Role of beta-stabilizing elements on the microstructure and mechanical properties evolution of modified PM Ti surfaces designed for biomedical applications Articles uri icon

publication date

  • January 2018

start page

  • 90

end page

  • 99

issue

  • 2

volume

  • 61

international standard serial number (ISSN)

  • 0032-5899

electronic international standard serial number (EISSN)

  • 1743-2901

abstract

  • This work focuses on the evaluation of modified surfaces on Ti produced by powder metallurgy. These newly designed surface modifications are achieved by deposition and diffusion of a stable aqueous suspension prepared in one case from micro-sized Nb powder (Ti beta-stabilizer element) and in another case from Nb plus the addition of ammonium chloride, NH4Cl, (thermo-reactive diffusion process). Different design parameters such as diffusion 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-Nb-NH4Cl, GreenTi-Mo, SintTi-Mo and Ti-Mo-NH4Cl. The modified Ti surfaces present a gradient in composition and microstructure (beta / alpha+beta / alpha 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.

keywords

  • titanium; surface-modification; powder technology; microstructural-gradient; elastic modulus; hardness