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

Research output: Contribution to journalArticleResearchpeer-review

Authors

  • L. K. Iroc
  • O. U. Tukac
  • B. B. Tanrisevdi
  • Osman El-Atwani
  • Y. E. Kalay
  • E. Aydogan

External Organisational units

  • Middle East Technical University (METU)
  • Los Alamos National Laboratory

Abstract

Refractory 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.

Details

Original languageEnglish
Article number111239
Number of pages12
JournalMaterials and Design
Volume223.2022
Issue numberNovember
DOIs
Publication statusPublished - Nov 2022
Externally publishedYes