Mechanical and biological performance of TNZT-xSi-yMn composites for bio-implant applications

Ti-35Nb-7Zr-4Ta (TNZT) composites containing varying concentrations of Si (0.5-1 wt%) and Mn (1-2 wt%) were fabricated using conventional powder metallurgy to evaluate their mechanical, surface, and biological performance for biomedical implant applications. The microstructural evaluation revealed that the addition of Si and Mn refined the grain structure and promoted the formation of silicide phases, as confirmed by EDS and x-ray diffraction. The incorporation of Si and Mn significantly enhanced the mechanical properties, achieving a yield strength of 801 ± 27 MPa and an ultimate compressive strength of 914 ± 32 MPa while maintaining a relatively low elastic modulus compared to Ti-6Al-4 V. The wettability and surface free energy measurements revealed that the addition of Si and Mn increased the contact angle and reduced the surface free energy. The atomic force microscope results indicated a reduction in the surface roughness owing to grain refinement. The Ti-35Nb-7Zr-4Ta-0.75Si-1Mn (M4) composite exhibited significantly enhanced antibacterial activity againstS. aureusand demonstrated excellent cell viability with MC3T3-E1 osteoblast cells. Statistical analysis (p> 0.05) indicated no significant difference in cell viability compared to the TNZT and negative control groups, indicating good cytocompatibility. These results suggest that the M4 composite has strong potential for bio- implant applications.