Effect of TiN diffusion barrier on elements interdiffusion behavior of Ni/GH3535 system in LiF-NaF-KF molten salt at 700℃

Chengxu Wang^1,2，Wei Chen¹，Minghui Chen³，Demin Chen¹，Ke Yang¹，Fuhui Wang³

1. Institute of Metal Research, Chinese Academy of Sciences2. School of Materials Science and Engineering, University of Science and Technology of China3. Shenyang National Laboratory for Materials Science, Northeastern University

摘 要：A TiN interlayer with high electrical conductivity was prepared between the GH3535 alloy and the Ni coating as a diffusion barrier to elements interdiffusion with the goal of increasing the corrosion resistance of GH3535 alloy in molten FLiNaK salt at 700℃. Results indicated that Ni coating could be directly electroplated on the TiN coated GH3535 alloy without extra conductive transition layer. TiN layer showed excellent thermal and chemical stabilities at elevated temperature in this molten salt system, without phase decomposition. The Ni/TiN composite coating was stable enough to resist corrosion in LiF-NaF-KF molten salt at 700℃. Elements interdiffusion between the substrate and Ni coating could be effectively inhibited and the corrosion resistance of the alloy was greatly enhanced. Besides, the TiN interlayer remained continuous and well adhered to the Ni coating as well as the substrate after corrosion test.

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