Relationship between microstructure, phase transformation, and mechanical behavior in Ti–40Ta alloys for biomedical applications

Abstract

Titanium and Ti alloys are important materials for scientific and technological applications, especially as biomaterials, due to their excellent corrosion resistance, biocompatibility, and mechanical properties. In this work, the influence of tantalum on the microstructure and mechanical properties of Ti–40Ta alloys were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM), differential scanning calorimetry (DSC), and mechanical spectroscopy (MS) techniques. XRD and SEM analyses showed that commercially pure (CP) Ti consists of a single α-phase (hcp) with an equiaxed morphology, while Ti–40Ta alloy consists of α'' (orthorhombic) and β (bcc) phases. The anelastic relaxation spectra of Ti–40Ta alloy presented characteristics combining CP Ti and pure Ta anelastic responses, where the complex anelastic relaxation peaks observed around 575 and 680 K could be resolved into matrix-interstitial and substitutional-interstitial components, corresponding to Ta–O, Ti–O, and Ta–N single interactions. The combination of thermal cycles and applied stress during the mechanical spectroscopy characterization of Ti–40Ta alloy promotes the α'' → β phase transition until β phase stabilization. From flexural vibration measurements, the elastic modulus values at room temperature were: (102 ± 9) GPa for CP Ti and (71 ± 5) GPa for the Ti–40Ta alloy. These results provide a valuable contribution to a better understanding of the structure and mechanical properties of the Ti–40Ta alloy, thus allowing the optimization of its properties through thermal treatments, aiming at its potential application as a biomaterial for structural orthopedic applications.

Keywords

• Ti–40Ta alloy
• Biomaterials
• Biomedical alloys
• Mechanical spectroscopy
• Internal friction
• Elastic modulus