Effect of volumetric energy density on the microstructure, mechanical, corrosion, and biological behavior of Ti-Cu alloy manufactured by laser powder bed fusion

This study investigates the influence of volumetric energy density ( VED ) on the microstructural evolution, mechanical behavior, corrosion resistance, and biological performance of Ti–10Cu alloys fabricated via laser powder bed fusion (LPBF). Varying VED significantly affects the formation and distribution of Ti 2 Cu intermetallic phases and α′-martensite refinement in the as-built microstructure. Results show that higher VED promotes better copper dissolution, enhanced formation of TiCu intermetallic, and refined α′-Ti laths, resulting in improved hardness. Electrochemical testing in phosphate-buffered saline (PBS) reveals that moderate VED yields optimal corrosion resistance, while excessive TiCu formation at high VED may trigger micro-galvanic corrosion. Antibacterial disk diffusion and MTT assays confirm that Ti–10Cu samples exhibit strong bactericidal activity against E. coli , with A2 and A3 samples showing significant antibacterial zones. Importantly, all samples maintain acceptable cytocompatibility, with A2 offering the best balance between antimicrobial performance and cell viability. This work establishes a clear process–structure–property–performance relationship for LPBF Ti–10Cu and provides guidance for tuning VED to optimize functional outcomes in biomedical applications.