119 research outputs found

    Fabricación de aleaciones ligeras de Titanio y Aluminio por metalurgia de polvos

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    La UC3M desarrolla aleaciones ligeras de Titanio y Aluminio mediante técnicas pulvimetalúrgicas permitiendo adaptar las composiciones y propiedades a aplicaciones específicas. Sectores como la automoción requieren el empleo de materiales con propiedades mejoradas que aúnen resistencia mecánica, buen comportamiento al desgaste y corrosión disminuyendo el peso de los componentes fabricados a partir de los metales tradicionalmente empleados. Para su implantación es clave la colaboración de empresa

    Manufacturing of Titanium and Aluminium Light alloys by powder metallurgy

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    The Group of Powder Technology (GTP) of the University Carlos III has a wide experience in the development and processing of new materials by Powder Metallurgy (PM). The mechanical alloying (MA) process, or high energy milling, allows the attainment of powders with compositions impossible to produce by other techniques, with improved properties for structural applications, where mechanical properties are the main requirement, and for applications where other specific properties are needed. The identification of the specific needs of interested industrial sectors is a critical point in this development

    Development of new materials by high energy milling

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    The Group of Powder Technology (GTP) of the University Carlos III has a wide experience in the development and processing of new materials by Powder Metallurgy (PM). The mechanical alloying (MA) process, or high energy milling, allows the attainment of powders with compositions impossible to produce by other techniques, with improved properties for structural applications, where mechanical properties are the main requirement, and for applications where other specific properties are needed. The identification of the specific needs of interested industrial sectors is a critical point in this developmen

    Study of the properties of low-cost powder metallurgy titanium alloys by 430 stainless steel addition

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    Titanium is a lightweight metal with an outstanding combination of properties which make it the material of choice for many different applications. Nonetheless, its employment at industrial level is not widespread due to higher production costs with respect to competitor metals like steel and aluminium. In this work the production of low-cost titanium alloys is attempted by combining the utilisation of a powder metallurgy process and cheap alloying elements (i.e. commercial 430 stainless steel powder optimised for the powder metallurgy industry). Low-cost titanium alloys are fabricated by blending elemental titanium with stainless steel. The behaviour of the powders as well as that of the sintered materials are analysed and compared to that of a master alloy addition Ti6Al4V alloy. The produced low-cost titanium alloys show comparable properties to both wrought and powder metallurgy titanium alloys and, therefore, they are proposed as an alternative to obtain structural component made out of titanium alloys.The authors want to acknowledge the financial support from the Spanish Ministry of Science through the R&D Projects MAT2012-38650-C02-01, and from Regional Government of Madrid through the ESTRUMAT (S2009/MAT-1585) projec

    Low-Cost α+β PM Ti Alloys by Fe/Ni Addition to Pure Ti

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    Ti and its alloys can deliver a very interesting combination of properties such as low density, high strength, corrosion resistance and biocompatibility and, therefore, are very flexible materials which can be adapted to various applications. Nonetheless, Ti and Ti alloys are only employed in critical applications (i.e. aeronautical and aerospace, nautical, medical, etc.) or in products for leisure. In both of these cases the higher fabrication costs of Ti in comparison to its competitors (i.e. steel and aluminium) is not the limiting factor as it is for many structural applications, especially for mass production (i.e. automotive sector). The use of creative techniques and the decrement of the starting price of Ti have been identified as the two main routes to follow to decrease the fabrication costs. In this study, the production of low-cost α+β Ti alloys has been assessed by combining the addition of cheap alloying elements (in particular a Fe/Ni powder) with the classical powder metallurgy route (pressing and sintering). Physical and mechanical properties as well as microstructural analysis of these low-cost alloys were measured and correlated to the processing parameters used to sinter them. It is found that the low-cost Ti alloys show similar behaviour to conventional α+β Ti alloys and, thus, have the potential to be used for non-critical applications

