Structure and mechanical properties of an in situ refractory Al20Cr10Nb15Ti20V25Zr10 high entropy alloy composite

Structure, deformation behavior, and mechanical properties of a refractory Al20Cr10Nb15Ti20V25Zr10 high entropy alloy are reported. In the as-cast state, the alloy had a composite-like hypoeutectic microstructure comprised of a softer primary B2 phase and a harder eutectic mixture consisting of a C14 Laves and the B2 phases. Annealing at 1200 degrees C retained the composite-like constitution and led to the formation of a small amount of a Zr5Al3-type phase. The annealing also had a positive effect on strength and ductility of the alloy at 22 and 800 degrees C; compatibility of plastic deformation at 800 degrees C can be ascribed to the relative softness of the B2 phase. Reasonable agreement was found between the experimental structures and the results of thermodynamic modeling. (C) 2020 Elsevier B.V. All rights reserved.