Carbon dot/nickel nanocomposite coating for wear and corrosion control of Mg alloy: Experimental and theoretical studies

• Published in: Applied surface science 2024-06, Vol.659, p.159845, Article 159845
• Main Authors: Zhou, Shengguo, Liu, Zhijing, Lu, Zhibin, Ma, Liqiu
• Format: Article
• Language: English
• Subjects: Carbon dots; Corrosion; Nickel coating; Wear
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2024.159845

[Display omitted] •Synthesized CDs endow a compacted carbon dot/nickel coating with superior mechanical properties.•Efficient Self-lubricating CDs contribute to excellent tribology for carbon dot/nickel coating.•High penetrating energy barrier of Cl makes CDs to be an excellent inhibitor.•Carbon dot/nickel coating provides an effective controlling wear and corrosion to Mg alloy. Due to their self-lubrication and corrosion inhibition properties, carbon dots (CDs) were utilized to endow a nickel coating on a magnesium alloy substrate with superior tribology and anti-corrosion properties. The surface and cross-sectional morphologies confirm that these novel carbon dots remarkably improve the compactness of the nickel coating, leading to much higher hardness and adhesion strength. The carbon dot/nickel coating prepared with 0.5 g/L CDs has a lower wear rate and friction coefficient than the other coatings, demonstrating its excellent self-lubricating performance. Moreover, as demonstrated by electrochemical tests and the formation of corrosion products, this coating exhibits significantly enhanced anti-corrosion performance, with the lowest corrosion current and largest impedance modulus among the prepared coatings. Theoretical calculations confirm that the CDs provide a high energy barrier for the penetrating diffusion of Cl. Thus, the CDs effectively prevent the active penetration of corrosive substances. As a result, the as-prepared carbon dot/nickel nanocomposite coatings can efficiently control the wear and corrosion failures of Mg alloy under some harsh conditions.