Ultra-high speed in-situ ellipso-microscopic observation of heterogeneous surface change of high-corrosion resistant material

2014 Fiscal Year Final Research Report

• Project/Area Number: 25630288
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Composite materials/Surface and interface engineering
• Research Institution: Hokkaido University
• Principal Investigator: FUSHIMI Koji 北海道大学, 工学(系)研究科(研究院), 准教授 (20271645)
• Project Period (FY): 2013-04-01 – 2015-03-31
• Keywords: 材料加工・処理 / 表面・界面物性 / 不働態

Outline of Final Research Achievements

In order to identify the initiation site of local corrosion, a visualization method of passive film with an excellent time resolution was developed. A heterogeneous formation of passive film on titanium during potentiodynamic anodic polarization in sulfuric acid, depending on substrate crystallographic orientation, and an initiation process of local breakdown of passive film in the acid containing with bromide ions were successfully observed by using the developed method. Furthermore, an ultra-violet light irradiation during the anodic polarization resulted the thinning of anodic oxide film and heterogeneous degradation of the film. In the initial period, however, the irradiation led to increase in charge transfer resistance through the film and to improve the corrosion resistance.

Free Research Field

腐食防食科学