| Co-Investigator(Kenkyū-buntansha) |
MABUCHI Ktaumi Research Inst.of HITACHI Co.Ltd., REsearch Engineer, 日立研究所, 研究員
SAEKI Isao Graduate School of Engineering, Hokkaido University, Inst., 大学院・工学研究科, 助手 (50235090)
TAMURA Hiroki Graduate School of Engineering, Hokkaido University, Asso.Pro., 大学院・工学研究科, 助教授 (10002023)
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| Research Abstract |
1. Preparation of (La, M ^U) (Cr, Mn) O_<3-delta> [M ^U=Ca, Sr] Oxide Films By the ultrasonic spray pyrolysis, thin (La, M ^U) (Cr, Mn) O_<3-zeta> [M ^U=Ca. Sr] oxide films were formed on substrates. This technique permitted to control film thickness and composition. The substitution of Ca and Mn resulted in an increase of electrical conductivity in contrast with a decrease by the Sr-substitution.
2. The Photoelectrochemical Behavior of Mixed Oxide Films of Titanium Oxide and Tungsten Oxide : TiO2-W03 films were formed at 1073 and 1173K on Ti plate by oxidation of W deposited on the plate. The photoelectrochemical currents increased with the W-content and with the oxidation temperature. This increase was due to a homogeneous distribution of W in) depth direction in the film.
3. Oxidation Behavior of Type43O Stainless Steel in the Initial Stage at High Temperatures : The stainless steels are recently used as the high temperature structural material. However, the accidental rapid oxidation
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, which is called as "Break Away Oxidation" occurs to result in a difficulty in use. From SEM, XPS and XRD studies, that Break Away Oxidation was found to depend on properties of the protective oxide film formed at the initial oxidation stage and the properties is determined by alloy composition, oxygen pressure and heating rate to high temperatures.
4. Formation of Corrosion Resistant Oxide Films on Aluminum by a Two Step Anodizing Process : Two step anodizing, I .treatment with chromic/phosphate solution and II. anodizing in a sulphuric acid solution, forms porous composite oxide film containing Cr (III) and phosphate ion. This film showed an increasing corrosion resistance and hardness.
5. Acid-Base Property of Surface Hydroxyl Sites of Metal Oxide Particles : The surface oxide ions on metal oxide are hydroxidized to form acid- and base-hydroxide. The method evaluating the surface hydroxide density was established for AI_2O_3, Fe_2O_3, Fe_2O_4, TiO_2, and MnO_2. On the basis of the modeling of dissociation reaction of the acid- and base-hydroxide, the dissociation constants of the hydroxides were determined and ion exchange behavior of Li, Na, K,Cs, Ni, Zn, Co, Mn, Cu, and Pb ions was explained. Less
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