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斉藤 淳一; Monbernier, M.*
Surfaces and Interfaces (Internet), 41, p.103248_1 - 103248_8, 2023/10
被引用回数：0 パーセンタイル：0.01(Chemistry, Physical)Contact angle is an indicator of the wettability between liquid Na and pure metals. This has been evaluated using the atomic interactions obtained from the calculations of the electronic structure of the interface. This study aims to investigate the applicability of the atomic interactions of the interface to the alloys. An interface model between Cu and Na with an alloying element was constructed, and the electronic states of the interface were calculated by the molecular orbital calculation. The bond order, which indicates the strength of the covalent bonding at the interface, and ionicity, which indicates the amount of charge transfer, were obtained as theoretical parameters from the calculation. The contact angles between the Cu or Cu alloys and liquid Na were measured using a droplet of liquid Na at 423 K in a high-purity Ar atmosphere. The contact angles of the Cu alloys were evaluated using these theoretical parameters. As a result, a correlation was obtained between the ratio of the bond order between the substrate metal atoms to the bond order between the Na atom and the substrate metal atoms and the contact angle, which is consistent with previous studies. Furthermore, for the first time, the correlation between the ionicity or difference in the ionicity and contact angle was clarified. The difference in ionicity is the difference between the ionicity of Na atoms and that of the alloying element, indicating the strength of the ionic bonding. It was suggested that Cu and Cu alloys should consider covalent and ionic bonding when evaluating wettability, because Cu has an intermediate electronic state between transition and nontransition metals. Further, it became clear that the evaluation of the contact angle using the atomic interactions at the interface are applicable not only to pure metals but also to alloys.
柴本 泰照; 与能本 泰介; 中村 秀夫; 錦沢 友俊
Proceedings of 4th Japan-Korea Symposium on Nuclear Thermal Hydraulics and Safety (NTHAS-4), p.210 - 214, 2004/11
沸騰伝熱に対する放射線誘起表面活性(RISA)の効果を検証するため、原研JMTRを用いた炉内複合照射環境下での限界熱流束(CHF)試験を計画している。試験部には直径2-mmの小口径管を採用し、伝熱面積を減ずることによって比較的低出力でCHF相当の熱流束を達成した。本試験範囲は高クオリティ下の液膜ドライアウト型CHFに分類される。計画中の炉内実験の実現可能性を確認するために、モックアップ装置を製作して炉外予備実験を行った。幾つかの技術的課題に遭遇したが、設計を改良することでそれらを解決し、安定定常二相流条件下でのCHFデータを得ることができた。得られたデータは炉内実験のデータとの比較に使用される。
斉藤 淳一; 小林 洋平*; 澁谷 秀雄*
no journal, ,
Wettability of pure metal by liquid sodium has been studied in order to control the wettability. In order to understand theoretically the wettability the electronic state of interface between liquid metal and substrate metal calculated and an atomic bonding at interface obtained. Consequently, it became clear that the contact angle which is one of indications of wettability was related with the atomic bonding at interface. An electronic state of interface between liquid low-melting temperature alloy and pure metal was calculated to evaluate the experimental results of wettability of pure metal using the low-melting temperature alloy. And the contact angle was evaluated by the atomic bonding of interface. The molecular orbital calculation was utilized for the calculation of electronic state of interface. The low-melting temperature alloy consists of bismuth, tin and indium. Aluminum, titanium, iron, nickel, copper, zirconium, niobium and molybdenum were selected as the substrate metal. From the calculation result an electronic density of state of interface was similar to that of bulk metal. It means the electronic state of interface was expressed well in this calculation. It became clear that an atomic bonding at interface changed with the atomic number of substrate metal. We will report a relationship between the atomic bonding and the contact angle of wettability in the presentation.
小林 洋平*; 斉藤 淳一; 澁谷 秀雄*
no journal, ,
Wettability is one of properties between liquid and solid material and it is very important factor affecting on acoustic property, corrosion property and so on. In this study, some experiments of wettability of pure metals were performed using the low-melting temperature alloy in order to get many fundamental information of wettability. The low-melting temperature alloy consists of bismuth, tin and indium. Aluminum, titanium, iron, nickel, copper, zirconium, niobium and molybdenum were used as a substrate metal. Test temperature was 353K and test atmosphere was in air. A droplet of the low-melting temperature alloy was put on the substrate metal and a contact angle was measured. From the measurement results, the contact angle changed depending on the substrate metal. It is suggested that the contact angle has relations with the atomic bonding between the s
斉藤 淳一; 小林 洋平*
no journal, ,
The purpose of this study deeply understands of wettability from the relationship between the contact angle and the atomic bond of the interface by using the result of theoretical calculation. As the substrate metal, nine kinds of pure metals and alloys were used. All of the contact angle were smaller than 90 degrees. It means the wettability of water with metal is good. The contact angle results have been evaluated using the bond order, which shows the strength of atomic interaction at the interface. For liquid metals and metals, the contact angle could be explained by the atomic bond at the interface. It was found that there is a good correlation between the contact angle and the atomic bond without contradictory to Young's equation even if the atomic bond at the interface is used. This suggests that it is possible to predict the wettability of an unknown metal with water.
