Esta tesis se basa en el reciclaje de los metales, se estudian los métodos de fabricación empleados para la creación de algunos de éstos, sobre todo del aluminio. En el que más se centra esta tesis es en la pulvimetalurgia, que consiste en la creación de metales a partir de polvos aleados mecánicamente.|
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April 16, 2015 (v1)PublicationUploaded on: March 27, 2023
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January 14, 2015 (v1)Publication
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Uploaded on: March 27, 2023 -
May 4, 2022 (v1)Publication
Se ha fabricado polvo amorfo de la aleación Al75Fe25 a partir del polvo elemental cristalino de aluminio puro y hierro puro. El proceso de fabricación del polvo amorfo se ha llevado a cabo mediante molienda mecánica con una duración de hasta 100 horas. El objetivo de este trabajo consiste en determinar la evolución de la compresibilidad y de la...
Uploaded on: March 25, 2023 -
July 21, 2020 (v1)Publication
The crystallization process, both at the initial and subsequent stages, of amorphous Al88-RE4-Ni8 alloys (RE = Y, Sm and Ce) has been studied. Additionally, the consequences of adding 1 at.% Cu replacing Ni or Al were studied. The stability of the amorphous structure in melt spun ribbons was thermally studied by di erential scanning...
Uploaded on: December 4, 2022 -
January 26, 2022 (v1)Publication
This research focused on studying the effect of temperature on the mechanical properties of aluminium matrix composites (AMCs) obtained by a powder metallurgy route. Aluminium powder was milled at room temperature for 5 h and using di erent atmospheres in order to achieve di erent amounts of reinforcement. The atmospheres employed were vacuum,...
Uploaded on: March 27, 2023 -
January 14, 2015 (v1)Publication
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Uploaded on: March 26, 2023 -
January 14, 2015 (v1)Publication
Polvos mezclados de aluminio y titanio ( 10 % en peso) han sido aleados mecánicamente en un molino Attritor, obteniéndose una solución metaestable de titanio en la matriz de aluminio. Se han estudiado los cambios producidos en la forma y tamaño de las partículas, estructura y microestructura, al variar el tiempo de molienda entre 2 y 10 h. El...
Uploaded on: December 4, 2022 -
January 29, 2018 (v1)Publication
La fabricación de núcleos amorfos (tanto para motores eléctricos, como transformadores) es una tarea compleja que hasta ahora ha requerido la fabricación del material amorfo en forma de cintas de fino espesor (mediante enfriamiento muy severo, melt spinning) y su posterior apilado y/o plegado para la formación de la pieza final. El proceso...
Uploaded on: March 27, 2023 -
June 21, 2021 (v1)Publication
Porosity is a characteristic present in most sintered materials, full densification only being achieved in special cases. For some sintered materials, porosity is indeed a desired characteristic, serving for the intended application of the material. In any case, the porosity present in materials can have a strong effect on some of their...
Uploaded on: March 25, 2023 -
March 23, 2021 (v1)Publication
Aluminium powder was mechanically alloyed under ammonia gas flow for different times (1-5 h) in order to produce a second-phase reinforcement, mainly by aluminium nitride (AlN). After milling, powders were consolidated by cold uniaxial pressing and vacuum sintering. A small amount of copper powder was added to the Al milled powder to improve...
Uploaded on: December 4, 2022 -
October 5, 2016 (v1)Publication
Properties of compacts made from aluminium powder, milled under different atmospheres, were evaluated. The duration of all the milling processes was 10 h, although different atmospheres were tested: vacuum, confined ammonia, and vacuum combined with a short-time ammonia gas flow (5 min). Milled powders were consolidated by cold uniaxial...
Uploaded on: December 4, 2022 -
June 24, 2021 (v1)Publication
Manufacturing metallic materials from elemental or alloyed powders is an option in many industrial processes. Nevertheless, the traditional powder metallurgy processing including furnace sintering is at times detrimental for the microstructure attained in the powders. Alternative sintering processes based on the use of electricity and the...
Uploaded on: March 25, 2023 -
July 8, 2020 (v1)PublicationInfluence of processing parameters on the conduct of electrical resistance sintering of iron powders
The influence of the applied pressure and electrical parameters on the macrostructure of specimens consolidated by the medium-frequency electrical resistance sintering technique (MF-ERS) is analysed in this work. This technique is based on the application of pressure to a mass of conductive powder that, simultaneously, is being crossed by a...
Uploaded on: December 4, 2022 -
February 3, 2022 (v1)Publication
The fabrication of soft magnetic Fe parts by the medium-frequency electrical resistance sintering (MF-ERS) technique is studied in this paper. This consolidation technique involves the simultaneous application to metallic powders of pressure and heat, the latter coming from the Joule effect of a low-voltage and high-intensity electric current....
Uploaded on: December 2, 2022 -
December 18, 2016 (v1)Publication
El Grupo de Metalurgia e Ingeniería de los Materiales de la Universidad de Sevilla ha desarrollado, durante los últimos quince años, diversas técnicas para la consolidación de aleaciones de aluminio obtenidas por aleado mecánico (AM) de polvos. Las aleaciones, reforzadas por segundas fases precipitadas durante el procesado, han sido prensadas y...
Uploaded on: March 27, 2023 -
May 25, 2023 (v1)Publication
Commercially pure iron powder has been processed by the capacitor electrical discharge consolidation technique. This consolidation technique applies an external pressure and, at the same time, heats a metallic powder mass by the Joule effect of a high-voltage and high-intensity electric current. In this work, a capacitor charged at low voltage...
Uploaded on: May 26, 2023 -
April 11, 2017 (v1)Publication
The production of high hardness and thermally stable nanocrystalline aluminium composites is described. Al powder was milled at room temperature in an ammonia flow for a period of less than 5 h. NH3 dissociation during milling provokes the absorption, at a high rate, of nitrogen into aluminium, hardening it by forming a solid solution....
Uploaded on: March 27, 2023 -
December 16, 2019 (v1)Publication
A novel processing method for amorphous Al50Ti50 alloy, obtained by mechanical alloying and subsequently consolidated by electrical resistance sintering, has been investigated. The characterisation of the powders and the confirmation of the presence of amorphous phase have been carried out by laser diffraction, scanning electron microscopy,...
Uploaded on: December 4, 2022 -
February 25, 2020 (v1)Publication
The unique combination of hardness, toughness and wear resistance exhibited by WC-Co cemented carbides (hardmetals) has made them a preeminent material choice for extremely demanding applications, such as metal cutting/forming tools or mining bits, in which improved and consistent performance together with high reliability are required. The...
Uploaded on: December 4, 2022 -
December 1, 2023 (v1)Publication
Molienda mecánica de polvos activada por radiación ultravioleta. La presente invención tiene por objeto la molienda mecánica de polvos activada por radiación ultravioleta, lo que permite la mejora de las características de materiales en forma de polvo. Concretamente, la realización de moliendas en presencia de radiación ultravioleta (UV)...
Uploaded on: December 3, 2023 -
February 21, 2018 (v1)Publication
In this paper, a phenomenological model to predict the value of the electrical resistance of a compressed metal powder mass is proposed. The model, based on the experimental compressibility and resistivity-porosity curves, is useful in the field of the electrical resistance consolidation. In this area is often required to find out whether a...
Uploaded on: March 27, 2023