Unidirectional Solidification
Mostrando 1-12 de 23 artigos, teses e dissertações.
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1. Transient Unidirectional Solidification, Microstructure and Intermetallics in Sn-Ni Alloys
The present research work examines the microstructural arrangements formed during the transient solidification of eutectic Sn-0.2wt.%Ni and hypereutectic Sn-0.5wt.%Ni alloys. Also, it examines their respective correlations with solidification thermal parameters: eutectic growth rate (VE) and eutectic cooling rate (ṪE); length scales of matrix and eutectic
Mat. Res.. Publicado em: 12/04/2018
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2. Predicting Secondary-Dendrite Arm Spacing of the Al-4.5wt%Cu Alloy During Unidirectional Solidification
Mechanical properties and performance of metallic materials depend on their microstructures. In order to develop engineering materials that match prescribed criteria and to enable design with multifunctional materials, it is essential to be able to predict their microstructural patterns, such as size, shape, and spacing of the dendritic structures observed i
Mat. Res.. Publicado em: 24/11/2016
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3. Effects of cellular growth on fatigue life of directionally solidified hypoeutectic Al-Fe Alloys
Al-Fe hypoeutectic alloys are a family of casting alloys characterized by cell growth, low cost and appreciable formability. It is well known that fatigue strength is a requirement of prime importance considering the nature of load typically observed during operations involving the risers used in oil extraction. The aim of this study is to examine the influe
Mat. Res.. Publicado em: 28/02/2014
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4. The columnar to equiaxed transition of horizontal unsteady-state directionally solidified Al-Si alloys
Experiments were conducted to investigate the influence of thermal parameters on the columnar to equiaxed transition during the horizontal unsteady-state directional solidification of Al-Si alloys. The parameters analyzed include the heat transfer coefficients, growth rates, cooling rates, temperature gradients and composition. A combined theoretical and exp
Mat. Res.. Publicado em: 18/02/2014
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5. Análise da evolução microestrutural e da formação de macrossegregação e microporosidade na solidificação unidirecional transitória de ligas ternárias Al-Cu-Si / Analysis of microestrutural evolution and formation of macrosegregation and microparasity in the unidirectional transient solidification of ternary Al-Cu-Si alloys
As ligas fundidas de alumínio vêm desempenhando um papel importante no crescimento da indústria metal-mecânica. Hoje, essas ligas são produzidas em vários sistemas e dezenas de composições. Destacamos as ligas do sistema ternário Al-Cu-Si que apresentam excelente fluidez, alta resistência mecânica e baixo peso, o que as tornam uma escolha adequada
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia. Publicado em: 01/02/2012
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6. Evolution of eutectic spacing during unidirectional solidification of Al-Ni alloys
Hypoeutectic Al-Ni alloys show a ductile phase α distributed with a β phase Al3Ni fragile where β serves as reinforcement of the structure of the material. The eutectic composition alloys obey the relationship: λ2.v = C, where λ is the eutectic spacing, v is a tip growth rate and C is a constant. The aim of this study is to establish correlations betwee
Materials Research. Publicado em: 27/05/2011
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7. Parametros termicos e estruturais em ferros fundidos cinzento e nodular solidificados em moldes de areia e unidirecionalmente / Thermal and structural parameters in gray and ductile cast irons solidified in sand molds and under unidirectional conditions
In the present work unsteady state unidirectional solidification of a hypoeutectic gray cast iron and of a eutectic ductile cast iron is applied to analyze the influence of the process parameters an the flake and nodule count. For comparison purpose some samples were cast in sand molds. The experimental results of temperature variation in the casting were us
Publicado em: 2009
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8. Transient solidification, microstruture and properties of Al-Ni alloys / Solidificação transitoria, microestrutura e propriedades de ligas Al-Ni
The development of optimized microstructures during the solidification stage of processing is of fundamental importance to the mechanical properties and to the performance of finished products of metallic alloys. In this study the kinetics of solidification and its effects on macro and microstructural parameters, as well as the consequent influence on the fi
Publicado em: 2009
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9. Effect of inoculation on the grain macrostructure of Al-Si alloys obtained by unidirectional solidification. / Efeito da inoculação na macroestrutura de grãos de ligas AI-Si obtidas por solidificação unidirecional.
The development of various industrial sectors, such as the automotive and the aerospace industry, demand premium aluminum castings with strict control of mechanical properties. To fulfill these requirements, the control of solidification processes and the knowledge of relations between the processing variables and the casting properties are necessary. The me
Publicado em: 2009
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10. Solidification microstructures and mechanical and corrosion resistances of dilute Pb-Sn alloys / Microestrutura de solidificação e resistencias mecanicas e a corrosão de ligas Pb-Sn diluidas
Lead-acid batteries manufacturers have modified the manufacturing processes and the chemical composition of alloys used in battery grids in order to decrease their weight as well as to reduce the production costs, and to increase the battery life-time cycle and the corrosion-resistance. The morphological microstructures characterized by cellular and dendriti
Publicado em: 2009
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11. Purificação de silicio metalurgico por fusão zonal horizontal em forno de feixe de eletrons / Purification of metallurgical silicon by horizontal zone melting in an electron beam furnace
The search for renewable energy sources has caused a boom in the production of solar cells in this decade, which rose from 0.3 GW in 2002 to 6.0 GW in 2008, totaling 37 billion dollars in 2008. The production of Electronic Grade Silicon (SiGE) increased 127% from 2007 to 2008, and approximately 90% of solar cells produced nowadays use SiGE, which is responsi
Publicado em: 2009
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12. Microestrutura de solidificação e propriedades mecanicas de ligas Sn-Zn para soldagem e recobrimento de superficies / Solidification microstructure and mechanical properties of Sn-Zn alloys for welding and deposition
Sabe-se que existem tendências de leis e diretrizes que restringem o uso e aplicação de certas substâncias perigosas utilizadas em processos de fabricação de componentes em geral. Como exemplo, podem-se citar produtos contendo cádmio, mercúrio, cromo hexavalente, bifenilos polibromatos, éteres difenil-polibromato e chumbo. Devido a essas restriçõe
Publicado em: 2008