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.

Biocompatible beta-titanium alloys such as Ti-27.5(at.%)Nb are good candidates for implantology and arthroplasty applications as their particular mechanical properties, including low Young's modulus, could significantly reduce the stress-shielding phenomenon usually occurring after surgery. The CLAD® process is a powder blown additive manufacturing process that allows the manufacture of patient specific (i.e. custom) implants. Thus, the use of Ti-27.5(at.%)Nb alloy formed by CLAD® process for biomedical applications as a mean to increase cytocompatibility and mechanical biocompatibility was investigated in this study. The microstructural properties of the CLAD-deposited alloy were studied with optical microscopy and electron back-scattered diffraction (EBSD) analysis. The conservation of the mechanical properties of the Ti-27.5Nb material after the transformation steps (ingot-powder atomisation-CLAD) were verified with tensile tests and appear to remain close to those of reference material. Cytocompatibility of the material and subsequent cell viability tests showed that no cytotoxic elements are released in the medium and that viable cells proliferated well.

The aim of this paper is twofold: firstly, to compare the microstructural and the mechanical properties of Ti-44Nb samples manufactured pre-alloyed powder and differential injection, and secondly, to demonstrate the feasibility of the differential injection method included in the DED-CLAD ® process, to manufacture functionally graded Ti-Nb alloys. Functionally graded materials (FGM) are promising new materials which are perfectly adapted to custom-made parts with various properties for specific applications. In FGMs, titanium and niobium ratios were modified in different steps to create the variation in alloy composition owing to a double-powder feeder. Mechanical analysis and SEM observations show the variation along the deposition depending on the chemical composition. Chemical analysis revealed the homogeneous repartition of the powder mixture as well as the nominal composition of each deposition. Mechanical tests showed a decrease of the microhardness with the increase of Nb content. The elastic modulus was found to be the lowest for Ti-40Nb.

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Purpose – The purpose of this paper consists in the optimization and understanding of the Selective Laser Melting (SLM) manufacturing process of biomaterials, such as T40 and CoCrMo, as scaffolds. Moreover, process optimization is also challenging, with regards to the huge number of parameters and their influence on the finished product. Design/methodology/approach – The paper opted for an exploratory study using Taguchi analysis method to precisely identify the most relevant parameters and justify the energy estimation. Findings – The study showed that SLM fits perfectly with the T40 and CoCrMo part manufacturing. This method allowed to have a complete overview of all the potential applications of SLM for implant manufacturing. Originality/value – With this research approach, the results may be generalized to other material and showed a good theoretical approach.