Coarse Grain
Mostrando 13-24 de 54 artigos, teses e dissertações.
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13. The Neostratotype of Itapecuru Formation (Lower-Middle Albian) and Its Impact for Mesozoic Stratigraphy of Parnaíba Basin
Abstract Abstract: This study defines the neostratotype of the Lower-Middle Albian Itapecuru Formation in the Parnaíba Basin, Northeast Brazil. In this sedimentary succession along the right bank of the Itapecuru River near the Itapecuru-Mirim City, Maranhão State, three lithofacies associations are recognized. The first is silty claystone with some very f
An. Acad. Bras. Ciênc.. Publicado em: 06/05/2019
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14. New mathematical modelling for grain size distribution adjustment in concrete
Abstract Concrete used in civil engineering is a composite obtained from the combination of coarse and fine aggregates, cement and water, and its cost and quality are normally associated to the proportion of its constituents (ceramic formulation), as well as the reduction of water consumption. The aggregates used in concrete may have diverse origins, and the
Cerâmica. Publicado em: 2019-01
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15. Mineralogy, magnetic susceptibility and geochemistry of Fe-rich Oxisols developed from several parent materials
ABSTRACT: Fe-rich Oxisols on mafic rocks in Brazil generally have high magnetic susceptibility with high contents of some trace elements. These are taxonomically similar soils; however, differences in magnetic and geochemical properties may affect agricultural or environmental usability and subsequent management. This study investigated the pedogenesis of Fe
Sci. agric. (Piracicaba, Braz.). Publicado em: 2018-09
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16. The Effectiveness of Back Pressure in Superplastic Blow Forming of Aluminum Alloy AA 5083 Performed at Very Favorable Conditions for Cavitation Growth
Many components for aerospace and automotive industries are currently manufactured using superplastic forming, being the fine-grained aluminum alloy AA5083 widely used for this proposes. However, the development of cavitation voids is inherent in this process and reduces the ductility of the alloy. Back pressure can be used to diminish the growth of cavitati
Mat. Res.. Publicado em: 26/07/2018
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17. Estudio de la microestructura de un cordón de soldadura de un acero P91 mediante microscopía electrónica de transmisión
ABSTRACT In the present work the microstructural characterization of a single-pass weld of 9Cr1MoVNb P91 steel performed by the flux-cored arc welding (FCAW) process in the “as welding” condition has been carried out by means of transmission electron microscopy. P91 steel offers a good weldability, but the mechanical properties of the welded joints are f
Matéria (Rio J.). Publicado em: 19/07/2018
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18. Solution Treatment Behaviors of 6061 Aluminum Alloy Prepared by Powder Thixoforming
Powder thixoforming (PTF) was a promising processing technology that can be used to fabricate high strength particle reinforced aluminum matrix composites, and a pioneer 6061 matrix alloy was fabricated utilizing PTF to investigate its solution treatment behaviors. A comparison study with traditional permanent mold cast (PMC) 6061 alloy disclosed that PTF al
Mat. Res.. Publicado em: 07/05/2018
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19. Growing Periandra mediterranea on post-mining substrate: native Fabaceae with potential for revegetation of degraded rupestrian grasslands in Brazil
ABSTRACT Recovery of degraded areas of rupestrian grasslands is hampered mainly by the limited knowledge regarding substrate management and the biology of native species suitable for revegetation of these areas. The aim of our study was to examine the establishment and growth of Periandra mediterranea in different textures of lateritic substrate from a minin
Acta Bot. Bras.. Publicado em: 15/01/2018
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20. Influence of Heat Input and Filler Metal on Mechanical Properties and Microstructure of Microalloyed High Strength Steel Welded by FCAW
AbstractCurrently, microalloyed high strength steels are being widely used to replace C and C-Mn steels for their advantages in terms of mechanical properties, corrosion resistance and weldability, allowing weight reduction of vehicles and structures without impairing their strength. When these steels are welded, the welding heat cycle causes microstructural
Soldag. insp.. Publicado em: 2015-06
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21. Corrosion Behavior of Coarse- and Fine-Grain Ni Coatings Incorporating NaH2PO4.H2O Inhibitor Treated Substrates
Plain carbon steel substrates were treated with NaH2PO4.H2O inhibitor for 24 hours and coated with Ni using dc and pulse electrodeposition in standard Watt’s bath. The effect of dc and pulse electrodeposition, on the microstructure and corrosion properties of Ni coatings in 3.5 wt% NaCl solution was studied. The effect of inhibitor on the deposition proces
Mat. Res.. Publicado em: 2015-02
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22. Effects of austenitization temperature on the microstructure of 15BCr30 and PL22 boron steels
This paper studies boron precipitation and segregation at austenitic grain boundaries for low carbon boron steels types: PL22 and 15BCr30. The following parameters were evaluated: percentage of martensite/bainite, size and nucleation sites of austenitic grains and precipitates sizes. Three austenitization temperatures were studied (870, 1050 and 1200 °C). T
Mat. Res.. Publicado em: 16/04/2013
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23. Normalizing effect on fatigue crack propagation at the heat-affected zone of AISI 4140 steel shielded metal arc weldings
The fractography and mechanical behaviour of fatigue crack propagation in the heat-affected zone (HAZ) of AISI 4140 steel welded using the shielded metal arc process was analysed. Different austenitic grain size was obtained by normalizing performed at 1200 °C for 5 and 10 hours after welding. Three point bending fatigue tests on pre-cracked specimens along
Mat. Res.. Publicado em: 02/04/2013
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24. Microhardness and EBSD microstructure mapping in partially-pressed al and cu through 90º ECAP die
Equal-channel angular pressing (ECAP) is widely recognized as an effective method for processing ultrafine-grained and even nanostructured materials. Important details on processes occurring in the die intersections can be obtained by mapping the microhardness and EBSD microstructures in partially-pressed aluminum and copper through the 90º die of ECAP. Pre
Mat. Res.. Publicado em: 08/03/2013