Construction of wear-resistant and anti-corrosion composite coatings on uranium surface by laser surface nitriding and texture coupled with solid lubrication

Abstract

Uranium metal has attracted considerable attention due to its unique physicochemical properties and has generated widespread interest in the field of nuclear power. However, the uranium surface is prone to wear and corrosion, leading to performance degradation. In addition, the high chemical reactivity and strong radioactivity of metallic uranium pose challenges to the long-term stability of traditional protective coatings on its surface. In recent years, significant research progress has been made in improving the wear resistance and corrosion resistance of uranium substrates through surface alloying or laser shock processing techniques. Nevertheless, the problem of wear and corrosion of the modified layer on the uranium surface under a prolonged harsh environment remains unresolved. This study proposes a ternary synergistic strategy of “two-dimensional solid lubrication, micro-texture friction reduction, and nitrided layer hardening passivation” to prepare a modified layer on the uranium surface with robust radiation resistance and reliable protection. The composite modified layer not only effectively improves the wear-resisting and anti-corrosion of the uranium surface but also resists robust radiation. The research shows that the modified coating prepared retains its silver-white metallic sheen following 48 h of accelerated corrosion testing in pure water vapor at 338.15 K. Additionally, friction coefficient measurements from wear experiments reveal that the modified layer exhibits a coefficient of friction below 0.05. The ternary synergistic strategy provides crucial theoretical guidance and a technical roadmap for enhancing the wear and corrosion resistance of uranium materials in the atmospheric environment.