Optimizing glass formation in ferromagnetic alloys through chemical fluxing

Abstract

We identify a reduction reaction of boron oxide by Si during melt fluxing of the Fe-Co-Si-B-P system, which results in an unexpected and significant B enrichment and Si depletion in the alloy. Taking this reaction into account, an optimized Fe-Co-Si-B-P alloy free from oxide inclusions and demonstrating a global peak in glass forming ability is formed. Following a 22-h high temperature fluxing of the melt, alloy with composition Fe_(57.5)Co_(20.2)Si_(10.2)B_(2.1)P_(10) transforms to Fe_(57)Co_(19.2)Si_(6.8)B_(7.4)P_(9.6), and its critical rod diameter increases from 1 mm to 5 mm. The alloy also demonstrates excellent soft ferromagnetic performance characterized by a magnetic saturation of 1.53 T.

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