Copper Alloys
Mostrando 13-24 de 59 artigos, teses e dissertações.
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13. Efecto del tratamiento sub-cero sobre la microestructura y dureza de fundiciones blancas alto cromo
ABSTRACT The effect of the sub-zero treatment temperature on the transformation of retained austenite to martensite in two high chromium white cast irons (ASTM A532 Class II Type B) was studied. The sub-zero treatment applied to each alloy in the as cast condition was performed at -40, -65 and -180 ° C for 10 minutes; after the holding time was completed th
Matéria (Rio J.). Publicado em: 19/07/2018
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14. An Experimental Study of the Solidification Thermal Parameters Influence upon Microstructure and Mechanical Properties of Al-Si-Cu Alloys
Metals solidification involves the transformation of the molten metal back into the solid state. Solidification structures impact heavily on the final product's characteristics. The microstructure effects on metallic alloys properties have been highlighted in various studies and particularly the dendrite arm spacing influence upon the mechanical properties s
Mat. Res.. Publicado em: 18/06/2018
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15. Thermomechanical Modelling of FSW Process Using a Cylindrical Tool in an Aluminum Alloy Alclad AA 2024-T3
The Friction Stir Welding Process (FSW/P) is an innovative technique to join metals using the plasticity, not occurring the melting. It was initially applied in aluminum alloys, but recently it has been extended to other materials, for example, copper, steel alloys, polimers and others. In this work it is analyzed the thermo mechanical modelling of the energ
Mat. Res.. Publicado em: 07/05/2018
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16. Nickel-Copper Alloys Modified Electrodes: an Electrochemical Study on their Interfacial and Supercapacitive Properties
In this manuscript, we report the electrodeposition of nickel-copper alloys in a two steps methodology. Firstly, the copper electrode is oxidized to generate Cu2+ ions followed by the reduction of both Ni2+ and Cu2+. The electrodes were further cycled in KOH to convert the metallic alloy into the respective electroactive hydroxide. This methodology created a
J. Braz. Chem. Soc.. Publicado em: 2017-09
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17. Analysis of Compositional Modification of Commercial Aluminum Bronzes to Obtain Functional Shape Memory Properties
In copper-based shape memory alloys (SMAs), some exceptional phenomena, such as the shape memory effect (SME) or superelasticity (SE), are observable. However, commercial aluminum bronzes, Cu3Al-based alloys, do not present these functional properties (SME and/or SE) in their original state. Thus, since one of the main copper-based SMA systems is the Cu-Al-N
Mat. Res.. Publicado em: 17/08/2017
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18. Analysis of Spinodal Decomposition in Al-Zn and Al-Zn-Cu Alloys Using the Nonlinear Cahn-Hilliard Equation
The phase field model based on the nonlinear Cahn-Hilliard equation was applied to analyze the spinodal decomposition process in Al-Zn and Al-Zn-Cu alloys. Partial differential equations were solved using the explicit finite difference method for the Al- 20, and 35 at. % Zn alloys aged at temperatures between 25 and 100 °C for times from 10 s to 2000 s and
Mat. Res.. Publicado em: 20/03/2017
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19. Action of Antimicrobial Copper on Bacteria and Fungi Isolated from Commercial Poultry Hatcheries
ABSTRACT Since 2008, when the US Environmental Protection Agency (EPA) registered copper and its alloys as an antimicrobial agent for contact surfaces, research has demonstrated their antimicrobial activity. The aim of this study was to evaluate the efficacy of antimicrobial copper against bacteria and fungi isolated from commercial poultry hatcheries in ord
Rev. Bras. Cienc. Avic.. Publicado em: 2016-12
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20. Fabricación de vidrios metálicos base cobre: evolución de las fases durante el procesode aleación mecánica
ABSTRACTIn this study, different, copper-based materials were fabricated under equal milling conditions (SPEX 8000D, argon atmosphere, stearic acid, BPR=10:1) and variable amounts of time, from 1 to 120 hours, in order to compare the microstructural changes during the process. The materials were: Pure copper; Cu-Ni alloys; Cu-Zr alloys; and Cu-Ni-Zr alloys.
Matéria (Rio J.). Publicado em: 2015-09
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21. Streptococcus mutans adhesion and releasing of metallic ions in dental alloys
AIM: To evaluate the adherence of Streptococcus mutans to the surface of the amalgam and copper/aluminum alloy samples and also evaluate the release of metallic ions. METHODS: The prepared medium was changed every 72 h and analyzed by atomic absorption spectrophotometer. Samples were removed from the prepared medium at 15, 30, 48 and 60 days. RESULTS: The r
Braz. J. Oral Sci.. Publicado em: 2015-03
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22. The Evolution of the Niobium Production in Brazil
Niobium (Nb) was initially applied in the industry in 1933 to stabilize stainless steels against intergranular corrosion. Around 1970, niobium started to be used in many technological applications, especially in heat treatments at high temperatures, in the form of superalloys and, over the past four decades, Nb has been employed on an industrial scale. Durin
Mat. Res.. Publicado em: 2015-02
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23. Occurrence of sulphate reducing bacteria (SRB) associated with biocorrosion on metallic surfaces in a hydroelectric power station in Ibirama (SC) - Brazil
The aim of this study was evaluate, two methods for the detection and identification of sulphate reducing bacteria (SRB): ML medium and PCR with specific primers for SRB groups. SRB were detected through the selective medium only on carbon steel, which showed corrosion. Employing specific PCR primer, SBR were detected from all the metallic components assayed
Braz. arch. biol. technol.. Publicado em: 2013-10
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24. Study of the Al-Si-X system by different cooling rates and heat treatment
The solidification behavior of the Al-12.6% Si (A1), the hypereutectic Al-20%Si (A2) and the Al-20%Si-1.5% Fe-0.5%Mn (A3) (in wt. (%)) alloys, at different cooling rates is reported and discussed. The cooling rates ranged between 0.93 °C/s and 190 °C/s when cast in sand and copper wedge-shaped molds, respectively. A spheroidization heat treatment was carri
Mat. Res.. Publicado em: 30/08/2012