Avaliação da resistência à corrosão da liga Ti-30Ta submetida a diferentes taxas de deformação visando aplicações biomédicas

This study aims to evaluate the corrosion resistance of Ti-30Ta alloy when subjected to different strain rates. Samples of the alloy Ti-30Ta were obtained from the melting of pure elements in the arc furnace in inert atmosphere (argon gas). Then, the samples were subjected to a thermal treatment and to cold worked to obtain bars. After forging, the samples were machined in accordance with ASTME9-09 standard for carried out compression tests. To microstructural characterization, samples were sectioned longitudinal and transversally and embedded in resin. After, the wet sanding and polishing were performed, followed by a chemical attack, in order to study the microstructure under an optical microscope. Microhardness was measured on the samples that were subjected to microstructural characterization by using microhardness tester. Phases were evaluated by x-rays diffraction. Corrosion tests were carried out to evaluate the influence of deformation on the corrosion resistance. Results show that microstructure was not influenced by deformation

Análise de integridade física de barragens de terra a partir da integração do método geofísico da eletrorresistividade com ensaios geotécnicos

Pós-graduação em Geociências e Meio Ambiente - IGCE

Colunas de Winogradsky com águas contaminadas por petróleo e derivados monitoradas por ensaios ecotoxicológicos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise de misturas solo-agregado reciclados de resíduos sólidos da construção civil, para fins de pavimentação de vias urbanas de baixo volume de tráfego

This work deals with the continuation of Scientific Initiation research initiated by Tamura (2012), which draws up a mixture of soil and recycled aggregate analysis for paving of low traffic volume roads using local materials from the Vale do Paraíba region. The main steps of the process were the soil and recycled aggregate characterization, along with grading tests and California Bearing Ratio (CBR) applied to the soil, the recycled aggregate and the mixture of soil and recycled aggregate; aiming their use as base and sub-base in paving urban roads. The results are discussed, emphasizing the mechanical behavior. The current results are compared with the results of IC Tamura research, taking decisions over this job to the final product best result. For a greater understanding of the work in general were described paving, its structure, its components and its physical behavior. It has been intended to emphasize the importance of the mixture of soil and recycled aggregate to meet the quality requirements and compliance with the specifications of current technical standards, in the context of durability, natural materials economy, decreases volume in landfills and cost reduction

Projeto de adaptação do sistema de injeção do túnel transônico para ensaios em bocais de foguete

In this work, the project of a new experimental facility to be installed at the Aerodynamics Division of the Institute of Aeronautics and Space is presented. This new facility will provide means to perform experimental campaigns to analyze the flow behavior at different rocket nozzle concepts using cold gas that will be obtained from a modification of the Pilot Transonic Wind Tunnel air system. The new installation will enable less expensive experiments in a more secure environment, since the cold gas experimental procedures do not demand fuel storage and burn and security procedures are much less severe. Furthermore, experiments can be carried with different types of sensors, commonly used in wind tunnel tests. Also, the optical access is facilitated enabling the use of optical techniques for the characterization of flow properties inside the nozzles, such as pressure and temperature sensitive painting. The full project design and the operation conditions will be showed, as also some technical considerations about the flor behavior in the facility

Determinação comparativa do grau de deformação plástica aplicado a componentes obtidos por conformação

The manufacturing process of components of Pressure Vessels has a great importance in the efficiency during the operation and life cycle of the equipment. Taking this into account, the objective of this dissertation was to analyze the methods to determine the strain rate in formed components by measuring the components themselves, and posterior results comparison with the values found in manufacturing standards of Pressure vessels. In this study the whole manufacturing process of a component from a pressure vessel, known as Head or End, was accompanied. Using the methodology obtained from literatures it was possible to execute the relative and logarithmic deformation measurements of these components and compare with the obtained results by means of equations presented in the Standards as AD-Merkblatt and ASME (for pressure vessels). The found results were also compared with the logarithmic methodology, taking into account the deformation of the empirical mesh and the thickness of the components studied. It is possible to conclude from this study that despite the existence of empirical methods of measurement of strain rate in components plastically formed, it is recommended the adoption in all situation of the component manufacturing standard. It can be noticed and explained during the development of this study and through the results found