Preparation of Crystalline Ceramic Materials by Hydrothermal Electrolytic Oxidation

水热电解氧化制备结晶陶瓷材料

• 批准号: 60470072
• 负责人: MASAHIRO YOSHIMURA
• 金额: $ 2.43万
• 依托单位: Tokyo Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1985
• 资助国家: 日本
• 起止时间: 1985 至 1986
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-60470072/
• 关键词: Hydrothermal electrolytic oxidation; Hydrothermal oxidation; Zirconia; Niobium oxide; Anodic oxidation; Fine powders; Titania; 酸化亜鉛

A new technique : hydrothermal electrolytic (anodic) oxidation, has been developped to fabricate films or fine powders of oxides by combining hydrothermal oxidation and anodic (electrolytic) oxidation techniques for metals and alloys. The results and summary are as follows:1. An autoclave, max 300゜C, 20 MPa, 980 ml with 3 inner electrodes has been fabricated.2. In the anodic oxidation of Zr under hydrothermal conditions, continuous anodized film was formed on Zr plate below 200゜C in <H_2SO_4> or Y <(NO_3)_3> solutions.3. Above 200゜C,Zr plate showed pitting and/or edge dissolution under high potential above 3 V in conc. Y <(NO_3)_3> solutions.4. The surface and the precipitates of the Zr plate were monoclinic <ZrO_2> polycrystals with the crystallite size of submicron.5. A small amount of Y was detected in the products by ESCA.The anodic oxidation of Nb plate in hydrothermal LiOH, <Li_2CO_3> and <LiNO_3> solutions gave th e results as follows:6. Passivation of Nb was established by the formation of the anodic oxide film in any conditions studied.7. The anodized films were amorphous by X-ray diffraction.8. Potentiostatic analysis at 4.5 V indicated the leakage current increased with temperature from 100゜ to 200^C but decreased at 250゜C because of the densification of the film at higher temperatures.9. In the galvanostatic anodic oxidation at 250゜C in 0.1 N- <LiNO_3> , oxide film formed in relation to the applied current in innitial stages but almost stopped after a certain period when a low current density was applied.By the hydrothermal oxidation method, the metals of Zn, Ti and Nb yielded ZrO, <TiO_2> (rutile) and monoclinic <Nb_2O_5> as the final products.

一项新技术：水热电解（阳极）氧化是将水热氧化和阳极（电解）氧化技术相结合，用于制备金属和合金的氧化物薄膜或微细粉末。主要研究结果如下：1.制作了最高温度300 ℃、压力20 MPa、容量980 ml、内电极3个的高压釜.在锆的水热阳极氧化过程中，在200 ℃以下的温度下，在钇溶液中，锆板上形成了连续的阳极氧化膜<H_2SO_4>.在浓度为Y &lt;（NO_3）_3&gt;的溶液中，在200 ° C以上，在3 V以上的高电位下，Zr板出现点蚀和/或边缘溶解。4. Zr板的表面和析出物均为单斜<ZrO_2>多晶，晶粒尺寸为亚微米级.用ESCA分析了产物中的微量Y。铌片在水热LiOH溶液中的阳极氧化<Li_2CO_3><LiNO_3>结果如下：6。通过在任何研究条件下形成阳极氧化膜来建立Nb的钝化。经X射线衍射分析，阳极氧化膜为非晶态.在4.5 V下的恒电位分析表明，从100 ° C到200 ° C，漏电流随温度增加而增加，但在250 ° C下由于膜在较高温度下的致密化而降低。在250 ℃、0.1N-的恒电流阳极氧化中<LiNO_3>，氧化膜的形成与外加电流有关，但在一定时间后，当外加电流较低时，氧化膜几乎停止.在水热氧化中，Zn、Ti和Nb金属最终生成ZrO、<TiO_2>（金红石）和单斜晶系<Nb_2O_5>.

项目成果

M. Yoshimura, H. Ohira and S. Somiya: "Hydrothermal oxidation of titanium metal" Yogyo Kyokai Shi. 93 (7). 357-363 (1985)

M. Yoshimura、H. Ohira 和 S. Somiya：“钛金属的水热氧化”Yogyo Kyokai Shi。

吉村昌弘,大平弘之,宗宮重行: 窯業協会誌. 94〔11〕. 1186-1189 (1986)

Masahiro Yoshimura、Hiroyuki Ohira、Shigeyuki Somiya：《陶瓷协会杂志》94 [11]1186-1189（1986）。

中川隆広,神野公行,吉村昌弘,宗宮重行: 窯業協会誌. 94〔11〕. 1131-1135 (1986)

Takahiro Nakakawa、Kimiyuki Jinno、Masahiro Yoshimura、Shigeyuki Somiya：陶瓷协会杂志 94 [11] 1131-1135 (1986)。

T. Nakagawa, K. Kamino, M. Yoshimura and S. Somiya: "Hydrothermal reaction sintering of Permalloy - Iron oxide composite" Yogyo Kyokai Shi. 94 (11). 1131-1135 (1986)

T. Nakakawa、K. Kamino、M. Yoshimura 和 S. Somiya：“坡莫合金-氧化铁复合材料的水热反应烧结”Yogyo Kyokai Shi。

吉村昌弘,柳承乙,春山志郎,宗宮重行: 窯業協会誌.

Masahiro Yoshimura、Seungotsu Yanagi、Shiro Haruyama、Shigeyuki Somiya：陶瓷协会杂志。