@article{Wang:2019:10.1016/j.actamat.2019.02.042,
author = {Wang, S and Giuliani, F and Britton, TB},
doi = {10.1016/j.actamat.2019.02.042},
journal = {Acta Materialia},
pages = {76--87},
title = {Microstructure and formation mechanisms of δ-hydrides in variable grain size Zircaloy-4 studied by electron backscatter diffraction},
url = {http://dx.doi.org/10.1016/j.actamat.2019.02.042},
volume = {169},
year = {2019}
}

Download

TY  - JOUR
AB  - Microstructure and crystallography of δ phase hydrides in as-received fine grain and ‘blocky alpha’ large grain Zircaloy-4 (average grain size ∼11 μm and >200 μm, respectively) were examined using electron backscatter diffraction (EBSD). Results suggest that the matrix-hydride orientation relationship is {0001} α ||{111} δ ;<112¯0> α ||<110> δ for all the cases studied. The habit plane of intragranular hydrides and some intergranular hydrides has been found to be {101¯7} of the surrounding matrix. The morphology of intergranular hydrides can vary depending upon the angle between the grain boundary and the hydride habit plane. The misfit strain between α-Zr and δ-hydride is accommodated mainly by high density of dislocations and twin structures in the hydrides, and a mechanism of twin formation in the hydrides has been proposed. The growth of hydrides across grain boundaries is achieved through an auto-catalytic manner similar to the growth pattern of intragranular hydrides. Easy collective shear along <11¯00> makes it possible for hydride nucleation at any grain boundaries, while the process seems to favour grain boundaries with low (<40°) and high (>80°) c-axis misorientation angles. Moreover, the angle between the grain boundary and the adjacent basal planes does not influence the propensity for hydride nucleation.
AU  - Wang,S
AU  - Giuliani,F
AU  - Britton,TB
DO  - 10.1016/j.actamat.2019.02.042
EP  - 87
PY  - 2019///
SN  - 1359-6454
SP  - 76
TI  - Microstructure and formation mechanisms of δ-hydrides in variable grain size Zircaloy-4 studied by electron backscatter diffraction
T2  - Acta Materialia
UR  - http://dx.doi.org/10.1016/j.actamat.2019.02.042
UR  - http://hdl.handle.net/10044/1/69330
VL  - 169
ER  - 

Download