Creative Preparation of High-oxidation Resistant Coating on Nb-base Heat-resistant Alloys using Molten-salt Electrodeposition and Self-systematization

• Project/Area Number: 23560860
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Material processing/treatments
• Research Institution: Akita University
• Principal Investigator: HARA Motoi 秋田大学, 工学(系)研究科(研究院), 教授 (50156494)
• Co-Investigator(Kenkyū-buntansha): FUKUMOTO Michihisa 秋田大学, 工学資源学研究科, 講師 (20343064)
• Project Period (FY): 2011 – 2013
• Project Status: Completed (Fiscal Year 2013)
• Budget Amount: ¥5,330,000 (Direct Cost: ¥4,100,000、Indirect Cost: ¥1,230,000); Fiscal Year 2013: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2012: ¥1,300,000 (Direct Cost: ¥1,000,000、Indirect Cost: ¥300,000); Fiscal Year 2011: ¥2,730,000 (Direct Cost: ¥2,100,000、Indirect Cost: ¥630,000)
• 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 / ニオブ基合金 / 自己組織化 / 耐酸化コーティング / 溶融塩電析 / 高温酸化 / 耐熱合金 / Nb基合金 / Niアルミナイド / アルミナ皮膜

Research Abstract

Coatings of Ni aluminide/Ni bilayer on Nb-W and Nb-W-Mo alloys were prepared by the electrodeposition of Al using a molten salt electrolyte after the Ni electrodeposition. The coating specimen with a thin Ni layer showed a vigorous oxidation during the initial period. On the contrary, the coating specimen with a thick Ni layer showed a high oxidation resistance. For the coating specimen with a thick Ni layer, intermediate layers consisting of Ni-Nb alloys were formed by the diffusion of the Ni layer and the alloy substrate during the oxidation test. These intermediate layers contributed the maintenance of a high concentration of Al in the surface layer and the suppression of spallation of the layers, leading to the improvement in the oxidation resistance of the coating.

Research Products

• [Presentation] (2014)
  • Author(s): N. Sato, M. Fuji, N. Kohiruimaki, M. Fukumoto and M. Hara
  • Organizer: International Symposium on High-Temperature Oxidation and Corrosion
  • Place of Presentation: Hakodate, Japan
• [Presentation] Prepartion of Ni Aluminide/Ni Bilayer Coating on Nb-W Alloys by Molten Salt Electrodeposition and Oxidation Resistance (2014)
  • Author(s): N. Sato, M. Fuji, N. Kohiruimaki, M. Fukimoto and M. Hara
  • Organizer: International Symposium on High-Temperature Oxidation and Corrosion 2014
  • Place of Presentation: 函館国際ホテル
• [Presentation] Nb-W合金上へのNiアルミナイド/Ni２層コーティングとその耐酸化性 (2012)
  • Author(s): 佐藤菜花，藤 雅彦，茨木 啓，福本倫久，原 基
  • Organizer: 日本金属学会2012年秋期大会（151回）
  • Place of Presentation: 愛媛大学（松山）