Creation of Oxide functional thin film with nano Scale Structure Formed by Modulated Electrolysis Process

通过调制电解工艺制备具有纳米级结构的氧化物功能薄膜

• 批准号: 09650786
• 负责人: FUJIMOTO Shinji
• 金额: $ 1.86万
• 依托单位: Osaka University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1997
• 资助国家: 日本
• 起止时间: 1997 至 1998
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09650786/
• 关键词: Passivity; Stainless Steels; Modification of Structure; Electrochemistry; Porous Films; Transmission Electron Microscope; Thin Films; Surface Finish

Extraordinarily thick and porous passive film can be obtained on austenitic stainless steels, Fe-18Cr alloy, and Ni-18Cr alloys by square wave potential pulse polarisation in hot sulphuric acid.The material was polarised in 5 kmol / m^3 H_2S0_4 solution at 50 - 80 ﾟC with applied potential modulated as square wave.The transmission electron microscopy revealed that the film consists of nano-crystalline oval-shape grains of around 1-4 nm in its size.The film has large amount of open pathways linking with each others to be penetrated easily by ions or water molecule.The film formation mechanism is classified into two processes according to the applied potentials.Electrochemical impedance and photoelectrochemical properties of the porous films were also examined.For the anodic type film, the capacitance is fairly larger than that of the substrate steel, and is nearly proportional to the total thickness of the film.On the other hand, the capacitance for the cathodic type film was almost equivalent to that of the substrate steel, and was independent of thickness, structure, and other properties.Therefore, the capacitance arised only at the substrate / solution interface, and porous structure of the thick film has no electrochemical connection with substrate.Photoelectrochemical response was measured for the anodic type film.The photo current revealed the p-type semiconductor response, and the photo current spectrum is similar to that for ordinary thin passive film formed in sulphuric acid.The photo current efficiency is fairly larger than that for thin passive film.That is, the photo current increased with increasing film thickness, revealed a maximum at the thickness of about 10 nm, then decreased.The electrochemical impedance and the phoelectrochemical response revealed that the thick porous film has various electrochemical properties depending on the structure, which is possible to be ordered by electrolysis conditions.

在奥氏体不锈钢、Fe-18 Cr合金、在50 ~ 80 ℃、5 kmol / m^3的H_2SO_4溶液中，用方波调制电位脉冲极化Ni-18 Cr合金，透射电子显微镜观察表明，薄膜由纳米晶的椭圆形晶体组成，薄膜的表面形貌为椭圆形。多孔膜的成膜机理根据所施加的电位分为两个过程，并对膜的电化学阻抗和光电化学性能进行了研究。对于阳极型膜，阴极型薄膜的电容与基体钢的电容基本相当，且与薄膜的总厚度几乎成正比，而阴极型薄膜的电容与基体钢的电容基本相当，与薄膜的厚度、结构、对阳极型膜进行了光电化学响应测试，光电流显示了p型半导体响应，其光电流谱与硫酸中形成的普通钝化膜的光电流谱相似，光电流效率比钝化膜的光电流效率大得多，即光电流随膜厚的增加而增加，电化学阻抗和光电化学响应表明，厚多孔膜具有不同的电化学性质，其结构与电解条件有关。

项目成果

S.Fujimoto,T.Shibata: "Photo Electrochemical Response of Passive Films Formed on Pure Cr and Fe-Cr Alloys in Sulphuric Acid Solution" Materials Science Forum. 289/292. 989-996 (1998)

S.Fujimoto、T.Shibata：“纯铬和铁铬合金在硫酸溶液中形成的钝化膜的光电化学响应”材料科学论坛。

S.Fujimoto,T.Shibata: "Improvement of Pitting Corrosion Resistance of Type304 Stainless Steel by Modification of Passive Film with Ultraviolet Light Irradiation" Journal of Electrochemical Society. 145・5. L79-81 (1998)

S.Fujimoto、T.Shibata：“通过紫外线照射钝化膜改善 304 型不锈钢的耐点蚀性能”，电化学会杂志 145・5（1998 年）。

藤本慎司,柴田俊夫: "鉄系金属ステンレス鋼の不働態皮膜" 表面科学. 19・12. 812-818 (1998)

Shinji Fujimoto，Toshio Shibata：“黑色金属不锈钢上的钝化膜”表面科学 19・12（1998）。

S.Fujimoto, O.Chihara, T.Shibata: "Photo Current Response of Passive Film Formed on Pure Cr and Fe-Cr Alloys in Sulphuric Acid Solution" Materials Science Forum. (発表予定). (1998)

S.Fujimoto、O.Chihara、T.Shibata：“硫酸溶液中纯铬和铁铬合金上形成的钝化膜的光电流响应”材料科学论坛（即将发表）。

藤本愼司、柴田俊夫: "ステンレス鋼の表面改質" バウンダリ-. 14・1. 4-9 (1998)

Shinji Fujimoto，Toshio Shibata：“不锈钢的表面改性”边界14・1（1998）。