Abstract
A dense and uniform Cr coating was fabricated on the zirconium alloys fuel claddings by radio frequency (RF) magnetron sputtering to improve the mechanical and anti-oxidation properties under 1200 °C steam environment. The phase composition and the micro and macro morphologies of the specimens were investigated by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), scanning electron microscope (SEM) and optical-microtopography (OM) analyses, and the high-temperature oxidation behavior was evaluated at 1200 °C steam environment for 3000 s. In this paper, there exists a positive correlation between thickness and Vickers hardness (HV), and a negative correlation between surface roughness and bonding force. Radial tensile was introduced to investigate the deformation-resistant performance, and the displacement of the Cr-coated specimen was as low as 2.32 mm, which was much lower than the uncoated zircaloy cladding (3.05 mm). Different thicknesses of Cr coatings were deposited to investigate the oxidation degrees of zircaloy cladding under a high-temperature steam environment. The optimal 6 μm Cr-coated zirconium alloys cladding exhibited an excellent anti-oxidation property, and the weight gain was as low as ~4.12 mg/cm2, which was almost one-third of the uncoated specimen.
Highlights
The international community has achieved a broad consensus that the influence of the nuclear accident has been borderless since the Fukushima event
Our preliminary experiments revealed that the grain size of Cr coating decreased with the increase of sputtering pressure, and the Cr coatings with the smallest average grain sizes were obtained under pressure between 1.5 and 1.8 Pa
The peak assignments showed that Cr film was successfully deposited without any alloy phase or compound, and it was conformed to the characteristics of body-centered cubic phase of Cr (PDF card index: 06-0694)
Summary
The international community has achieved a broad consensus that the influence of the nuclear accident has been borderless since the Fukushima event. The acceleration of corrosion reactions and the generation of a large amount of hydrogen under loss-of-coolant accident (LOCA) conditions leads to mechanical property reduction of the zircaloy fuel cladding; further, the deterioration under critical boiling heat flux conditions may result in explosions in the nuclear reactor. This issue has motivated research into accident-tolerant fuels (ATFs) cladding, and a protective coating was recognized as an effective approach to increase the accident emergency rescue time [4,5]. The RF magnetron sputtering technique was chosen to deposit the Cr coatings with different thickness on the Zircalloy with different roughness by comprehensive consideration of the safety, cost and operability
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.