetic properties of Co-Fe-Si-B-Nb bulk glassy alloys

Soft ferromagnetic bulk glassy alloys in Co-Fe-Si-B base system were formed it, the diameter range up to I fruit at the composition of (Co(0.705)Fe(0.045)Si(0.1)Bo(0.15))(96)Nb-4 by copper mold casting. Since no bulk glass formation has been obtained in the Co-Fe-Si-B system, the addition of 4%Nb is very effective for the increase in the glass-forming, ability. The effectiveness was interpreted by satisfaction of the three component rules for formation Of bulk glassy alloys. The bulk glassy alloys exhibit the glass transition before crystallization. The glass transition temperature (T-g), the Supercooled liquid region defined by the difference between T-g Lind crystallization temperature (T-s). DeltaT(s) (= T-g-T-g) and the reduced glass transition temperature (T-g/T-1) are 823 K, 37 K Lind 0.61, respectively. The bulk glassy alloys also exhibit soft magnetic properties with saturation magnetization (I-s) of about 0.60 T Lind low coercive force (H-c) below 3 A/m. The synthesis of the Co-based bulk glassy alloy rods with glass transition and good soft magnetic properties is important for future development as a new type of Soft Magnetic bulk material.