Microstructure characteristics and mechanical properties of Hf0.5Mo0.5NbTiZr refractory high entropy alloy with Cr addition

Abstract This paper reported the effect of Cr addition on microstructure, phase constitutes and mechanical properties of the Hf0.5Mo0.5NbTiZr refractory high-entropy alloy. The CrxHf0.5Mo0.5NbTiZr (x = 0.1, 0.2, 0.3, 0.4 and 0.5) alloys were composed of one BCC solid solution phase and one CrMoZr-typed Laves phase. This alloy system exhibited the typical dendritic structure after casting. The dendritic structure was refined with the Cr addition. The strength of CrxHf0.5Mo0.5NbTiZr alloys increased and the plasticity also was improved with small amount addition of Cr elements, the strength continued to increase while the plasticity decreased as the concentration of Cr element increased. The homogenization treatment promoted more formation of Laves phase, which significantly increased the strength.