Stress-induced C14 -> C15 phase transformation in a Zr(Fe,Cr)(2) Laves structured nanophase

摘要

The C14 (hexagonal close-packed) and C15 (face-centred cubic) close-packed structures are found to coexist in an individual Zr(Fe,Cr)(2) Laves structured nanophase in Zircaloy-4 alloy with shear deformation. The orientation relationship between C15 and C14 is [(1) over bar 10](C15)//[11 (2) over bar 20](C14) and ((1) over bar 11)(C15)//(0001)(C14). The stacking faults (SFs) in the C15 structure and the high-density SFs between C15 and C14 have been identified using transmission electron microscopy, which showed they originated on close-packed planes by emission of 1/6h <(2) over bar(1) over bar(1) over bar > Shockley partial dislocations from the phase boundary. Furthermore, the stress-induced C14 -> C15 phase transformation took place during the shear deformation.