    Discover, Reuse and Share Knowledge on Service Oriented Architectures

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    Current Semantic Web frameworks provide a complete infrastructure to manage ontologies schemes easing information retrieval with inference support. Ideally, the use of their frameworks should be transparent and decoupled, avoiding direct dependencies either on the application logic or on the ontology language. Besides there are different logic models used by ontology languages (OWL- Description Logic, OpenCyc-FOL, ...) and query languages (RDQL, SPARQL, OWLQL, nRQL, etc..). These facts show integration and interoperability tasks between ontologies and applications are tedious on currently systems. This research provides a general ESB service engine design based on JBI that enables ontology query and reasoning capabilities thought an Enterprise Service Bus. An early prototype that shows how works our research ideas has been developed

    Long-term atmospheric fluxes of radionuclides at a coastal Mediterranean station

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    7Be is one of the radionuclide produced by spallation reactions of cosmic rays with light atmospheric nuclei. 7Be rapidly associates primarily with submicron-sized aerosol particles. Gravitational settling and precipitation processes largely accomplish transfer to the earth’s surface. 210Pb which is one of the natural radionuclide of the 238U series is widely used as a tracer. 210Pb depositional pattern gave us information on continental aerosols in lower troposphere. These two radionuclides with their different sources and therefore are useful to understand the mechanisms of aerosol removal from the atmosphere. These radionuclides have measured routinely in many places in order to study the description of environmental processes such as aerosol transit and residence times in the troposphere , aerosol deposition velocities and aerosol trapping by ground vegetation.40K has been associated with the arrival of coarse re-suspended material from the Africa continent. The bulk atmospheric deposition of 7Be , 210Pb and 40K has been measured at Málaga , south-eastern Spain, from January 2005 to December 2012 for monthly periods.CS

    Analyses of long-term measurements (2005-2012) of 7Be concentrations in surface air aerosols

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    Studies of radionuclide activities in aerosol particles provide a mean for evaluating the integrated effects of transport and meteorology on the atmospheric loadings of substances with different sources. The aim of the present study is to explain the behaviour of aerosols associated with 7Be (T1/2=53.3 days) in the surface atmosphere using exploratory data analysis to obtain information on their possible mechanisms of transport and deposition. This naturally occurring radionuclide is an important isotope in studying atmospheric processes because of its convenient half-life and sufficiently detectable -radiation (E = 0.477 MeV), which has served for studying precipitation scavenging, vertical and horizontal removal of air masses, aerosol transit and residence times in the troposphere [1]

    Variations of PM10 and its relationship with 7Be and 210Pb measurements at Malaga (Southeastern coast of Spain)

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    INTRODUCTION Levels of particulate matter fraction PM10 were monitored between 2009 and 2011 in Malaga (Spain) in one of the Atmospheric Pollution Monitoring network managed by the Environmental Health Service of the Andalusian Government. Long-term measurements of cosmogenic radionuclides such as 7Be provide important data in studying global atmospheric processes and comparing environmental impact of radioactivity from man-made sources to natural ones. 7Be is a natural radionuclide tracer of aerosols originated over a range of high altitudes in the atmosphere. On the other hand, 210Pb is produced by radioactive decay from its progenitor, 222Rn, which emanates primarily from land surface. Therefore, 210Pb in the air is an effective tracer of the continental surface air mass. The variation of the data with time was studied by time series analyses and seasonal patterns were identified. The study of air back-trajectories were computed by means of the Hybrid Single-Particle Lagrangian Integrated Trajectories (HYSPLIT) trajectory model (Draxler, 1994) using meteorological data supplied by the US National Climatic Data Centr

    Atmospheric fluxes of radionuclides on monthly time-scale in Málaga (Spain)

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    ABSTRACT.- Bulk atmospheric deposition of gamma radionuclides ( 7Be, 210Pb and 40K ) has been measured at Málaga (4º 28´80′′ W; 36º 43′ 40′N) at a coastal Mediterranean station in the south of Spain, from January 2005 through December 2012 for monthly period
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