Si-modified beta-Ti–25Mo biomaterials with reduced elastic modulus, enhanced corrosion resistance, and cytocompatibility
One of the key challenges for β-Ti alloys in biomedical applications is achieving a balance among low elastic modulus, high corrosion resistance, and cytocompatibility. In this study, Ti25MoxSi alloys (x = 0–2 wt.%) were designed to ensure a metastable β-phase. The alloys were fabricated using vacuum arc melting. Their microstructures and surfaces were evaluated by optical microscopy and XRD to assess the constituting phases. The elastic modulus and hardness of the alloys were evaluated using nanoindentation. The corrosion behavior in aerated Ringer’s solution using Electrochemical analysis. SEM, MTT assay, and live/dead cell assay were used to examine the in vitro biological responses of all alloys. Optical microscopy shows equiaxed β-Ti grains in all alloys, with ultrafine silicide precipitates at grain boundaries in 1.5 and 2 wt.% Si content. XRD analysis reveals stable β-phase for all alloys. The nanoindentation studies show a reduced elastic modulus of 80–85 GPa. A significant enhancement in hardness was observed with typical values around 4 GPa. Preliminary electrochemical studies show improved corrosion resistance, suggesting the formation of a passive film upon adding Silicon. In vitro studies using MC3T3-E1 cells confirm cytocompatibility across all compositions. The study highlights the potential of Ti–Mo–Si alloys for load-bearing biomedical implants.