Quantitative EELS analysis of zirconium alloy metal/oxide interfaces

Area of Science:

• Materials Science
• Nuclear Engineering
• Surface Science

Background:

• Zirconium alloys are critical for nuclear reactor fuel cladding.
• Waterside corrosion limits fuel burn-up and operational lifespan.
• Understanding the metal/oxide interface is key to mitigating corrosion.

Purpose of the Study:

• To reliably quantify oxygen at the metal/oxide interface in zirconium alloys.
• To investigate the influence of oxidation conditions on interface composition.
• To identify factors affecting zirconium alloy corrosion resistance.

Main Methods:

• Electron Energy Loss Spectrometry (EELS) for oxygen quantification.
• Transmission Electron Microscopy (TEM) sample preparation.
• Recalibration of EELS data against a ZrO₂ standard.

Main Results:

• Reliable oxygen quantification at the metal/oxide interface is demonstrated.
• Systematic differences in oxygen profiles were observed across various zirconium alloys.
• A sub-stoichiometric oxide (suboxide) layer was detected under slow oxidation conditions.

Conclusions:

• EELS is a viable technique for analyzing zirconium alloy oxidation.
• The presence of a suboxide layer correlates with slower oxidation rates.
• Alloy composition and oxidation behavior transitions influence corrosion resistance.