[3D13-16] Zircalloy

[3D13] In-situ TEM observation of the dissolution and re-precipitation behavior of hydrides in Zircaloy-4

*Simian Liu^1,2, Huilong Yang¹, Sho Kano¹, Hiroaki Abe¹ (1. UTokyo, 2. Xi'an Jiaotong Univ)

Keywords:Zircaloy-4, hydride, dissolution, precipitation, in situ observation

This work presents delta hydride dissolution and re-precipitation behaviors in Zircaloy-4 by in-situ heating and cooling observation in the transmission electron microscope (TEM). The hydride dissolves in the range of 473-673 K, depending on the hydrogen content. A dislocation loop is left nearby where the hydride finally disappears. The re-precipitated hydrides, normally exhibit a different growth direction from the original ones, preferentially nucleate nearby the dislocation loop during fast cooling.