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Showing 1 to 20 of 26 for “"Engenharia metalúrgica e de materiais"”.
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Eletro-oxidação de efluente contendo nitrogênio amoniacal na presença de cloreto
… effluent rich in ammoniacal nitrogen and chloride. A sample from the port of Tubarão, Vitória / ES, was used for the tests. The main objective was recovering ammoniacal nitrogen of the sample. In this work two electrolytic cells, with and without Nafion-424 cationic membrane, were tested. In …
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Estudo da influência das variáveis de síntese na morfologia e espessura da camada de nanofios de niobato de sódio suportado em nióbio
… supported on niobium platelets. An experimental design was planned to evaluate temperature, alkali concentration and reactional time influence on the produced material. It was analyzed by characterization techniques, such as scanning and transmission electron microscopies, to characterize its …
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Caracterização por ensaios magnéticos não destrutivos de aços HP provenientes de fornos de reforma
This study aims to characterize, through magnetic tests, the different aging stages to which are submitted HP austenitic steel tubes when operating in oil industry's reformer furnaces. The assumption adopted here is that aging causes microstructural transformations that modify their magnetic …
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Influência de Recobrimento vítreo e ataque com ácido fluorídrico na topografia final da superfície Y-TZP e qualidade adesiva entre Y-TZP e cimento resinoso
… por vidro protocol. YTZP samples were then divided into 3 groups according to the surface treatment. The three groups had the surface covered with a low melting glass containing silica in their composition. In group 1 the glass was partially removed with 10% hydrofluoric acid for 30 minutes. In …
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Produção, caracterização e avaliação in vitro de filmes finos de vidro niobo-fosfato por deposição a laser pulsado
… bioactive glass (CaF2-CaONb2O5-P2O5) films were deposited by pulsed laser deposition (PLD) on Ti substrates aiming to enhance its bioactivity and osseointegration. Samples were analyzed by SEM, EDS, XPS, XRD, XRF, AFM, profilometry, scratch test, focal contact and cell proliferation and …
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Filmes de FePt para dispositivos da spintrônica
The present study deals with magnetic and transport properties in the L10 FePt compound. The compound has tetragonal structure and strong magnetocrystalline anisotropy. Films were prepared by sputtering. For measuring Tunnel Anisotropic Magnetoresistance (TAMR), FePt/AlOx/Au trilayers were …
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Interação do hidrogênio com a microestrutura dos aços inoxidáveis supermartensíticos sob regime elástico
… addition of alloy elements (like nickel and molybdenum) and reduced carbon. They present higher corrosion resistance under CO2, H2S, and chloride rich environments, and higher mechanical resistance and toughness. Therefore, under severe conditions, properties loss and hydrogen embrittlement may …
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Análise da Utilização de Produtos Ambientalmente Amigáveis como Inibidores de Corrosão em Ambientes Contendo CO2
… control. However, most substances are non-biodegradable synthetic chemicals and can be hazardous to living beings and the environment. The present work studied the influence of three environmentally-friendly components on the API 5L X65 steel corrosion inhibition in CO2-saturated 3.5 wt.% NaCl …
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Estimativa de vida residual de rotores de turbinas a vapor expostos aos mecanismos de dano por fluência e fadiga
… most of the times, in cyclic regime, in order to supply seasonal demand peaks. This operational behavior may lead in a series of non predicted damages and losses, because most of the plants are designed to operate in base load, with the least number of start/stop cycles as possible. The …
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Caracterização do efeito whitening em polifluoreto de vinilideno (PVDF) por ensaio ultrassônico
… known as stress whitening. This study was intended to characterize qualitatively and quantitatively the whitening effect of polyvinylidene fluoride (PVDF) samples using the ultrasound test. Therefore, the techniques which used were the measurements of sonic velocity, spectral Fourier analysis, …
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Modelling and optimization of green pellets classification on roller screens using the discrete element method
… and bulk properties of the green pellets are determined in physical tests for calibration and validation by comparison with industrial data of contact models that reproduce with verisimilitude the movement of these solids. According to the results, the JKR model was the one that best fitted …
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Ligas à base de ferro-titânio para aplicações de armazenamento de hidrogênio
In the last decades, some countries have changed their energy matrix motivated by environmental and economic issues. Hydrogen (H2) stands out as a source of clean energy and your storage in the form of hydrides in metal alloys is promising. Among these, titanium-iron alloys (TiFe) present low cost …
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Efeito do envelhecimento e da geração de “whitening” no comportamento mecânico do PVDF
The polyvinylidene (PVDF) is a polymer with high chemical and mechanical resistence, for this reason is being largely used in the composition of flexible pipes used in petroleum production offshore, acting as sealing layer. One effect named whitening can appear in the material, being characterized …
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Avaliação da resistência mecânica e da molhabilidade de fibras de aramida após tratamento com plasma de argônio
… the value of the strength resistance begins to decay. The plasma treatment also increased the roughness of the fiber surface and caused the inclusion of incrustations on it, indicating a possible improvement in the mechanical interlock between fiber and matrix.
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Estudo do mecanismo de corrosão pelo CO2 em aço carbono via técnicas eletroquímicas em condições que incluem alta pressão e temperatura
CO2 corrosion is one of the major forms of deterioration of carbon steel in the oil and gas industry. The presence of the carbon dioxide accelerates the corrosion of carbon steel if compared to the medium containing strong acid with the same pH and this scenario makes even more relevant the …
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Avaliação mecânica e microestrutural pós forjamento da liga de níquel 718 com adição de ítrio
… Y content of 50 and 60%. The Yttrium addition decrease the oxygen, nitrogen and sulfur contents. The low-Y alloy presented an increase of the grain size, while the high-Y alloy presented a refined grain size due to the intense precipitation of second phase particles. The microstructural …
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Estudo do processamento termomecânico de liga experimental de zircônio e seu efeito nas propriedades mecânicas e formação de hidretos
… of the reactor leads to the formation of hydrides, dependent on the presence of crystalline discontinuities and on the texture of the material. This work aimed to validate the thermomechanical processing of an experimental zirconium alloy produced at COPPE, as well as to investigate its effects …
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Ensaios e metodologias de análise de integridade para equipamentos em aço baixa liga sujeitos à fragilização por hidrogênio
… with different testing methodologies in order to obtain useful parameters. Rising step loading tests were performed to obtain fracture toughness values of a 780 MPa yield strength quenched and tempered AISI 4340 low alloy steel in brine solution with cathodic protection. Results obtained …
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Estudo da permeação de hidrogênio e fragilização pelo hidrogênio de um aço API 5L X80
… corrosive environment containing hydrogen sulphide (H2S). Although many efforts have been made to predict and understand those phenomena, the mechanisms involving H2S corrosion combined with applied strain still not entirely understood. In addition, the growth of iron sulphides scales can take an …
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Estudo da fragilização por hidrogênio de um aço inoxidável super martensítico através da teoria da redução da energia interfacial
… of steels. Throughout the years several models were proposed to explain this phenomenon. The aim of this work is to study the hydrogen embrittlement by using the theory of interfacial energy reduction. In order to apply this theory super martensitic stainless steel was used. This alloy is …
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