Design of oxygen-doped TiZrHfNbTa refractory high entropy alloys with enhanced strength and ductility

2022-11-01
Iroc, L.K.
Tukac, O.U.
Tanrisevdi, B.B.
El-Atwani, O.
Tunes, M.A.
Kalay, Yunus Eren
Aydoğan Güngör, Eda
© 2022Refractory high entropy alloys (RHEAs) are considered promising materials for high-temperature applications due to their thermal stability and high-temperature mechanical properties. However, most RHEAs have high density (>10 g/cm3) and exhibit limited ductility at low temperatures and softening at high temperatures. In this study, we show that oxygen-doping can be used as a new alloy design strategy for tailoring the mechanical behavior of the TiZrHfNbTa alloy: a novel low-density (7.98 g/cm3) ductile RHEA. Even though the material is a single-phase BCC with some oxides at room temperature, secondary BCC and HCP nano-lamellar structures start to form above 600 °C in addition to the nano-twins which are shown to be stable up to 1000 °C. This alloy shows superior strength and compressive ductility due to the nanoengineered microstructure. The present study sheds light on tailoring the strength-ductility balance in RHEAs by controlling the microstructure of novel RHEAs at the nanoscale via oxygen-doping.
Materials and Design

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Citation Formats
L. K. Iroc et al., “Design of oxygen-doped TiZrHfNbTa refractory high entropy alloys with enhanced strength and ductility,” Materials and Design, vol. 223, pp. 0–0, 2022, Accessed: 00, 2022. [Online]. Available: https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85139850041&origin=inward.