The Effects of Fe₂P and Fe₃P Intermediate Equilibrium Phases on Glass-Forming Ability of Fe₇₆Si₉B₁₀P₅ Bulk Metallic Glass

Abstract

The glass-forming ability (GFA) of an Fe₇₆Si₉B₁₀P₅ bulk metallic glass (BMG) was evaluated thermodynamically with commercial software, Thermo-Calc, with Fe-base database, TCFE7 by utilizing its best ability to deal with equilibrium phases. The Fe₇₆Si₉B₁₀P₅ BMG was selected because it is the simplest Fe-rich BMG belonging to Fe-metalloid type with the greatest sample dimensions. A possible reason for the presence of intermediate equilibrium phases to degrade GFA of the Fe₇₆Si₉B₁₀P₅ was discussed. The results revealed that the Fe₇₆Si₉B₁₀P₅ BMG is characterized by near eutectic composition in the Fe-rich Fe-Si-B-P quaternary system and by the simultaneous presence of Fe₃P and absence of Fe₂B phases in equilibrium at a range below the solidus- to the glass-transition temperatures. The analysis of Fe₇₆(Si,B,P)₂₄ alloys for equilibrium phases revealed that the Fe₂P phase can degrade GFA of the Fe₇₆Si₉B₁₀P₅ BMG.