preparation of oxidation-resistant coating having diffusion barrier by molten salt electrodeposition and self-organization

2017 Fiscal Year Final Research Report

• Project/Area Number: 26420695
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Composite materials/Surface and interface engineering
• Research Institution: Akita University
• Principal Investigator: HARA Motoi 秋田大学, 理工学研究科, 教授 (50156494)
• Co-Investigator(Kenkyū-buntansha): 福本 倫久 秋田大学, 理工学研究科, 准教授 (20343064)
• Research Collaborator: SATO Naka
• Project Period (FY): 2014-04-01 – 2018-03-31
• Keywords: コーティング / 耐酸化性 / 電析 / 溶融塩 / ニッケルアルミナイド / 拡散障壁 / 自己組織化

Outline of Final Research Achievements

A bilayer coating consisting of Ni-aluminide and Ni-Hf alloy layers was prepared on Ni-Cr-Al alloy in four electrodeposition steps of Ni, Hf, Ni and Al. The cyclic oxidation resistance of the bilayer coating sample at 1373 K was examined with that of a single Ni-aluminide coating sample. The oxidation rate of the bilayer coating sample was lower than that of the single coating sample. A decrease in Al concentration in the Ni-aluminide layer for the bilayer coating sample during the cyclic oxidation was smaller than that for the single coating sample. This seems to result from a barrier effect of the Ni-Hf alloy layer against Al diffusion. An alumina scale formed on the bilayer coating showed a pegging morphology. This morphology led to improvement of the adherence of the scale.

Free Research Field

材料工学