Nb Alloys
Mostrando 1-12 de 96 artigos, teses e dissertações.
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1. Effect of Welding Parameters on Nanostructured Fe-(C, B)-(Cr, Nb) Alloys
New nanostructured Fe-(Nb,Cr)-(C,B) multicomponent alloys have been developed for hardfacing application. They have better wear resistance than traditional Fe-Cr-C alloys. The nano-alpha-Fe, eutectic and hard carboborides phases of the weld metal usually show variations with the welding procedure. 6 test samples with different heat input were welded. It was
Mat. Res.. Publicado em: 20/01/2020
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2. Microstructure and Thermal Analyses of Cu87-xAl13Nbx High-Temperature Shape Memory Alloys
This paper presents a thermal and microstructural characterization of Cu87-xAl13Nbx (wt%) high temperature shape memory alloys (HTSMA), with Nb contents ranging from 1 to 3%. The alloys were obtained by arc melting under argon atmosphere. Thermal characterization was performed by differential scanning calorimetry (DSC), revealing that the phase martensitic t
Mat. Res.. Publicado em: 28/11/2019
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3. Nb-Al Binary System: Reevaluation of the Solubility Limits of the (Nb), Nb3Al, Nb2Al and NbAl3 Phases at High Temperatures
In this work a re-investigation of the solubility limits of the (Nb), Nb3Al, Nb2Al and the Nb-rich side of the NbAl3 phases on the Nb-Al system is presented. Alloys in the binary fields ((Nb)+Nb3Al, Nb3Al+Nb2Al and Nb2Al+NbAl3) were arc-melted, and then equilibrated at 1000, 1200 and 1400 ºC. The phases were confirmed via X-ray powder diffractometry, and th
Mat. Res.. Publicado em: 25/11/2019
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4. Characterization of Ti-35Nb alloy surface modified by controlled chemical oxidation for surgical implant applications
ABSTRACT Titanium-Niobium alloys have been studied for biomedical applications due to their satisfactory biocompatibility. In order to improve the long-term implantation, surface modification techniques have been developed to generate suitable topography, roughness, chemical composition, surface energy, etc. Considering this approach, the present work aimed
Matéria (Rio J.). Publicado em: 16/09/2019
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5. Influence of Directional Solidification on the Mechanical Properties of Cu-Al-Be-Nb-Ni Alloy
Copper-based polycrystalline shape memory alloys (SMAs) have limitations for many practical applications due to their low superelasticity and low ductility. In order to overcome this situation, in recent years, the production of copper-based SMAs by directional solidification process has attracted the interest of many researches. In this sense, the present w
Mat. Res.. Publicado em: 05/09/2019
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6. Influence of Mechanical Cycling on Residual Strain in Superelastic Cu-Al-Be-Nb Alloys
The understanding of the stabilization mechanism of martensite used to obtain alloys with high hysteresis and the possibility of recovering this martensite (residual strain) by heating at temperatures higher than As and Af have been fundamental for application in bonding devices. One of the possibilities to enhance residual strain is through mechanical cycli
Mat. Res.. Publicado em: 15/07/2019
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7. Influência da microestrutura na resistência ao desgaste microabrasivo de ligas de F-Cr-C e Fe-Cr-C-Nb
ABSTRACT Neste trabalho é feita uma avaliação da influência do teor de cromo e da combinação do cromo e nióbio em ligas de revestimento duro do tipo Fe-Cr-C, na microestrutura e propriedades que envolvam a resistência ao desgaste microabrasivo. Vários estudos têm sido realizados em busca de informações conclusivas sobre este sistema em condiçõe
Matéria (Rio J.). Publicado em: 20/05/2019
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8. Crystallization Behavior and Mechanical Properties of Cu-based Bulk Metallic Glass Composites
This work highlights the relationship between the preparation, crystallization behavior, microstructures, and mechanical properties of Cu-based bulk metallic glasses (BMGs) and their composites (BMGCs). (Cu47Zr45Al8)97.5Y1.5Nb in-situ BMGCs were prepared using isothermal annealing, and the experimental results indicate tunable mechanical properties of the al
Mat. Res.. Publicado em: 06/05/2019
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9. Effect of Solid Solution + Double Ageing on Microstructure and Properties in the Layer by Layer of the Z-Y Interface of Inconel 718 alloys Fabricated by SLM
The microstructure in the Z-Y surface of Inconel 718 alloys fabricated by selective laser melting (SLM) shows the relatively homogeneous and irregular fine grain structure after the heat treatment process of 1050ºC solid solution + double ageing. A large number of bulk precipitates were observed on the grain boundary, and the typical dendritic crystallizati
Mat. Res.. Publicado em: 11/10/2018
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10. Influence of Small Content Elements Additions on the Glass Forming Ability of Zr-based Bulk Metallic Glasses Alloys
The present work reports investigation on the Glass Forming Ability (GFA) of Zr-based Bulk Metallic Glasses (BMG’s) by microalloying with early transition metals. GFA was measured as the amorphous fraction formed in samples with different diameters using optical microscopy (OM) and image analysis techniques. Samples with the highest GFA had their oxygen co
Mat. Res.. Publicado em: 06/09/2018
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11. 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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12. Efecto de la sustitución de V por Ti sobre las temperaturas de transformación de fase y el desajuste de red matriz/precipitado en la superaleación 76Fe-12Al-12V
ABSTRACT Fe-Al based alloys have a remarkable potential for high temperature structural applications, provided that the limitation of their low creep resistance is solved. Third element addition (Nb, Ti, Zr or Ta) has proven to per-form the task, at the expense of a low ductility. In previous works we have investigated ferritic alloys in the Fe-Al-V system w
Matéria (Rio J.). Publicado em: 19/07/2018