Development of TiB and TiN Reinforced Beta Titanium Alloys Produced by Powder Metallurgy Route

摘要

Low tribocorrosion resistance and high Young's modulus are frequent problems presented in the current biomedical Ti alloys. Ti-Nb β alloys allow decrease the elastic modulus compared to other biphasic (α+β) Ti alloys maintaining good mechanical properties. On the other hand, the addition of ceramic reinforcements such as TiB_2 and TiN diminishes the release of metallic ions and wear debris which could generate local and systemic effects. In this study, three materials of the Ti-Nb and Ti-Nb-Fe system were reinforced with 5 vol.% of TiB_2 and TiN. Samples were produced by conventional powder metallurgy route starting from TiH_2 powder. TiH_2 creates a protective atmosphere, due to the hydrogen released during the process of TiH_2 decomposition, and in addition, promotes higher densification compared to compact Ti samples sintered at the same conditions. The interaction between TiB_2 and TiN reinforcements and matrix was studied. Composite samples were characterized through XRD, SEM, hardness and wear tests.