Microstructure control of metal-oxide composite materials by internal oxidation and its application to new materials processing

2018 Fiscal Year Final Research Report

• Project/Area Number: 16H04544
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Metal making/Resorce production engineering
• Research Institution: Kyoto Gakuen University (2018); The University of Tokyo (2016-2017)
• Principal Investigator: MAEDA Masafumi 京都学園大学, 研究・連携支援センター, 教授 (70143386)
• Co-Investigator(Kenkyū-buntansha): 佐々木 秀顕 愛媛大学, 理工学研究科(工学系), 講師 (10581746)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 内部酸化 / 電気化学

Outline of Final Research Achievements

Ag alloys in which SnO2 fine particles are dispersed are used as electric contact materials, and such alloys are synthesized by an internal oxidation of Ag-Sn alloys. The internal oxidation can be promoted by an addition of another element such as In and Bi. However, there is an incomplete understanding about the mechanism of the promotion and a quantitative evaluation of the oxidation rate is needed. This study applied electrochemical techniques to examination of the internal oxidation by using a solid electrolyte, and observed an internal oxidation of Ag-Sn alloys promoted by addition of Bi.

Free Research Field

金属生産工学

Academic Significance and Societal Importance of the Research Achievements

電気自動車搭載リレー用として，高電圧，高電流に耐えられる電気接点材料が求められている．Ag 中に酸化物を分散させた複合材料は耐溶着性に優れるため，従来は接点材料として Ag-CdO 系材料が用いられ，現在は人体に有毒でない Ag-SnO2 系材料が主流である．Ag-SnO2 系接点材料の製造工程においては，高温で Ag-Sn 合金中に酸素を拡散させて内部酸化を進行させる．内部酸化を促進するために In の添加が有効と知られているが，現在は In を他の元素で代替する方法も求められている．本研究は，元素を代替した接点材料の開発において反応解析に有用となる新たな評価手法を探索するものである．