2022-Sustainable Industrial Processing Summit
SIPS2022 Volume 18 Intl. Symp on Advanced Materials, Polymers, Composite, Nanomaterials, Nanotechnologies and Manufacturing
| Editors: | F. Kongoli, F. Marquis, N. Chikhradze, T. Prikhna, M. De Campos, S. Lewis, S. Miller, S. Thomas. |
| Publisher: | Flogen Star OUTREACH |
| Publication Year: | 2022 |
| Pages: | 290 pages |
| ISBN: | 978-1-989820-68-1(CD) |
| ISSN: | 2291-1227 (Metals and Materials Processing in a Clean Environment Series) |
CD shopping page
Effect of Atmosphere on the Preparation of Self-oxidized Film on Zirconium Plate
Rio Takemura1; Shinya Enomoto2; Kazuya Sasaki1; Masatoshi Kondo3; Eiki Niwa4;1GRADUATE SCHOOL OF SCIENCE AND TECHNOLOGY, HIROSAKI UNIVERSITY, Hirosaki, Japan; 2DEPARTMENT OF SCIENCE AND TECHNOLOGY, HIROSAKI UNIVERSITY, Hirosaki, Japan; 3TOKYO INSTITUTE OF TECHNOLOGY, INSTITUTE OF INNOVATIVE RESEARCH, LABORATORY FOR ADVANCED NUCLEAR ENERGY, Meguro, Japan; 4GRADUATE SCHOOL OF ENGINEERING, MIE UNIVERSITY, Tsu, Japan;
Type of Paper: Regular
Id Paper: 67
Topic: 43
Abstract:
The development of structural materials for plasma facing components such as divertors in thermonuclear fusion reactors, which are being researched for practical application around 2050, is urgently needed. When metallic zirconium is used for the plasma facing surface and blanket of a divertor for thermonuclear fusion reactor using liquid metal [1][2], zirconium oxide film is coated as a corrosion resistant film and has excellent compatibility with liquid metal during operation. To give the film high fracture resistance, it is necessary to make it densely. The self-oxidation, in which the metal surface is kept under a controlled oxygen atmosphere at high-temperature, is one of the promising method to prepare oxide films.
The purpose of this study is to elucidate the effect of atmospheric gas species on the film formation mechanism and microstructure by forming oxide films by self-oxidation in dry oxygen gas or a mixed gas of water vapor and nitrogen.
The rate of temperature increase/decrease, holding temperature, and holding time for film forming conditions were 5 °C/h, 500 °C, and 10-100 h, respectively. The atmosphere was controlled by flowing an enough 3% H2O/97% N2 or dry O2. The prepared samples were analyzed by SEM/EDS or XRD analysis.
In the oxide film prepared in a dry oxygen atmosphere, only a short crack with a width of about 0.2 µⅿ was generated in the film in the direction parallel to the interface between the oxide film and the metal. On the other hand, in the case of the mixed gas of water vapor and nitrogen, in addition to short cracks, long cracks with a width of about 0.4 µⅿ also generated. In the XRD analysis, the diffraction peak of the oxide film prepared in the mixed gas of water vapor and nitrogen was shifted to the lower angle side than that of the oxide film prepared in the dry oxygen atmosphere.
When zirconium is oxidized in an atmosphere containing steam vapor, hydrogen is generated in addition to zirconium oxide. Therefore, it was suggested that the elongation of the crystal lattice is due to solidification of hydrogen as interstitial atoms and that the resulting strain is the cause of large cracks.
Keywords:
Nuclear energy;References:
[1] Masatoshi KONDO, IOP Conf. Series: Earth and Environmental Science 364 (2019) 012012.
[2] Masatoshi KONDO, Reference Module in Materials Science and Materials Engineering, Elsevier inc. , 2020.