Abstract
The effect of long-term (700 h) annealing at 1000 °С on the structure and mechanical properties of the as-cast (HfCo)90(NbMo)10 and (HfCo)75(NbMo)25 (in at.%) refractory high entropy alloys was examined. The as-cast alloys consisted of a mixture of (Nb, Mo)-rich bcc and (Hf, Co)-rich B2 phases with bcc / B2 ratios close to NbMo / HfСo ratios. Annealing did not result in the formation of additional phases, which agreed with the Thermo-Calc predictions. However, annealing led to the formation of (i) B2 / bcc nanoprecipitates inside the initial bcc / B2 phases and (ii) separate Nb-rich and Mo-rich bcc phases. Annealing also caused significant strengthening of the alloys; for example, the room-temperature yield strength of the (HfCo)90(NbMo)10 alloy increased from 640 to 1340 MPa. Hardening was induced by the bcc nanoprecipitates in the B2 phase according to the Orowan mechanism. The results obtained suggest novel routes for the development of refractory high entropy alloys with a stable bcc + B2 structure.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: International Journal of Refractory Metals and Hard Materials
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
