Al_0.5TiZrPdCuNi High-Entropy (H-E) Alloy Developed through Ti₂₀Zr₂₀Pd₂₀Cu₂₀Ni₂₀ H-E Glassy Alloy Comprising Inter-Transition Metals

Abstract

An Al_0.5TiZrPdCuNi high-entropy (H-E) alloy with a bcc single phase was found through a Ti₂₀Zr₂₀Pd₂₀Cu₂₀Ni₂₀ H-E glassy alloy designed based on equi-atomicity inherent to H-E alloys. The constituent elements and the composition of the Ti₂₀Zr₂₀Pd₂₀Cu₂₀Ni₂₀ alloy were determined by regarding a binary Cu₆₄Zr₃₆ bulk metallic glass as Cu₆₀Zr₄₀ alloy and subsequent replacements of the Cu and Zr atoms with other late- and early-transition metals, respectively. The Ti₂₀Zr₂₀Pd₂₀Cu₂₀Ni₂₀ alloy in a ribbon shape forms into a glassy single phase. The addition of 0.5Al to the Ti₂₀Zr₂₀Pd₂₀Cu₂₀Ni₂₀ H-E glassy alloy resulted in forming a bcc single phase for a rod specimen with a diameter of 1.5 mm. The analysis revealed that the Al_0.5TiZrPdCuNi H-E alloy is characterized by mixing enthalpy of −46.7 kJ·mol⁻¹ and Delta parameter of 8.8, which are considerably larger and negative for the former and larger for the latter against the conventional H-E alloys.