Elastic Properties and Thermal Expansion Behavior of a Polycrystalline VMnFeCoNi High‐Entropy Alloy

Among the equiatomic and single‐phase face‐centered cubic high‐entropy alloys, VMnFeCoNi has the highest strength‐ductility combination reported to date. This study presents the first successful measurements of its coefficient of thermal expansion ( α ) and elastic moduli between 100 and 673 K. The temperature dependence of α (in 1/K) increases monotonically with increasing temperature and can be described by α = 18.6 × 10 −6 (392/ T )² exp(392/ T )/(exp(392/ T ) − 1)², where T is the absolute temperature. The Poisson's ratio is nearly independent of temperature and equal to 0.285. In contrast, the Young's ( E ) and shear moduli ( G ), both in GPa, decrease with increasing temperature and their variations are given by E = 203 − 0.0681 T and G = 80 − 0.0292 T .