Characterization of a Ti-Nb-Zr-Ta alloy processed by selective laser melting

Full text: Selective Laser Melting (SLM) is an additive manufacturing process, by which a laser beam selectively melts a powder bed and by repeating this process layer by layer accordingly with a 3D CAD model, prostheses with complex shape and customized density can be produced [1]. Biocompatible beta-TiNb alloys have been specially considered as promising to be used in prostheses because their low Young's modulus and their excellent biocompatibility [2]. The main objective of this study was to investigate the microstructure and mechanical properties of a beta Ti-35Nb-7Zr-5Ta (TNZT) alloy processed by SLM. Rods were produced in a SLM Realizer 50 with a laser power of 129W, scanning speed of 0,57 m/s and layer thickness of 40 μm, in argon atmosphere. The samples were characterized by X-ray diffraction, optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, electron backscatter diffraction and compression tests. The samples presented columnar-dendritic and equiaxial grains of the beta- Ti phase, preferably oriented in the building direction. Relative density higher than 99.5% and very high ductibility under compression. References: [1] Tahara, M. et al. Materials Science and Engineering A, 527 (2010). [2] Elias, C. N. et al. The Journal of The Minerals, Metals & Materials Society, p. 4 (2008). (author)