Fe-Si-B amorphous alloys with high silicon concentration

Abstract

Amorphous phase formation with good ductility has been found in Fe-Si-B ternary alloys with high silicon concentration using a melt-spinning technique. The formation range of these amorphous alloys is in the range 0 to 29 at % silicon and 5 to 26 at % boron, being much wider than the previously reported range (0 to 19 at % silicon and 10 to 26 at % boron). The crystallization temperature (T x) and Vickers hardness (H v) of the Fe-Si-B amorphous alloys containing more than 19 at % silicon increase significantly with increasing boron content, while the increase in silicon content causes a decrease inT x andH v. TheT x andH v of Fe66Si28B6 alloy with the highest silicon concentration are 740 K and 500 DPN, respectively. The decreases inT x andH v with silicon content are interpreted owing to the increase in the contribution of the repulsive interaction between silicon and silicon against the attractive interactions between iron and silicon or boron. Furthermore, the silicon-rich amorphous phase has been found to crystallize by the almost simultaneous precipitation of the two equilibrium compounds of Fe3Si and Fe2B, Fe2Si0.4B0.6 or Fe4.9Si2B.