| Project/Area Number |
06402051
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Material processing/treatments
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| Research Institution | TOHOKU UNIVERSITY |
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Principal Investigator |
ASAMI Katsuhiro TOHOKU UNIVERSITY,INSTITUTE FOR MATERIALS RESEARCH,ASSOCIATE PROFESSOR, 金属材料研究所, 助教授 (20005929)
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| Co-Investigator(Kenkyū-buntansha) |
AKIYAMA Eiji TOHOKU UNIVERSITY,INSTITUTE FOR MATERIALS RESEARCH,RESEARCH ASSOCIATE, 金属材料研究所, 助手 (70231834)
KIKUCHI Michio TOHOKU UNIVERSITY,INSTITUTE FOR MATERIALS RESEARCH,RESEARCH ASSOCIATE, 金属材料研究所, 助手 (30204837)
KAWASHIMA Asahi TOHOKU UNIVERSITY,INSTITUTE FOR MATERIALS RESEARCH,ASSOCIATE PROFESSOR, 金属材料研究所, 助教授 (50005964)
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| Project Period (FY) |
1994 – 1996
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| Keywords | NON-EQUILIBRIUM ALLOY / COPPER-TANTALUM ALLOY / COPPER-ZIRCONIUM ALLOY / ATMOSPHERIC OXIDATION / SUPPORTED CATALYST / CATALYST FOR DISSOCIATION OF NITROGEN MONOXIDE / COBALT-ZIRCONIUM ALLOY / ZIRCONIUM OXIDE |
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| Research Abstract |
Oxidation behavior of non-equilibrium Cu-Zr, Cu-Ta and Ni-Zr alloys and catalytic properties of Co-Zr alloys for NO direct decomposition were examined in details.
The initial surface ZrO_2 film formed on the rapidly quenched Cu-Zr alloy surface was very thin and protective, but it lost its protectiveness by reaction with moisture in atmosphere, resulting in oxidation of the alloy. The reaction with moisture developed a sandwich-structure of metallic copper layrs and ZrO_2 layrs. Two types of ZrO_2 oxide, tetragonal and monoclinic phases were formed ; the former transformes to the latter phase by reaction with the atmospheric moisture.
Cu-Ta alloys prepared by sputter-deposition were colored to various colors by exposure to an air with relative humidities of 70% at 70ﾟC for 60 hours. The color depends on the alloy composition. The topmost surface of the colored specimens consisted of metallic copper, under which oxide layr containing Ta, and the coloration depends mostly on the protectiveness of the initial oxide film.
A morphous Ni-33Zr alloy about 20mum thick showed complete preferential oxidation of Zr in air at high temperature. Nickel was oxidized after the complete Zr oxidation. The formed ZrO_2 was mainly tetragonal on high Ni alloys and monoclinic on low Ni alloys.
Treatment of amorphous Co-Zr alloys containing small amount of Pt-group elements in HF solutions followed by oxidation formed fine particles of Pt-group metals dispersed and supported on oxides and showed high activity to the decomposition reaction of NO.On the other hand, binary Co-Zr alloys had no catalytic activity to the above reaction. Among the additive Pt-group metals, palladium was most effective, and Co-Zr-Pd alloys had almost the same high catalytic activity with that of Pd-black because of synergistic action of Co_3O_4, ZrO_2 and metallic Pd for the catalytic reaction.
Amorphous Fe-Cr-P-C alloy powder of nanometer-size was also successfully formed.
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