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Materials Science in Additive Manufacturing Additive manufacturing of 316L-Cu alloys

A1 B1 C1

A2 B2 C2

D E

Figure 6. SEM imaging and agar plate quantification of P. aeruginosa activity. (A1 and A2) 316L control surface with increasing CFU count over time.
(B1 and B2) SS-3Cu and (C1 and C2) SS-5Cu show a significant reduction in bacteria with respect to the control composition. (D) CFU quantification of
SEM images with n = 3 per condition. Statistically significant values are marked as *P < 0.05, **P < 0.01, ***P < 0.001. (E) Normalized bacterial viability
for each time point
Abbreviations: CFU: Colony-forming units; SEM: Scanning electron microscopy

this protection is temporary. Similarly, antibacterial coatings inhibited in SS-3Cu and SS-5Cu samples, emphasizing the
can be applied to implants, but their efficacy may diminish potential of these alloys for biomedical applications. These
as the coatings degrade. In contrast, Cu addition provides an findings align with previous studies on 316L-Cu alloys
inherent antibacterial effect that may last for the entire lifespan produced using AM and conventional methods. 7,10,29
of an implant, preventing bacterial colonization and biofilm
formation for extended periods after implantation. However, 5. Conclusions
antibacterial implants alone may not address infection risks on This study investigated the microstructural, mechanical,
surfaces not in direct contact with the device, such as adjacent and antibacterial properties of 316L SS with 3 wt.% and
tissue near the surgical site. Therefore, 316L-Cu alloys could 5 wt.% Cu produced through powder-based laser-directed
be used in conjunction with antibiotics or coatings to provide energy deposition. The following conclusions can be drawn
both short- and long-term antibacterial protection. from this study:
This study measured antibacterial performance against (a) The incorporation of Cu resulted in no significant
S. aureus (Figure 5) and P. aeruginosa (Figure 6). The change in the microstructure and appeared to form a
results demonstrated that both Cu compositions exhibited homogenous distribution of Cu within the matrix, as
significant antibacterial efficacy compared to 316L. SS-5Cu confirmed by SEM, EDS, and XRD.
showed greater effectiveness than SS-3Cu due to its higher Cu (b) Compressive strength and hardness values remained
content, consistent with prior studies that report increased comparable to 316L despite these elemental modifications.
antibacterial efficacy with progressive Cu addition. 7-9,12 The A slight reduction in yield strength was observed for
growth of both S. aureus and P. aeruginosa was significantly SS-5Cu (317 ± 1 MPa) compared to 316L (334 ± 9 MPa)

Volume 4 Issue 1 (2025) 9 doi: 10.36922/msam.7357