Abstract
The development of antibacterial coatings is very important for reducing pathogenic microorganisms on frequently touched surfaces. This study explores the formation of copper-based antibacterial coatings on 304 stainless steel using laser powder bed fusion (L-PBF) and integrates molecular dynamics (MD) simulations to analyze the melting and coalescence processes at the nanoscale. Experimental results showed heterogeneous copper distribution in the melting pool, with Cu-rich regions reaching up to 69 at. %. SEM-EDS analysis confirmed localized phase separation due to rapid solidification and Marangoni convection. MD simulations of Cu-304SS nanoparticles demonstrated significant copper surface segregation at 1600 K, validating experimental observations. The antibacterial efficacy of the coatings was assessed against Escherichia coli and Acinetobacter baumannii. Results showed complete bacterial inactivation within 1 h of exposure. These findings provide insights into optimizing L-PBF parameters for creating durable and efficient self-disinfecting surfaces.