Deformation induced twinning in hcp/bcc Al₁₀Hf₂₅Nb₅Sc₁₀Ti₂₅Zr₂₅ high entropy alloy - microstructure and mechanical properties

Abstract

High-entropy alloys of hexagonal structure commonly revealing high strength but very limited ductility, still remain a challenging task. Advanced strategy is proposed in present work in order to develop high-entropy alloy of chemical composition Al₁₀Hf₂₅Nb₅Sc₁₀Ti₂₅Zr₂₅ at.%. Crystallographic features and microstructures of as-cast and annealed Al₁₀Hf₂₅Nb₅Sc₁₀Ti₂₅Zr₂₅ at.% alloy are characterized by X-ray diffraction, scanning and highresolution transmission electron microscopies, whereas differential scanning calorimetry is used to follow temperature-induced phase transformation in the as-cast system. The cast alloy reveals microstructure containing fine orthorhombic needle-like plates within solid-solution of body-centered cubic structure. Such a dual-phase microstructure leads to enhanced combination of high strength and good ductility