Study of the Mechanical Behavior of the Hydride Blister/Rim Structure in Zircaloy-4 using in-situ Synchrotron X-ray Diffraction

TL;DR

This study uses in-situ synchrotron X-ray diffraction to analyze the mechanical response of hydride and intermetallic phases in Zircaloy-4 during tensile testing at 200°C, revealing load sharing and elastic properties.

Contribution

It provides new insights into the in-situ mechanical behavior of hydride and intermetallic phases in Zircaloy-4 using synchrotron X-ray diffraction during tensile testing.

Findings

Only the f.c.c δ-hydride phase was observed in the rim/blister structure.

The phases exhibited similar elastic modulus at 200°C.

Load partitioning occurs beyond the elastic region, quantified by von Mises analysis.

Abstract

High-energy synchrotron X-ray diffraction was utilized to study the mechanical response of the f.c.c $\delta$-hydride phase, the intermetallic precipitation with hexagonal C14 lave phase and the $\alpha$-Zr phase in the Zircaloy-4 materials with a hydride rim/blister structure near one surface of the material during in-situ uniaxial tension experiment at 200 \si{\degreeCelsius}. The f.c.c $\delta$ was the only hydride phase observed in the rim/blister structure. The conventional Rietveld refinement was applied to measure the macro-strain equivalent response of the three phases. Two regions were delineated in the applied load versus lattice strain measurement: a linear elastic strain region and region that exhibited load partitioning. Load partitioning was quantified by von Mises analysis. The three phases were observed to have similar elastic modulus at 200 \si{\degreeCelsius}.