Recently, the research group led by Professor Xu Dake from Professor Wang Fuhui's team at the School of Materials Science and Engineering has achieved innovative results in the design of high-entropy alloys that combine anti-microbial contamination and corrosion resistance. The related research is titled "Al/Cu Enhancement in Marine Anti-Biofouling and Anti-Biocorrosion Performance of High-Entropy Alloys" and published on Advanced Functional Materials—an internationally leading journal in materials science. Yang Linlin, a doctoral student from the School of Materials Science and Engineering, and Zhou Enze, a specially-appointed researcher, are the co-first authors. Professor Xu Dake, specially-appointed researchers Zhou Enze and Cui Miaomiao are the co-corresponding authors. NEU is the first completing institution and the only corresponding institution.
Marine engineering materials have long been plagued by the dual challenges of microbial corrosion and biofouling. These problems caused by biofilms seriously threaten the service safety of the materials. Most of the existing antibacterial alloys rely on antibacterial elements such as copper and silver, but often at the expense of the mechanical properties and corrosion resistance of the materials. In response to this technical bottleneck, the research group innovatively designed a series of AlxCoCrCuFeNi high-entropy alloy systems with adjustable Al content, achieving breakthroughs in material performance through precise regulation of elemental composition.
Research has found that when the Al content is 0.3 (Al0.3CoCrCuFeNi), the alloy demonstrates outstanding comprehensive performance. Its yield strength (360 MPa) is more than twice that of 316L stainless steel (170 MPa), and the inhibition rate of Pseudomonas aeruginosa biofilm reaches 94.1%. The resistance to microbial corrosion (polarization resistance value) is nearly 20 times higher than that of aluminum-free high-entropy alloys. The synergistic effect of Al and Cu forms a unique microstructure: Cu is enriched in the grain boundary region and continuously releases antibacterial ions. By destroying the cell membrane and inducing the aggregation of reactive oxygen species within the cell, antibacterial ions effectively inhibit the adhesion and growth of bacteria and algae. Meanwhile, the Al element inhibits the corrosion of microcouples by regulating the potential difference of the Cu phase and prevents excessive dissolution of the Cu phase. The two elements work together to ensure long-term stable anti-fouling performance. Meanwhile, the introduction of Al promotes the uniform distribution of Al2O3 and Cr2O3 in the surface passivation film, significantly enhancing the corrosion resistance of the material. This research not only reveals the synergistic mechanism of Al/Cu, but also provides a new paradigm for the design of marine protective materials. Through the multi-principal element collaborative design of high-entropy alloys, the optimal balance of mechanical properties, antibacterial properties and corrosion resistance can be achieved simultaneously. The research results are of great guiding significance for the development of new engineering materials suitable for harsh marine environments.
This research has been supported by the National Science Fund for Distinguished Young Scholars, the China Association for Science and Technology's Youth Talent Support Program, the National Natural Science Foundation of China, and the China Postdoctoral Science Foundation, among others.
