The Addition of Boron to Melt-Spun Fe−6.5%Si Ribbons

Fe−6.5%Si has higher electrical resistivity, lower magnetocrystalline anisotropy, and lower magnetostriction than traditional Fe−3.2%Si silicon steel. The reduced iron losses of Fe−6.5%Si render it a highly favorable candidate for high-speed motors and transformers. However, large-scale production of wide Fe−6.5%Si tape by rapid solidification can be challenging mainly because of its high melting point. In this work, boron is alloyed to Fe−6.5%Si to reduce its melting temperature and interfacial energy to improve the alloy’s processability. Boron additions from 0.01 wt.% to 2.24 wt.% into Fe−6.5%Si and its effect on ribbon thickness, grain size, magnetic, and mechanical properties were studied. Minor boron alloying significantly changed the melt pool stability and wetting on the quench wheel and in turn increased the quench rate with minimum impact on the magnetic saturation and ductility. Boron addition of < 0.06 wt.% was also found beneficial to the magnetic property of the alloy by lowering both its hysteresis and eddy current losses.