Microstructure and mechanical property of NbTaTiV refractory high-entropy alloy with different Y2O3 contents

In this study, NbTaTiV refractory high-entropy alloys (RHEAs) reinforced with dispersed oxides were successfully designed and fabricated by mechanical alloying and subsequent spark plasma sintering (SPS). The effects of Y2O3 content on the microstructure and mechanical properties have been systematically studied. The results show that the oxide dispersion strengthening (ODS) RHEAs are mainly composed of body centered cubic (BCC) matrix and multiscale oxides, including submicron Ti-(N, O) particles, nano-sized Y-Ti-O particles and nano-sized Y2O3 particles. The ODS-RHEAs have excellent mechanical properties due to the multiscale oxides. With the content of Y2O3 increasing from 1 wt% to 3 wt% Y2O3, the compressive yield strength of the ODS-RHEAs significantly increases from 1528 to 1866 MPa, while the fracture strain slightly reduces from 22% to 16%. The enhancement of the mechanical property is mainly attributed to the increased amount of multiscale oxide particles and the refined grain structure.Graphical abstract