A novel low copper content antibacterial high-entropy alloy: Role of synergistic effect of multiple elements

Antibacterial high-entropy alloy (AHEA) is a novel metallic material known for its excellent antibacterial properties due to its significant copper (Cu) content. This study presents a low copper content AHEA (LCC-AHEA) to improve plasticity and corrosion resistance by eliminating Cu-rich phases. The LCC-AHEA shows a compressive yield strength of ∼751 MPa and tensile yield strength of ∼525 MPa, resulting from the refined microstructures. Furthermore, the LCC-AHEA exhibits a 100% antibacterial rate against Escherichia coli ( E. coli ) within three days for the poor wettability and the synergistic effect of multiple ions. The poor wettability hinders the adhesion of bacteria and biofilms. Additionally, the release of Al, Co, Ni, and Cu ions due to corrosion results in morphological changes in E. coli and has a synergistic effect on suppressing bacterial cell division by inhibiting both DNA replication and mitosis. Moreover, the passive zone of LCC-AHEA is four times greater than that of stainless steel, preventing the dissolution of harmful ions following the inactivation of E. coli . These excellent properties of LCC-AHEA demonstrate its great potential for medical applications.