Corrosion Behavior of Cu-Ni Alloy Film Fabricated by Wire-fed Additive Manufacturing in Oxic Groundwater

Gha-Young Kim^*, Jeong-Hyun Woo, Junhyuk Jang, Yang-Il Jung, Young-Ho Lee

Korea Atomic Energy Research Institute, 111, Daedeok-daero 989beon-gil, Yuseong-gu, Daejeon 34057, Republic of Korea

Received 2024-03-05 ; Revised 2024-03-25 ; Approved 2024-04-15

Abstract

As the importance of sustainable energy technologies increases, spent nuclear fuels (SNFs) needs to be managed safely and efficiently, in a way as deep geological disposal (DGD). Since DGD canister should provide a long-term isolation of SNFs from biosphere, public safety, and environmental protection, the canister material should have high corrosion resistance. In this regard, this study investigated the feasibility of a Cu-Ni film fabricated by additive manufacturing (AM) as a corrosion-resistant layer for DGD canister applications. In particular, a wire-fed AM technique was used to prepare millimeter-scale CuNi film onto carbon steel substrate. Electrochemical investigations were conducted by using aerated groundwater from the KAERI underground research tunnel (KURT) as an electrolyte with an NaCl additive to identify the oxic corrosion characteristics of the CuNi film. Findings show that the AM-CuNi film has enhanced corrosion resistance (i.e., lower corrosion current density and dense passive layer) in an NaCl-added groundwater solution. For the application to a DGD canister, more systematic research is needed to understand the microstructure performance, mechanical properties, and associated corrosion resistance in the presence of various corroding agents.

Key Words : Copper-nickel film, Additive manufacturing, Corrosion, Deep geological disposal canister