| Abstract Scope |
A B2-ordered refractory high entropy alloy (RHEA) was found to exhibit good plasticity, partially attributed to the extensive deformation twinning. The twins form almost immediately after yielding, with their density increasing as plastic strain accumulates. Microstructural and crystallographic analyses show that the B2-ordered crystal structure is retained in these twins, which form through the rotation of domains within the parent grain (matrix) about <011> or <112> axes to discrete angles that match coincidence-site lattice (CSL) relationships. Twins with rotation angles of 10.10°, 13.44°, 14.65°, 16.10°, 17.86°, 20.05°, 22.84°, 26.53°, 31.59°, and 38.94° were identified and analyzed. Twins with larger rotation angles are typically observed at higher plastic strain levels. Rotational twin formation mechanisms, consistent with the experimental observations, are proposed and discussed. |