Fatigue Behaviour of the TiAlV Alloy Used in Biomedical Applications: Case Study

The present work focuses on the fatigue behaviour of the additively manufactured Ti6Al4V-ELI alloy, which is mainly used for biomedical applications such as implants and prosthetics. It was found that the studied material is characterised by an almost fully dense (relative density higher than 99.97%) microstructure, which consists of needle-like α-Ti lamellae with β-Ti phase on their boundaries. Fatigue tests showed that the lifespan of the Ti6Al4V-ELI alloy produced by laser powder bed fusion within the stress amplitude of 300–400 MPa lies in the range of 106–107 cycles. Scanning electron microscope fractographic images showed that the surface of the studied material plays the most important role in determining the material’s lifetime. The findings of this study contribute to a deeper understanding of the structure–property relationships in terms of extremely damaging fully reversible (tension-compression) fatigue measurements in additively manufactured Ti6Al4V-ELI and support the development of more reliable biomedical components, especially hip joint prostheses.