Influence of Porosity on the Elastic Modulus of Ti-Zr-Ta-Nb Foams with a Low Nb Content

Abstract

The development of titanium foams with a low elastic modulus has increased their scientific and technological relevance due to the evident need to avoid stress shielding problems. In this work, we studied the synthesis and characterization of Ti-13Zr-13Ta-3Nb (wt.%) alloy foams which present high potential for biomedical applications. A Ti-Nb-Ta-Zr mixture was produced by mechanical alloying using a planetary mill. Ti alloy foams were obtained using NaCl as a space-holder (40, 50, and 60 v/v %) that was mixed with the metallic powders and compacted under 420 MPa stress. NaCl particles were removed from the green compacts by submerging samples in distilled water at 60 °C. The green compacts were sintered at 1300 °C for 3 h in Ar atmosphere. Powders and foams were characterized by SEM and optical microscopy. The results showed that Ti-based foams with a tailored heterogeneous pore distribution can be obtained using the space holder method. The elastic modulus (E) of foams was estimated and measured between 5 and 25 GPa using theoretical and finite element analysis (FEA) models which are close to the E values measured experimentally. The results showed that foams with 50% and 60% porosity are potential bone replacement materials because their E value is closer to the E value of human bone.

Biomedical Ti-Nb-Zr Foams Prepared by Means of Thermal Dealloying Process and Electrochemical Modification

“…The smaller pore morphology was dramatically changed in terms of pore size and shape (compare Figure 3 f and Figure 6 d). The surface was more developed compared to that of foam before etching and definitely more developed than those of other authors’ results [ 10 , 19 , 23 , 37 ]. The pore size was in the rage of 0.5–5 µm and definitely of round shape.…”

“…Aguilar et.al. [ 19 ] prepared Ti13Zr13Ta3Nb foams using NaCl as a space-holder. Their material had pore size distribution from 20 to 600 µm.…”

“…Ti-Nb-Zr alloys are still extensively researched and are the most attractive alloys for biomedical application due to their biological and mechanical properties, with Young’s moduli and yield strength ranging from 50 to 85 GPa and from 350 to over 900 MPa, respectively. Some of the alloys show a shape memory effect and superelasticity at room temperature [ 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 ].…”

“…In this work, we decided to investigate Ti20Nb5Zr foams prepared by mechanical alloying (MA) with addition of 30% of Mg, followed by thermal dealloying. The Ti-Nb-Zr alloys are well-described in the literature and show good properties from a biomaterials point of view [ 18 , 19 , 20 , 21 , 22 , 23 ]. One of the goals of this study was to investigate the preparation of such alloys by MA in the presence of Mg.…”

A state-of-the-art review of the fabrication and characteristics of titanium and its alloys for biomedical applications

“…Different β-type titanium alloys compounded with elements such as oxygen (O), silicon (Si), and zirconium (Zr) to produce Ti − 13Zr − 13Ta (a near β-type titanium alloy), Ti − 12Mo − 6Zr − 2Fe, T − 15Mo, and Ti − 15Mo − 2.8Nb − 0.2Si − 0.28O, were developed in the USA. On the Japanese front, β-type titanium alloys such as Ti − 15Mo − 5Zr − 3Al, Ti − 15Mo − 5Zr, and Ti − 15Zr − 4Nb − 4Ta were formulated [ 24 – 30 ].…”