Structural analysis of a Nb-based alloy for biomedical application

The purpose of research in the biomaterials field is to produce new materials with physical and chemical properties close to the tissue to be replaced with minimal toxic response to the foreign body. Among the various metallic materials, titanium and its alloys have this great combination of properties. The most promising alloys are those with niobium, molybdenum, tantalum, and zirconium as alloying elements added to titanium. Thus, this kind of alloys integrate a new class of alloys without aluminum and vanadium (which cause cytotoxicity) and have a low modulus of elasticity (below 100 GPa). The objective of this work is to analyze the structure and microstructure of a niobium-based alloy, Ti-50wt%Nb. This alloy was produced in an arc-melting furnace with an inert atmosphere of argon gas. After melting, the samples were characterized by density, X-ray diffraction, scanning electron microscopy, and hardness. The X-ray diffraction data shows the peaks corresponding to the beta phase (with body-centered cubic crystalline structure), corroborated by scanning electron microscopy images. The value of the lattice parameter of the body-centered cubic crystalline structure was 3.2868 Å.

Anelastic relaxation due to hydrogen in Ti-35Nb-7Zr-5Ta alloy

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Titanium and its alloys are frequently used in the production of prostheses and dental implants due to their properties, such as high corrosion resistance, low elasticity modulus, and high mechanical strength/density relation. Among the Ti-based alloys, Ti-35Nb-7Zr-5Ta (TNZT) is one that presents the smallest elasticity modulus (around 45 GPa), making it an excellent alternative to be used as a biomaterial. In this paper, mechanical spectroscopy measurements were made of TNZT alloys containing several quantities of hydrogen in solid solution. Mechanical spectroscopy measurements were made by using a torsion pendulum, operating at an oscillation frequency in the interval 2-20 Hz, temperature in the range 100-300K, heating rate of about 1 K/min, and vacuum lower than 10(-5) Torr. A relaxation structure and a reduction in the elasticity modulus were observed for the heat-treated and doped samples. The observed peak was associated with the interaction of hydrogen trapped by oxygen atoms around the titanium atom of the metallic matrix. (C) 2011 Elsevier B.V. All rights reserved.528933263329Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

Cytotoxicity study of some Ti alloys used as biomaterial

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)An implanted material is considered biocompatible, if adverse and uncontrollable reactions don't exist in the biological system. in this sense, biocompatibility tests made in the constituent materials are very important so that the implants have Success. The in vitro cytotoxicity tests represent the initial phase of the process, and Could be considered as a pre-selection of those materials. in vitro techniques using cell culture have become widely used in the evaluation of biomaterial cytotoxicity, which has contributed to their standardization and the substitution of in vivo tests. This paper shows a study of the in vitro cytotoxicity of two Ti based alloys, Ti-13Nb-13Zr and Ti-35Nb-7Zr-5Ta, in the as-received condition and after heat treated. The results show that the alloys presented no cytotoxic effects in the studied conditions. (C) 2008 Elsevier B.V. All rights reserved.29413651369Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP