Influence of Oxygen Content and Microstructure on the Mechanical Properties and Biocompatibility of Ti-15 wt%Mo Alloy Used for Biomedical Applications

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Síntese de nanocatalisador cerâmico a base de SnO2 pelo método hidrotermal assistido por micro-ondas aplicado a reação de transesterificação do óleo de babaçu

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Efeito de tratamentos térmicos nas propriedades mecânicas, eletroquímicas e citotoxidade de ligas do sistema Ti-15Mo-XNb

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Determinação da temperatura de referência T0 da curva mestre na região de transição dúctil-frágil de aços ARBL

Materiais estruturais utilizados no projeto de equipamentos e instalações industriais podem apresentar mudança de seu comportamento à fratura quando se varia a temperatura. Este tipo de comportamento caracteriza-se pela existência de uma curva de transição, onde 3 regiões ficam bem definidas: os patamares inferior e superior e a região de transição. Na região de transição, os resultados experimentais apresentam alto espalhamento e são bastante dependentes da geometria ensaiada. Para solucionar este problema, foi desenvolvido um modelo analítico experimental, que resultou na edição da norma ASTM E1921-97. O trabalho inclui um estudo da influência de diversas rotas de tratamentos térmicos aplicadas em um aço 4130 utilizado pela indústria aeronáutica, um aço de qualidade API utilizado pela indústria petrolífera e um aço da classe A516 atualmente utilizado pela indústria nacional de vasos de pressão, na microestrutura, propriedades mecânicas de tração e tenacidade à fratura. Os resultados mostraram que o aço 4130 A450, apresentou a melhor correlação entre resistência e tenacidade entre as microestruturas pesquisadas. Este comportamento deve estar associado a rota de tratamento térmico aplicada a esta condição. O tratamento de austêmpera possibilita a formação de bainita que, tradicionalmente é conhecida por apresentar elevados valores de tenacidade. O método proposto pela ASTM pode ser considerado viável para as diversas microestruturas pesquisadas ampliando a aplicação da metodologia que recomenda o ensaio apenas para aços ferríticos. No entanto, a metodologia da Curva Mestra em materiais tratados termicamente deve ser conduzida de forma a se estabelecer parâmetros que considerem as modificações microestruturais sofridas pelo material.

Translucent tin dioxide ceramics obtained by natural sintering

Dense SnO2-based ceramics (relative density >95%) have been obtained by natural sintering at a moderate temperature (less than or equal to 1300 degrees C) with the help of a small amount of manganese, Further thermal treatments above 1500 degrees C result in grain growth and transport of manganese toward the sample surface. If the ceramic is embedded inside alumina powder, the diffusion of Mn out of the sample and into alumina during such heat treatments leads to a manganese-free body (<40 ppm) which is translucent. The transmission in the visible region depends on sample thickness; 61% was achieved for a 0.05 mm thick sample.

Desenvolvimento de tratamentos térmicos visando ganhos magnéticos em aços com ultra baixa concentração de carbono

The relationship between the microstructure and the magnetic properties of soft magnetic materials, have been studied by different researchers who seek to employ electrical systems, increasing their life span and reduce their energy consumption. Following this same line the Brazilian Synchrotron Light Laboratory developed a new synchrotron light source, the Sirius, where magnetic materials with high magnetic permeability values are being studied for use in accelerator dipoles. The low carbon steel is a ferromagnetic material that has a great relationship between cost and magnetic permeability. Aiming to raise the values of permeability of the material, heat treatments were done and evaluated the magnetic properties, microstructure and mechanical properties to correlate them. It was noted that the thermal annealing were the most effective, and the annealing performed with a small time threshold, which only phenomenon observed was the primary recrystallisation, was the most elevated values of magnetic permeability of the material, due to the average grain size ideal achieved. The heat treatments do not guide the magnetic domains of the material and not influence the mechanical properties of the material due to lack of carbon in the microstructure. The annealing treatments were shown to be an alternative to raising the values of the magnetic permeability of the material and facilitate the implementation of ultra low carbon steel in the dipoles of Sirius

Preparação e caracterização de vidros contendo nanopartículas de Ag

This work consists of preparation and characterization of glasses containing transition noble metals and the study of optical properties of such materials. The glasses were prepared by quenching of the glass melt followed by heat treatment and polishing of the monoliths. The structural characterization of glasses was made using differential thermal analysis, X-ray, Raman and infrared spectroscopies, while the optical properties were studied by UV-Vis and M-Lines spectroscopies. Preliminary results have shown that the color of the glasses is dependent on both concentration of silver and the melting temperature of the melt. Controlled heat treatments have been used to induce the crystallization of Ag nanoparticles within the glass. The study of crystallization was accompanied by electron microscopy and UV-Vis spectroscopy. Data from electron diffraction, as well as chemical analysis, EDX, were obtained using a transmission electron microscope. EDX data have shown that the atomic percentage of Ag is higher on the nanoparticle. X-ray diffraction was used in order to characterize the composition of the crystals and cubic AgCl was identified as the main crystallized nanophase obtained after annealing

Caracterização da liga do sistema binário Ti-15Mo para aplicações biomedicas

As they have excellent mechanical properties, corrosion resistance and biocompatibility, much research has been conducted with respect to biomedical applications of titanium alloys. This work aims to study the experimental system binary alloy Ti-15Mo, in the raw state of fusion and heat treatment after homogenization, solubilization and calcination (simulating conditions employed for nanotube growth) targeting biomedical applications. Samples were obtained by casting the components in an electric arc furnace with inert atmosphere of argon. After obtaining the alloy, it was heat treated at three different heat treatments, namely homogenizing, calcining and simulation solubilization. The phases present were analyzed by X-ray diffraction, optical microscopy and microhardness testing

Aplicação e viabilidade de micro-organisos potencialmente probióticos em embutido cárneo fermentado

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Análise da reversão do fundo de latas de alumínio para bebidas - Buckle

This work approaches the main methods of plastic deformation of metals, with a focus on the deep drawing process. The mechanical properties were evaluated with the tension tests. It is presented the aluminum alloys designation, followed by applying heat treatments and the designation of tempers. The manufacture of aluminum beverage cans is described step by step, in general terms. The main objective is to analyze how different cans background geometries have great influence on the dome reversal. To be able to achieve the goal it was necessary to use cans of different manufacturers, which were used in buckle tests to obtain the reversal pressures, tensile tests and geometric analysis. Finally empirical equations were obtained correlating these variables, and it was observed that the conformation of reforming change significantly it's behavior

Efeitos do tratamento térmico na obtenção da fase 2223 em amostras de BSCCO com e sem substituição

Pós-graduação em Ciência dos Materiais - FEIS

Influência da adição do nióbio no comportamento mecânico e microestrutural do aço SAE 6150

Pós-graduação em Engenharia Mecânica - FEG

Influência do tratamento térmico de homogeneização na microestrutura de um aço utilizado na fabricação de cilindros de laminação para trabalho a frio

Pós-graduação em Engenharia Mecânica - FEG

Structural and optical properties of Er3+ doped SiO2-Al2O3-GeO2 compounds prepared by a simple route

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Mechanical and microstructural characterization of laser-welded joints of 6013-T4 aluminum alloy

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)