Improvement in Corrosion Resistance of Al-Cu Alloy by Large-area Electron Beam Irradiation

Al-Cu alloy has been widely applied to automobile and aircraft products due to its high strength and low density. However, pitting corrosion easily occurs at intermetallic compounds (IMCs) of Al-Cu alloy. Thus, improvement in corrosion resistance of Al-Cu alloy by refinement of IMCs has been required. On the other hand, large-area EB with 60 mm in diameter can be used for melting the wide area of metal surface uniformly and instantly. Then, surface smoothing of mold steels can be performed efficiently. In addition, re-solidified layer with fine microstructures can be formed on the metal surface after the EB irradiation. It is highly expected that IMCs on Al-Cu alloy surface may be refined in re-solidified layer produced by the EB irradiation. In this study, the possibility for refinement of IMCs on Al-Cu alloy surface by large-area EB irradiation was investigated. Then, improvement in corrosion resistance of Al-Cu alloy surface was proposed.