Microstructure, Mechanical Properties, and Corrosion Behavior of MoNbFeCrV, MoNbFeCrTi, and MoNbFeVTi High-Entropy Alloys

Abstract

The development of high-entropy alloys (HEAs) has stimulated an ever-increasing interest from both academia and industries. In this work, three novel MoNbFeCrV, MoNbFeCrTi, and MoNbFeVTi HEAs containing low thermal neutron absorption cross section elements were prepared by vacuum arc melting. The microstructure, mechanical properties, and corrosion behaviors were investigated. A dominant body-centered cubic (BCC) phase was present in all these three HEAs. In addition, an ordered Laves phase was found to be another major phase in both MoNbFeCrV and MoNbFeCrTi alloys, whereas an ordered BCC (B2) phase was observed in the MoNbFeVTi alloy. The phase formation in these three alloys was discussed. It is found that the formation of the secondary phase in these alloys is mainly ascribed to the large atomic size difference and electronegativity difference. All the three HEAs show high hardness, high yield strength but limited plasticity. Moreover, the MoNbFeCrV, MoNbFeCrTi and MoNbFeVTi alloys exhibit excellent corrosion resistance in both deaerated 1 mol/L NaCl and 0.5 mol/L H2SO4 solutions at room temperature. However, further composition adjustment and/or thermomechanical processing is required to enhance the mechanical properties of the three alloys.