Metastable Alloys
Mostrando 1-12 de 26 artigos, teses e dissertações.
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1. Effect of Squeeze Casting on Microhardness and Microstructure of Al-3Cu-xSi Alloy
Aluminum alloys of the ANSI series 319 present Si and Cu as the main alloying elements and the mechanical strength of these alloys can be improved by the precipitation of the metastable Al2Cu phase. Squeeze Casting is a casting process in which the cast metal is deposited in a metal mold and solidified under certain pressure exerted by a punch. This process
Mat. Res.. Publicado em: 30/09/2019
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2. Effects of composition on transformation temperatures and microstructure of Ni-Ti-Hf shape memory alloys
Abstract High transformation temperature shape-memory alloys (HTSMA) usually present a martensitic transformation temperature (Ms) starting at 100 ºC. That is the case of high nickel Ni-Ti-Hf alloys. This article presents experimental results obtained from arc melting of Ni50Ti50-XHfX .at% (X = 8, 11, 14, 17 and 20 .at%) alloys. This process homogenized eve
REM, Int. Eng. J.. Publicado em: 2019-06
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3. Identificación de precipitados en aleaciones U-Nb-Zr tratadas térmicamente a 850 ºC
ABSTRACT At the present, the international goal is to develop and qualify a very high U density fuel for high flux research reactors. The selected U-alloy must present an isotropic crystalline structure at the end of the fuel fabrication process. These types of structures exhibit stable behavior under irradiation. In particular, it is wanted to retain as met
Matéria (Rio J.). Publicado em: 19/07/2018
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4. 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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5. Impact of Alloy Composition and Thermal Stabilization on Martensitic Phase Transformation Structures in CuAlMn Shape Memory Alloys
Alloys of CuAlMn are known as cheap, high strength shape memory alloys with an excellent damping capacity within their austenitic-martensitic phase transformation, compared to alloy systems like NiTi, CuZnAl or MnCu. But CuAlMn alloys have disadvantage due to generation of voids by a high shrinkage which further increases the existing proneness to stress cra
Mat. Res.. Publicado em: 19/07/2018
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6. Anelasticity of Phase Transitions and Magnetostriction in Fe-(27-28%)Ga Alloys
Several aspects of anelastic behavior of Fe-(27-28%)Ga-Tb alloys are considered in this paper: (i) the phase transitions from a metastable to an equilibrium phase and phase transitions between equilibrium phases at higher temperatures in as cast alloys, (ii) the nature of corresponding three transient anelastic effects, (iii) the formation of an intrinsic co
Mat. Res.. Publicado em: 07/06/2018
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7. Effect of the T6 Heat Treatment on Microhardness of a Directionally Solidified Aluminum-Based 319 Alloy
Aluminum alloys of the ANSI series 319 present Si and Cu as the main alloying elements and the mechanical strength of these alloys can be improved by the precipitation of the metastable Al2Cu phase during the ageing heat treatment. In this paper, the Al-5.5wt.%Si-3wt.%Cu alloy was elaborated and solidified in a water-cooled horizontal directional solidificat
Mat. Res.. Publicado em: 30/11/2017
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8. Mechanical Spectroscopy of Ti-15Zr-based Alloys with Mo Addition
In this paper, the effect of substitutional Mo amounts in internal friction and interstitial diffusion mechanisms was analyzed in Ti-15Zr-based alloys. Mechanical spectroscopy was obtained from room temperature up to 730 K with frequencies between 1 Hz and 40 Hz. Internal friction spectra were composed by anelastic relaxation peaks in β-type alloys (metasta
Mat. Res.. Publicado em: 27/11/2017
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9. Microstructure and Mechanical Properties of Ti-12Mo-8Nb Alloy Hot Swaged and Treated for Orthopedic Applications
Metastable β-type Ti alloys with non-toxic addition elements such as Mo, Zr, Sn, Ta and Nb were developed as an alternative to the widely used Ti-6Al-4V alloy for biomedical applications. These alloys possess enhanced biocompatibility and reduced elastic modulus in comparison with Ti-6Al-4V. Moreover, for orthopedic implants, low Young's modulus is required
Mat. Res.. Publicado em: 09/11/2017
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10. Fracture Modes of AISI Type 302 Stainless Steel Under Metastable Plastic Deformation
Martensitic transformation can be induced by plastic deformation in metastable iron-based alloys, such as stainless steels containing limited amounts of C, Ni and Cr. This transformation takes place at the temperature range from Ms and Md, usually at relatively lower temperature values. The transformed martensite has been associated with maximum ultimate str
Mat. Res.. Publicado em: 09/11/2017
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11. 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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12. Syntheses and Fundamental Properties of Cr/Mo-Adoped Fe-Rich Alloys With Metastable Phase and Saturation Magnetization Near 1.9 T
The Fe-rich alloys of Fe90-xSi5B5Mx (M= Cr or Mo; x=1, 2) are synthesized in the present study. The as-spun structure mainly consists of bcc phase plus a minor amount of metastable phase (Fe3B and/or Fe23B6). Comparing with the base alloy Fe90Si5B5, the corrosion resistance is improved significantly due to the formation of the passive film. Saturation magnet
Mat. Res.. Publicado em: 10/10/2016