Atomic scale understanding of the mutual transformations of 2H, 4H, 12R and 3C structures in face-centered cubic zirconium

Mechanisms of the mutual transformations of 2H, 4H, 12R and 3C structures were investigated in forged Zircaloy-4. Results revealed that 2H→4H→3C transformations occurred via the gliding of two neighboring 1 3 [ 1 ¯ 010 ] Shockley partials with the opposite Burgers vectors in 2H structure and the same Burgers vectors in 4H structure on every four (0001) _2H atomic layers. The 4H→12R and 2H→12R transformations were accompanied by simultaneous activity of 1 3 [ 1 ¯ 010 ] Shockley partial on every four atomic layers of the 4H and 2H structure, respectively. Moreover, the collective gliding of 1 6 [ 1 ¯ 1 ¯ 2 ¯ ] Shockley partial on every four ( 1 ¯ 1 ¯ 1 ) planes resulted in the 12R→3C transformations.