Detecting the Oxidation of Zircaloy Claddings by Infrared Interference

NANO ◽  
2018 ◽  
Vol 13 (02) ◽  
pp. 1850015 ◽  
Author(s):  
Hongyi Mi ◽  
Solomon Mikael ◽  
Edward Swinnich ◽  
Todd Allen ◽  
Kumar Sridharan ◽  
...  
Keyword(s):  
Oxide Layer ◽  
Layer Thickness ◽  
Oscillation Amplitude ◽  
Oscillation Period ◽  
Oxide Layer Thickness ◽  
Optical Interference ◽  
Cross Sectional ◽  
Oxide Layers ◽  
Ft Ir ◽  
And Performance

As the expected life of dry cask storage installations increases, it becomes increasingly desirable to monitor the state and performance of the cask internals to ensure that they continue to safely contain the radioactive materials in the fuel. One aspect of this task is the monitoring of oxidation of the cladding. With this consideration in mind, Zircaloy-4 (Zr-4) cladding samples were exposed to air at 500[Formula: see text]C for various duration times to create thin corrosion oxide layers on the surface. The surfaces of the oxidized samples were then systematically scanned by Fourier Transform Infrared (FT-IR) spectroscopy to achieve the infrared (IR) interference spectra and study the relationship between the optical interference and the various thicknesses of the oxide layers. The profiles of the oxide layers were verified througth cross-sectional examination by Scanning Electron Microscopy. The IR interference patterns varied with oxide layer thickness, enabling the determination of oxide layer thickness of values, including half micron thick. Further analysis demonstrated that the interference oscillation period and the oscillation amplitude decreased with increasing oxide layer thickness. Combined with a physical model that describes the optical interference, the interference spectra were directly correlated to the oxide layer thickness quantitatively. The study provides the basis for an accurate, nondestructive and sensitive method to monitor the degree of zirconium-based cladding corrosion due to oxidation.

Characterization of Inhomogeneity in Thermal Oxide SiO2 Films on 4H-SiC Epitaxial Substrates by a Combination of Fourier Transform Infrared Spectroscopy and Cathodoluminescence Spectroscopy

2018 ◽  
Vol 924 ◽  
pp. 273-276 ◽  
Author(s):  
Masanobu Yoshikawa ◽  
Keiko Inoue ◽  
Junichiro Sameshima ◽  
Hirohumi Seki
Keyword(s):  
Fourier Transform ◽  
Oxide Layer ◽  
Layer Thickness ◽  
Phonon Mode ◽  
Fourier Transform Infrared ◽  
Blue Shift ◽  
Peak Frequency ◽  
Oxide Layer Thickness ◽  
Thermal Oxide ◽  
Ft Ir

We measured Fourier transform infrared (FT-IR) and cathodoluminescence (CL) spectra of SiO2 films with a various thickness, grown on 4H-SiC substrates. The peak frequency of the transverse optical (TO) phonon mode was blue-shifted by about 5 cm−1 as the oxide-layer thickness decreased from 50-60 nm to 10 nm. The blue shift of the TO mode is considerd to be caused by interfacial compressive stresses in the oxide-layer. On the other hand, the TO phonon mode was found to dramatically decrease as the oxide-layer thickness decreased from 10 nm to 1.7 nm. The CL measurement indicates that the intensity of the CL peaks at about 460 and 490 nm attributed to oxygen vacancy centers (OVCs) for No.2 become stronger than that for No.1. From a comparison between FT-IR and CL measurements, we concluded that the red-shift of the TO phonon with decreasing the oxide-layer thickness can mainly be attributed to an increase in inhomogeneity at the SiO2/SiC interface with decreasing oxide-layer thickness.

Characterization of Inhomogeneity in SiO2 Films on 4H-SiC Epitaxial Substrate by a Combination of Fourier Transform Infrared Spectroscopy and Cathodoluminescence Spectroscopy

2015 ◽  
Vol 821-823 ◽  
pp. 460-463 ◽  
Author(s):  
Masanobu Yoshikawa ◽  
Hirohumi Seki ◽  
Keiko Inoue ◽  
Takuma Kobayashi ◽  
Tsunenobu Kimoto
Keyword(s):  
Fourier Transform ◽  
Oxide Layer ◽  
Layer Thickness ◽  
Polarized Light ◽  
Fourier Transform Infrared ◽  
Peak Frequency ◽  
Oxide Layer Thickness ◽  
Phonon Modes ◽  
Surface Polaritons ◽  
Ft Ir

We measured Fourier transform infrared (FT-IR) and cathodoluminescence (CL) spectra of SiO2 films with various thicknesses, grown on 4H-SiC substrates. The appearance of broad phonon modes at ~1150–1250 cm-1 in p-polarized light and their disappearance in s-polarized light confirmed that the phonon modes at ~1150–1250 cm-1originated from surface polaritons (SPPs). For the thin SiO2 film (8-nm thick), the peak frequency of the transverse optical (TO) phonon in the SiO2 film on the 4H-SiC substrate was observed at ~1080 cm-1and was higher than that in SiO2 films on the Si substrate (1074 cm-1). This suggested that the thin SiO2 film (8-nm thick) is under compressive stresses at the interface between the SiO2 film and SiC substrate. On the other hand, for the thick SiO2 films (85 and 130-nm thick), the TO phonon peak frequency tended to shift toward lower frequencies with increasing oxide layer thickness. The CL measurement indicated that the CL peak intensity at ~640 nm, attributed to non-bridging oxidation hole centers (NBOHCs), became stronger with increasing oxide layer thickness, relative to that of the CL peaks at ~460 and 490 nm due to oxygen vacancy centers (OVCs). By comparing the FT-IR and CL measurements, we concluded that the TO phonon red-shift with increasing oxide layer thickness can mainly be attributed to an increase in inhomogeneity with increasing oxide layer thickness for the thick SiO2 films.

The possibility to control the thickness of the oxide layer on the titanium Grade 2 by mechanical activation and heat treatment

2020 ◽  
Vol 2 (100) ◽  
pp. 70-77
Author(s):  
M. Szota ◽  
A. Łukaszewicz ◽  
K. Machnik
Keyword(s):  
Heat Treatment ◽  
Mechanical Activation ◽  
Oxide Layer ◽  
Layer Thickness ◽  
Pure Titanium ◽  
Medical Application ◽  
Oxide Layer Thickness ◽  
Surface Development ◽  
Titanium Grade ◽  
Practical Implications

Purpose: The paper presents the results of microstructure, surface development and thickness of the oxide layer on the pure titanium Grade 2 after mechanical activation and heat treatment (550°C/5h). Design/methodology/approach: Studies show that it is possible to control the thickness of the oxide layer by using different materials to change the roughness of surface - mechanical activation before heat treatment. After mechanical activation and heat treatment, the results of the thickness of the oxide layer as well as a level of surface development were obtained, presented and discussed. Findings: The conducted research have proved that mechanical activation of the surface which cause increase of surface development results in greater thickness of oxide layer which is formed during heat treatment. Nevertheless mechanical activation that results in decrease of surface development, such as polishing, results in decrease of oxide layer thickness. Research limitations/implications: The conducted research have showed up that mechanical activation of the surface which cause increase of surface development results in greater thickness of oxide layer which is formed during heat treatment. Nevertheless, mechanical activation that results in decrease of surface development, such as polishing, results in decrease of oxide layer thickness. Practical implications: are possible using similar method for passivation titanium alloys for medical application. Originality/value: The paper presents the possibility of using mechanical preactivation of surface before heat treatment passivation.

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