Microstructure and Mechanical Properties of Biomedical Ti-Zr-Nb-Ta-Sn High-Entropy Alloys

Ti(50-x)Zr38NbxTa8Sn4 high-entropy alloys with x = 0, 10, and 20 at.% were produced by vacuum arc melting in a high-purity argon atmosphere. The initial microstructures consisted of equiaxial bcc grains sizes 115 ± 30 µm, 250 60 280 70 µm for the Ti30Nb20, Ti40Nb10, Ti50Nb0 alloys, respectively. Ti30Nb20 Ti40Nb10 showed untypical mechanical behavior short strain-hardening stage followed gradual decrease flow stress after reaching yield point. Although these two had some inclination toward macroscopic strain localization, their tensile elongation was similar to that obtained alloy, which more extended uniform deformation. differences associated distinct observed deformation fracture. formation dislocation bands activation cross-slip at microscale, as well appearance kink mesoscale, can result plastic instability. In contrast, lamellar-like microstructure parallel bands, such one ensure stable behavior. developed (Ti30Nb20 Ti40Nb10) have properties make them highly attractive biomedical application due combination very high strengths (1090 930 MPa, respectively), low Young’s moduli (~78 ~69 GPa, reasonable ductility, excellent biocompatibility.