Investigation of In Vitro Corrosion and Wear Properties of Biomedical Coatings Applied to Ti6Al4V Alloy Manufactured by Selective Laser Melting

This study focuses on enhancing the biomedical performance of PBF-LB Ti6Al4V, produced using Selective Laser Melting (SLM), an advanced manufacturing technology widely used for patient-specific medical devices and implants. Hydroxyapatite (HA), titanium (Ti), and bilayer Ti/HA coatings were applied, using the powder flame spray coating technique. A comprehensive analysis was conducted to examine the microstructural, chemical, and mechanical properties of the coatings. Surface analysis was performed using a scanning electron microscope (SEM), chemical composition was determined by energy-dispersive spectroscopy (EDS), crystal structure was analyzed via X-ray diffraction (XRD), and surface roughness was evaluated through topographic analyses. Additionally, in vitro wear and corrosion resistance tests, crucial for biomedical applications, were conducted. In wear tests, HA coatings exhibited the lowest wear resistance with the highest wear rate (73.83 × 10−3 mm3/N·m), while Ti coatings showed the highest wear resistance (6.32 × 10−3 mm3/N·m), and Ti/HA coatings demonstrated an intermediate performance (34.22 × 10−3 mm3/N·m). Corrosion tests revealed that bilayer Ti/HA coatings provided the best protection (0.00009 mm/year), followed by Ti coatings (0.0002 mm/year) and HA coatings (0.003 mm/year). The results indicate that Ti/HA coatings offer the most suitable biomedical performance.