Lattice distortion and order-disorder phase equilibrium in hcp high-entropy alloys Al-Sc-Ti-Zr-Hf

High entropy alloys (HEA) have been noted for their outstanding mechanical properties as well as outwardly simple crystal structures, which offer in fact many possibilities for tuning mechanical properties through lattice distortions and short-range order. With recent reviews lamenting a lack of detailed crystal structure data, especially at the local scale, this experiment plans to investigate a recently developed refractory HEA and its precursors. High resolution powder diffraction will help determining the phases across its binary, ternary, quinary compositions and, through microstructure analysis, studying the local strain fields that are key to alloy strengthening mechanisms. Distortion and sublattice ordering will be also characterised at the atomic and nano scale by pair-distribution function analysis (PDF).