Role Of Beta-stabilizer Elements In Microstructure And Mechanical Properties Evolution Of PM Modified Ti Surfaces Designed For Biomedical Applications

The aim of this work focuses on the evaluation of modified Ti surfaces produced by powder metallurgy. These new designed materials are processed by deposition and diffusion of a stable aqueous suspension prepared in one case from micro-sized Nb powder (Ti β-stabilizer element); and in another case, from Nb plus the addition of ammonium chloride, NH4Cl, (thermo-reactive diffusion process). Different design parameters such as: diffuser element (Nb or Mo), state of the Ti substrate (green or sintered) and the treatment process (diffusion or thermo-reactive diffusion) lead to all the surface-modified materials, GreenTi-Nb, SintTi-Nb and Ti-NbNH4Cl, GreenTi-Mo, SintTi-Mo and Ti-MoNH4Cl. They present a gradient in composition and microstructure (β – α/β – α phases) resulting in an improvement in some of their mechanical properties: (1) higher micro-hardness in all the modified materials, and (2) lower elastic modulus (more similar to that of the human bone) in those without NH4Cl.