Continuous Nucleation
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Proposição de um Modelo Empírico para Determinação das Temperaturas Críticas Durante Resfriamento Contínuo em Zonas Termicamente Afetadas de Aços IF Soldados pelo Processo TIG
Resumo Aços IF são amplamente empregados na indústria automobilística. No decorrer das aplicações de soldagem, eles passam pela transformação de fase austenita (γ) → ferrita (α) que ocorre por nucleação e crescimento de grão e, em condições isotérmicas, é descrita pela equação JMAK. Todavia, as transformações de fases pós-soldagem ac
Soldag. insp.. Publicado em: 23/09/2019
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2. MODELING PARTICLE SIZE DISTRIBUTION IN HETEROGENEOUS POLYMERIZATION SYSTEMS USING MULTIMODAL LOGNORMAL FUNCTION
Abstract This work evaluates the usage of the multimodal lognormal function to describe Particle Size Distributions (PSD) of emulsion and suspension polymerization processes, including continuous reactions with particle re-nucleation leading to complex multimodal PSDs. A global optimization algorithm, namely Particle Swarm Optimization (PSO), was used for pa
Braz. J. Chem. Eng.. Publicado em: 2016-09
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3. Effect of Cr Additions on Ferrite Recrystallization and Austenite Formation in Dual-Phase Steels Heat Treated in the Intercritical Temperature Range
An experimental investigation was conducted using laboratory-processed low carbon Mn-Mo-Nb-Ti-B dual phase steel with additions of 0.2Cr or 0.6%Cr. This study investigates the effect of Cr additions on ferrite recrystallization and austenite formation during continuous annealing in the intercritical temperature range. It was found that moderate additions of
Mat. Res.. Publicado em: 23/02/2016
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4. Microstructure Observation of Naturally Aged Thixoforming ZA27 Alloy
The microstructure of the thixoformed ZA27 alloy naturally aged for 5 years has been observed and analyzed. The results indicate that most of the original β + η laminar eutectics have changed into the structures that small α particles uniformly distribute in η phase matrix. Both the β phase and α’ phase have also decomposed. It is suggested that a co
Mat. Res.. Publicado em: 24/11/2015
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5. Crystallization of II-VI semiconductor compounds forming long microcrystalline linear assemblies
In this work we report the formation of long microcrystalline linear self-assemblies observed during the thin film growth of several II-VI compounds. Polycrystalline CdTe, CdS, CdCO3, and nanocrystalline CdTe:Al thin films were prepared on glass substrates by different deposition techniques. In order to observe these crystalline formations in the polycrystal
Mat. Res.. Publicado em: 01/02/2013
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6. Obtaining and microstructualand mechanical characterization of Ti-Nb-Sn alloys applied as biomaterial / Obtenção, caracterização microestrutural e mecanica de ligas Ti-Nb-Sn aplicadas em implantes ortopedicos
This work deals with preparation, processing and microstructural and mechanical characterization of ß type Ti-Nb-Sn alloys aiming the manufacturing of orthopedic devices for implants. Ti samples containing Nb at levels of 25, 30 and 35 wt % and Sn at levels of 2, 4 and 8 wt % were prepared by arc melting, homogenized at 1000ºC/8 h and plastically deformed
Publicado em: 2009
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7. Filmes de diamante nanocristalino infiltrados em substratos de silício poroso através das técnicas CVD/CVI / Nanocrystalline diamond films infiltrates in porous silicon substrate by CVD/CVI Processes
The growth of nanocrystalline diamond films (NCD) on porous silicon (PS) substrate was studied using high resolution scanning electron microscopy, high resolution X-ray diffraction, X-ray photoelectron spectroscopy and Raman scattering spectroscopy. The NCD/PS films resulted in a composite material, with great potential for electrochemical application, mainl
Publicado em: 2009
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8. Kinetics of barium sulphate reaction crystallization in crystallizers with internal circulation
Kinetic calculation results describing the observed nucleation and growth rates of barium sulphate crystals precipitated in an integrated reaction-crystallization process in a barium sulphate-ammonium chloride-water system are presented and analyzed. The scope of experiments included two continuous model DTM-type crystallizers (Draft Tube Magma) with interna
Brazilian Journal of Chemical Engineering. Publicado em: 2008-06
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9. Efeito da nucleação de grãos nas previsões do modelo multifásico para a solidificação equiaxial. / Effects of grain nucleation on the predictions of the multiphase model for equiaxed solidification.
A multiphase mathematical model for the equiaxed solidification of binary alloys was proposed in the present work to predict the effects of the cooling rate and the average solute concentration on the final average grain size. The mathematical model was based on the concept of the grain envelope and on the conservation of energy, mass and chemical species. A
Publicado em: 2006
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10. Evolução da microestrutura e da textura durante o processamento de chapas da liga Al-Mn-Fe-Si (3003) produzidas por lingotamento contínuo: um estudo comparativo com o processo semi-contínuo. / Microstructure and texture evolution of the Al-Mn-Fe-Si (3003) aluminum alloy produced from continuous casting process: comparative analysis with semi-continuous casting process.
The main reason for the development of this PhD Thesis was to compare the microstructures and textures of the 3003 aluminum alloy produced from continuous and semi-continuous casting processes. The roll caster process (continuous casting) has been increasingly used in the aluminum industry. Products usually obtained by means of heavy rolling operations in th
Publicado em: 2005
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11. Development of alternative methods to the assessment of the creep fracture resistance of polyethylene resins used for the extrusion of water pipes. / Desenvolvimento de métodos alternativos para a avaliação da resistência à fratura por fluência de resinas de polietileno utilizadas para a extrusão de tubos de água.
Polyethylene has been largely used in potable water distribution systems, mainly in service lines. This polymer offers many advantages over its competitors: flexibility, low cost, ease installation and corrosion resistance. Pipes made with high density polyethylene HDPE, the generic designation of the material in the sanitation industry in Brazil fail
Publicado em: 2005
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12. Raman analyses of residual stress in diamond thin films grown on Ti6Al4V alloy
The stress evolution in diamond films grown on Ti6Al4V was investigated in order to develop a comprehensive view of the residual stress formation. Residual stress is composed of intrinsic stress induced during diamond film growth and extrinsic stress caused by the different thermal expansion coefficients between the film and substrate. In the coalescence sta
Materials Research. Publicado em: 2003-01