Influence of molybdenum and silicon on the crystallization of Fe-Ni-B metallic glasses

Abstract

The modifying role of Mo and 5i on the phase relationships and microstructure of Fe-Ni-B alloys is analysed by following the crystallization behaviour of Fe₄₀Ni₄₀B₂₀, Fe₄₀Ni₃₉Mo₄B₁₂ and Fe₃₉Ni₃₉Mo₄Si₆B₁₂ glasses. The Fe₄₀Ni₄₀B₂₀ glass crystallizes simultaneously into four types of crystals namely, (A) ϒ-FeNi+orthorhombic (FeNi)₃B (eutectic), (B) ϒ-FeNi+fcc(FeNi)₂₃B₆ (eutectic), (C) ϒ-FeNi (primary) and (D) and unknown Fe-rich phase. The addition of Mo results in the primary crystallization of ϒ-FeNiMo followed by the polymorphic crystallization. Further addition of Si leads to a three stage crystallization resulting in α-Fe (primary), hexagonal Ni5Si2 (secondary) and ϒ-FeNiMo polymorphic.