Interaction of face-centered cubic phase and twin in Zr–1.0Sn–1.0Nb–0.3Fe alloy

The thermally induced face-centered cubic (FCC) phase and its interactive interface with { 10 1 ¯ 1 } twin in Zr–1.0Sn–1.0Nb–0.3Fe alloy were characterized via transmission electron microscopy. The FCC-Zr phase and the matrix have a B-type orientation relationship, however, the interface deviates from the ( 0001 ) HCP habit plane. Moreover, the FCC-Zr phase and the twin follow Py-type orientation relationship, namely < 1 2 ¯ 10 > HCP / / < 1 1 ¯ 0 > FCC and { 10 1 ¯ 1 } HCP / / { 111 } FCC , which may be attributed to expansion and shuffling adjustment. Although the Py-type orientation relationship between the hexagonal close-packed and the FCC phases in Zr is rarely observed, due to the large crystal plane mismatch, this study provides intuitive evidence of this relationship.