Ti-Nb alloys are excellent candidates for biomedical applications such as implantology and joint replacement because of their very low elastic modulus, their excellent biocompatibility and their high strength. A low elastic modulus, close to that of the cortical bone minimizes the stress shielding effect that appears subsequent to the insertion of an implant. The objective of this study is to investigate the microstructural and mechanical properties of a Ti-Nb alloy elaborated by selective laser melting on powder bed of a mixture of Ti and Nb elemental powders (26 at.%). The influence of operating parameters on porosity of manufactured samples and on efficacy of dissolving Nb particles in Ti was studied. The results obtained by optical microscopy, SEM analysis and X-ray microtomography show that the laser energy has a significant effect on the compactness and homogeneity of the manufactured parts. Homogeneous and compact samples were obtained for high energy levels. Microstructure of these samples has been further characterized. Their mechanical properties were assessed by ultrasonic measures and the Young's modulus found is close to that of classically elaborated Ti-26 Nbingot.

Ti and its alloys have a variety of applications in aerospace industry and medical implants. The formation of hydride has been used in biomedical areas and can significantly influence the mechanical performance of materials. In this work, we investigate the orientation dependence of hydride precipitation in commercially pure titanium via interrupted in-situ electron backscatter diffraction (EBSD) measurements. The results reveal that hydrides during hydrogen charging at room t emperature exhibit two types of orientation relationships with α-titanium, i.e., {0001 α //{11 ̅ 1 <12 ̅ 10> α //<110> with interface plane {101 ̅ 3 α //{11 ̅ 0 (B-type), and {0001 α //{001 <12 ̅ 10> α //<110> with interface plane {101 ̅ 0 α //{11 ̅ 0 (P-type). Significant orientation dependence of hydride precipitation is observed, especially when *101 ̅ 3+, *101 ̅ 0+, *0001+ or *112 ̅ 0+ planes of the parent grains are parallel to the diffusion surface. The displacement gradient tensor based accommodation shows that the orientation 2 dependence is attributed to the strain relaxation of hydride transition. Three types of hydride platelets are characterized: parallel hydride platelets (Type I), crossed hydride platelets (Type II) and clustered hydride platelets (Type III). The multiple morphologies of hydride platelets resulting from the hydride variant selection and interaction are dependent on the crystal orientation of the matrix.