Role of Silicon in the Microstructural Development and Properties of Ti-15Nb-xSi Alloys for Biomedical Applications

Abstract Ti-Nb alloys are attractive for biomedical implants and the addition of Si can lead to an improved set of properties. This study investigates the effect on the microstructures and properties of solution-treated Ti-15Nb-xSi alloys followed by furnace cooling (FC), and water quenching (WQ). Based on the results, Si acts as a β-stabilizing element by increasing the β volume fraction from 13%–36% in FC samples to a range from 0%–0.55% Si. The elastic modulus decreased under both conditions and reached approximately 63 GPa in WQ samples with 0.35% Si due to an increased α” unit cell volume. On the other hand, hardness increased with increased Si content under FC and WQ conditions to a maximum of 313 HV in the WQ sample containing 0.55% Si.