Effects of Applied Load on Formation and Reorientation of Zirconium Hydrides: A Multiphase Field Modeling Study

TL;DR

This study uses multiphase field modeling to investigate how applied load influences the formation and reorientation of zirconium hydrides, revealing that neighboring hydrides significantly lower the load needed for reorientation.

Contribution

It demonstrates that hydride clusters facilitate reorientation at loads within the elastic limit, aligning simulations with experimental observations.

Findings

Hydride reorientation occurs at ~0.02 strain in single-seed models.

Neighboring hydrides reduce reorientation load by over tenfold.

Reorientation is easier with hydride clusters within elastic limits.

Abstract

The effects of applied load on the formation and reorientation of delta hydrides in alpha-zirconium matrix are studied by a multiphase field model. Simulations with only one hydride seed indicate that the hydride reorientation occurs only when a tensile or compressive strain of ~0.02 is applied along [112-0] (hoop or circumferential direction) or [0001] (radial direction aligned with the basal pole direction), respectively. However, two-seed and multi-seed hydride simulations show the significant influence of neighboring hydrides on the required load for reorientation, reducing it by more than one order of magnitude and making it comparable to the experimental results. Through phase-field simulations, this work suggests that the hydride reorientation happens more easily when clusters of hydrides are present, and the required external load for reorientation is within the elastic limit of the cladding material.