Processing and Characterization of Ti-6Al-4V Samples Manufactured by Selective Laser Melting

Abstract:

Titanium and its alloys are well known as one of the best in-vitro and in-vivo bone replacement metallic biomaterial due to its excellent balance between biomechanical and biofunctional properties. The selective laser melting (SLM) method has a lower cost and shorter manufacturing time than the conventional routes used in the fabrication of titanium alloys. In this work, Ti6Al4V sheets were manufactured by SLM (LM samples) and subsequently annealed for stress relief at 750 oC for 10 min (LM-A samples). SEM, XRD and contact profilometry measurements were carried out to characterize the elemental composition, phases and surface morphology of different samples. A micro-tribo-mechanical evaluation was also performed by micro-indentation and scratch tests. The resulting surface was rough (Ra = 9.1 ± 0.5 μm) for all samples, showing protuberances with spherical morphology. For annealed samples, an oxide layer composed of rutile and Al₂O₃ was observed that increased the micro-hardness of the surface in LM-A sheets. However, after removing this oxide layer, the micro-hardness of the LM-A sheets was reduced when compared to LM samples as a result of the stress relief. A direct relationship between Vickers micro-hardness and scratch resistance was always observed. Therefore, LM-A sheets showed higher scratch resistance at low loads (oxidized surface effect) than LM samples, but lower resistance at high loads (bulk effect).

• Periodical: Key Engineering Materials (Volume 704)
• Pages: 260-268
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.704.260
• Online since: August 2016
• Authors: Perla Sarria, Yadir Torres*, Francisco José Gotor, Eliel Gutiérrez, Melchor Rodríguez, Ramón González, Laura Hernández, Eduardo Peón, Hugo Guerra, Jesús E. González
• Keywords: Biomaterials, Selective Laser Melting, Surface Modification, Titanium Alloy, Tribo-Mechanical Behavior

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