Ternary Fe-B-C and quaternary Fe-B-C-Si amorphous alloys with glass transition and high magnetization

The ternary Fe-B-C amorphous alloys exhibit good soft magnetic properties and high saturation magnetization. The high magnetization is favorable to reduce the size of the magnetic devices. However, mass production of the Fe-B-C amorphous alloys is difficult due to their low glass-forming ability (GFA). In the present study, the various properties of the ternary Fe-B-C and quaternary Fe-B-C-Si amorphous alloys have been investigated. It has been discovered for the first time that some ternary Fe-B-C amorphous alloys with the Fe content close to that of the Cr23C6-type metastable Fe23(B, C)6 phase exhibit a glass transition prior to crystallization on heating. The alloys with the glass transition also have high mass magnetization of 176–178 A m2/kg at room temperature in as as-quenched state. As a result of attempts to improve GFA by Si addition to the Fe-B-C alloys, it has been discovered that the quaternary (Fe0.780B0.152C0.068)96Si4 and (Fe0.767B0.148C0.085)96Si4 amorphous alloys exhibit the large GFA. The large GFA of the quaternary Fe-B-C-Si alloys enables to produce thick amorphous specimens with 120 μm in thickness and with high mass magnetization of approximately 170 A m2/kg at room temperature in as as-quenched state. The ternary Fe-B-C and quaternary Fe-B-C-Si amorphous alloys with high GFA as well as high magnetization are suitable for a core material of various magnetic components. •Glass transition has been discovered in Fe-B-C amorphous alloy system.•Glass-forming ability is enhanced by addition of Si.•High magnetization as well as glass transition has been achieved.