Development of High corrosion-resistant electrodeposited composite films with fine active metals from Dispersed-Particle-Free Solution

2016 Fiscal Year Final Research Report

• Project/Area Number: 26289274
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Material processing/Microstructural control engineering
• Research Institution: Kyushu University
• Principal Investigator: NAKANO Hiroaki 九州大学, 工学(系)研究科(研究院), 教授 (70325504)
• Co-Investigator(Kenkyū-buntansha): 大上 悟 九州大学, 工学(系)研究科(研究院), 助教 (90264085)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 電析 / 亜鉛 / ジルコニウム酸化物 / 分極曲線 / 複合酸化物 / 耐食性 / 腐食電流 / 微小アンチモン電極

Outline of Final Research Achievements

Electrodeposition of Zn-Zr oxide composite from an unagitated sulfate solution containing Zn2+ and Zr ions was investigated. The Zr content was higher in deposits formed from the solution at pH 2 than in those formed from the solution at pH 1 and, when the current density was increased, the Zr content in the deposits increased. The pH in the vicinity of the cathode, as measured using an Sb microelectrode, was approximately 2.2, which is similar to the critical pH for the formation of ZrO2. Scanning electron microscopy and energy-dispersive X-ray spectroscopy point analysis of the deposits revealed that granular Zr oxide was deposited at the surfaces of the Zn platelet crystals and in the voids between the crystals. Polarization curves in 3 mass% NaCl solution revealed that the corrosion potential of the deposited Zn－1.1 mass% Zr oxide films was more noble than that of Zn films and that the corrosion current density of the Zn－1.1 mass% Zr oxide films was lower than that of Zn films.

Free Research Field

材料電気化学