Phase Transformation
Mostrando 25-36 de 574 artigos, teses e dissertações.
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25. Evolución microestructural durante el envejecimiento a alta temperatura de una aleación 35Ni-25Cr-Nb
ABSTRACT The dendritic-type microstructure of the 35Ni-25Cr-Nb alloy, in the as-cast condition, consists of an austenitic matrix and two types of eutectic primary carbides; Nb-rich MC type and Cr-rich M23C6 type both presents in interdendritic edges and grain boundaries. During aging at 800ºC for different times, M23C6 type secondary carbides precipitate in
Matéria (Rio J.). Publicado em: 19/07/2018
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26. Método innovador de ensayos de impacto en altas temperaturas aplicado en aceros al carbono
ABSTRACT In this paper, an innovative method of impact tests at high temperature on sub-size Charpy V notched specimens is applied. The innovation lies in the method of heating the specimen, which is performed in situ on a Charpy impact machine type by alternating electrical current through the specimen. The specimens are heated in a few seconds (v=32 ºC/s)
Matéria (Rio J.). Publicado em: 19/07/2018
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27. Microscopía fototérmica para el estudio de transformaciones de fase
ABSTRACT A novel system allowing a high spatial resolution mapping of the thermal diffusivity as a function of temperature up to 1800 K is presented. The system is based on a photothermal technique recently developed by the group, consisting in measuring, with a probe laser beam, the curvature induced by local heating with a modulated pump laser. A microscop
Matéria (Rio J.). Publicado em: 19/07/2018
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28. Influence of defects on the irreversible phase transition in the Fe-Pd doped with Co and Mn
ABSTRACT The appearance of BCT martensite in Fe-Pd-based ferromagnetic shape memory alloys, which develops at lower temperatures than the thermoelastic martensitic transition, deteriorates the shape memory properties. In a previous work performed in Fe70Pd30, it was shown that a reduction in defects density reduces the non thermoelastic FCT-BCT transformatio
Matéria (Rio J.). Publicado em: 19/07/2018
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29. Estabilidad de las fases U3Si5, USi2-x y USi2 al incorporar Al en solución. Experiencias de calorimetría diferencial de barrido
ABSTRACT U(Mo) alloys are being studied to be applied as a fuel for research and test reactors. When U(Mo) particles are dispersed in an Al matrix, it is known that an interdiffusion during fabrication process and / or irradiation. In this sense, irradiation tests have shown that this IL has a bad behavior under irradiation coming up the addition of Si to Al
Matéria (Rio J.). Publicado em: 19/07/2018
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30. Estudio del comportamiento en enfriamiento continuo del acero martensítico ferrítico de activación reducida F82H
ABSTRACT 9% Cr martensitic-ferritic steels are currently the privileged candidates to manufacture structural components of the so-called Generation IV nuclear fission reactors, because they exhibit very good thermophysical and mechanical properties under neutron irradiation. Along with them, the so-called Reduced Activation Ferritic-Martensitic steels (RAFM�
Matéria (Rio J.). Publicado em: 19/07/2018
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31. Characterization of reverse martensitic transformation in cold-rolled austenitic 316 stainless steel
ABSTRACT In this work the reversion of the strain-induced ?’-martensite to ?’-austenite was studied in a series of AISI 316 stainless steels (SS) specimens. The samples were submitted to 63% reduction in thickness by rolling at a temperature of -70ºC, to achieve high martensite content. The reversion of martensite to austenite was made by means of isoch
Matéria (Rio J.). Publicado em: 19/07/2018
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32. Releasing systems for aerospace industry based upon Shape Memory Alloys: characterization of materials for actuators
ABSTRACT Releasing and deployment maneuvers carried out during space satellites launching are usually performed by utilizing pyrotechnics loads. However, it is considered convenient to replace this technique by others not requiring explosives (Non Explosive Actuators-NEA). This is mainly due to the necessity of reducing high-shock and vibrations induced leve
Matéria (Rio J.). Publicado em: 19/07/2018
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33. Desdoblamiento de la transformación martensítica en un acero F82H de activación neutrónica reducida
ABSTRACT One of the most promising solutions to global energy supply is nuclear fusion. This process, which is implemented in nuclear fusion reactors (from which one of the first designs was the Tokamak), involves deuterium-tritium plasmas at very high temperature, confined in vacuum chambers of toroidal shape under the influence of strong magnetic fields. T
Matéria (Rio J.). Publicado em: 19/07/2018
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34. Effect of Martensitic Transformation on Elastic Modulus Anisotropy of Ti-6Al-4V Alloy
The Young's modulus (E), Poisson's ratio (ν) and anisotropy parameter (AG) of α' phase, which obtained from different solution treatment and water quenching temperature, were investigated using first-principles calculations based on density functional theory (DFT). The calculation results showed that the Z-axis value of the elastic modulus of α' phase was
Mat. Res.. Publicado em: 25/06/2018
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35. Ontogenetic shape changes and sexual dimorphism in Aegla marginata Bond-Buckup and Buckup, 1994
ABSTRACT A study on relative growth, sexual dimorphism and ontogenetic trajectory was carried out in a population of the aeglidAegla marginata coming from Barrinha River, Iguape River Basin, Tunas do Paraná, Paraná State, Brazil. The size the of morphological sexual maturity was estimated for males and females. The analysis of sexual dimorphism and ontogen
An. Acad. Bras. Ciênc.. Publicado em: 14/05/2018
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36. Effect of grinding and aging on subcritical crack growth of a Y-TZP ceramic
Abstract This study aimed to investigate slow crack growth (SCG) behavior of a zirconia ceramic after grinding and simulated aging with low-temperature degradation (LTD). Complementary analysis of hardness, surface topography, crystalline phase transformation, and roughness were also measured. Disc-shaped specimens (15 mm Ø × 1.2 mm thick, n = 42) of a ful
Braz. oral res.. Publicado em: 03/05/2018