Microstructures
Mostrando 25-36 de 292 artigos, teses e dissertações.
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25. On the observation of extended microstructures and localized deformations in granular materials - A feature of excat quasi-convex energy envelope
Abstract In this paper a most promising scope of the exact quasiconvex energy envelope in modeling the granular materials with microstructures is presented. This study shows that it is possible to observe both the extended microstructures and localized deformations in granular materials using a variational model based on the mathematical relaxation theory. T
Lat. Am. j. solids struct.. Publicado em: 25/04/2019
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26. Mechanical Properties and Microstructural Evolution of CuZn Alloys via Pre-Torsional Deformation
Mechanical properties and microstructural evolution of Cu-10wt.%Zn and Cu-30wt.%Zn alloys after pre-torsional deformation have been investigated in this study. The results indicated that pre-torsional deformation can significantly enhance the strength of both Cu-10wt.%Zn and Cu-30wt.%Zn alloys without changing their shape and size, but with the sacrifice of
Mat. Res.. Publicado em: 18/04/2019
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27. Investigation on the Wear Properties of Ti/TiC/TiN Composite Coatings Prepared by Powder Cored Wires Through TIG Method at Nitrogen Atmosphere on Titanium Substrate
In this present study, Tungsten Inert Gas (TIG) welding and powder filled cored wires with nitrogen shielding gas were utilized to produce TiC and TiN surface composite coatings on the titanium (Ti) sheet substrate. The TIG procedure was done at same welding parameters for all of prepared samples. Phase analysis and microstructures were done by X-ray Diffrac
Mat. Res.. Publicado em: 15/04/2019
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28. Effects of Forming Processes on Microstructures and Mechanical Properties of A356 Aluminum Alloy Prepared by Self-inoculation Method
Semisolid slurry of A356 aluminum alloy was prepared by Self-Inoculation Method (SIM), and the microstructures and solidification behavior of rheo-forming process in different forming processes were researched. The results indicate that semisolid slurry of A356 aluminum alloy can be prepared by Self-Inoculation Method at 600ºC. Primary α-Al particles with
Mat. Res.. Publicado em: 11/04/2019
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29. Microfacies and diagenetic evolution of the limestones of the upper part of the Crato Formation, Araripe Basin, northeastern Brazil
Abstract This paper presents the results of a petrographic and diagenetic study of the laminated limestones of the upper part of the Aptian to Albian Crato Formation, northeast of Brazil. The applied techniques were optical microscopy, cathodoluminescence and scanning electron microscopy (SEM) coupled to a wavelength-dispersive spectrometer (WDS). Petrograph
Braz. J. Geol.. Publicado em: 08/04/2019
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30. Microstructure and Mechanical Properties of AA6061/AZ31B/AA6061 Composite Plates Fabricated by Vertical Explosive Welding and Subsequent Hot Rolling
In this study, three-ply Al/Mg/Al composite plates were successfully achieved by vertical explosive welding (EXW) method. After EXW, the sound joints were obtained. Then thin three-ply Al/Mg/Al EXWed composite plates with the thickness of 1.78 mm were achieved by hot rolling. The influence of annealing on the interface microstructures and mechanical properti
Mat. Res.. Publicado em: 04/10/2018
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31. Effect of Growth Velocity and Zn Content on Microhardness in Directionally Solidified Al-Zn Alloys
In this study, Al-xZn (x=1, 3, 5, 7, 10 and 20 wt. %) alloys were prepared using metals of 99.99% high purity in the vacuum atmosphere. These alloys were directionally solidified upward with a constant temperature gradient, G (10.3 K/mm) and different growth velocities (V) between 8.25 and 165 µm/s in the directional solidification apparatus. The experiment
Mat. Res.. Publicado em: 13/09/2018
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32. Heat Treatment of Sintered Valve Seat Inserts
The characterization of sintered valve seat inserts (VSIs) after being subjected to different heat treatment operations has been carried out. The VSIs were obtained from three different alloys by mixing iron powder with AISI M3:2, AISI M2 high-speed steels, and AISI D2 tool steel. After sintering, the VSI were quenched in air followed by double tempering at
Mat. Res.. Publicado em: 02/08/2018
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33. Estabilidad de la austenita retenida bajo condiciones de deformación en aceros multifásicos con bainita nanoestructurada
ABSTRACT A steel with nominal composition 0.25C, 1.9Si, 0.63Mn, 1.5Cr was manufactured using an induction furnace. The as-cast alloy was homogenized and the temperatures of austenite start (AC1) and finish (AC3) during heating were determined by dilatometric analyses. Two intercritical austenitization temperatures were selected, which were used to perform pa
Matéria (Rio J.). Publicado em: 19/07/2018
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34. Estudio de la formabilidad en caliente de aleaciones de titanio a través del ensayo de torsión y su aplicación a la optimización de procesos de forja y extrusión
ABSTRACT In the development of hot metal forming, the metallic products must comply with the requirements imposed by current standards. In some cases, the required microstructure can only be obtained through thermomechanical processing. With titanium and its alloys, small ranges of good workability are an additional difficulty. In this work the hot-workabili
Matéria (Rio J.). Publicado em: 19/07/2018
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35. Determinación de los parámetros de austenización intercrítica para el desarrollo de aceros multifásicos mediante análisis dilatométrico
ABSTRACT The Multiphase steels are materials with exceptional mechanical properties including high strength, excellent ductility and hardening coefficient and good conformability. These properties are related with the microstructure, which can be a combination of ferrite and martensite (Dual phase steels) or more complex microstructures with ferrite, bainite
Matéria (Rio J.). Publicado em: 19/07/2018
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36. Movimiento de las interfases durante la solidificación horizontal de aleaciones estaño-zinc
ABSTRACT Solidification processing is one of the important routes to produce materials, especially metals and alloys. The parameters for the transformation from liquid to solid, such as the temperature gradient, the growth rate, the cooling rate, the interphase velocity, vary from process to process and in one process also as a function of time and space. Th
Matéria (Rio J.). Publicado em: 19/07/2018