{"id":77765,"date":"2018-03-09T23:23:21","date_gmt":"2018-03-09T23:23:21","guid":{"rendered":"https:\/\/www.deberes.net\/tesis\/sin-categoria\/extrusion-en-caliente-de-polvo-de-aluminio-estudio-experimental-simulaca%c2%adon-por-elementos-finitos-y-aplicacion-a-otros-materiales\/"},"modified":"2018-03-09T23:23:21","modified_gmt":"2018-03-09T23:23:21","slug":"extrusion-en-caliente-de-polvo-de-aluminio-estudio-experimental-simulaca%c2%adon-por-elementos-finitos-y-aplicacion-a-otros-materiales","status":"publish","type":"post","link":"https:\/\/www.deberes.net\/tesis\/metalurgia\/extrusion-en-caliente-de-polvo-de-aluminio-estudio-experimental-simulaca%c2%adon-por-elementos-finitos-y-aplicacion-a-otros-materiales\/","title":{"rendered":"Extrusi\u00f3n en caliente de polvo de aluminio. estudio experimental, simulac\u00ed\u00f3n por elementos finitos y aplicaci\u00f3n a otros materiales"},"content":{"rendered":"<h2>Tesis doctoral de <strong> Mar\u00eda  Cristina Zubizarreta Zamacola <\/strong><\/h2>\n<p>Titulo: extrusi\u00f3n en caliente de polvo de aluminio.  Estudio experimental,  simulaci\u00f3n por elementos finitos y aplicaci\u00f3n a otros materiales resumen: en el presente trabajo se ha dise\u00f1ado y puesto a punto un utillaje para la extrusi\u00f3n directa en caliente de compactos de polvos, haciendo viable dicho proceso en una prensa hidr\u00e1ulica de compactaci\u00f3n. Se ha densificado un polvo de aluminio comercial pre aleado de la serie 2000 a trav\u00e9s de la extrusi\u00f3n directa en caliente. Las extrusiones se han realizado introduciendo cambios en las variables de procesamiento. Se han extruido compactos con distinta densidad y tambi\u00e9n se han aplicado tratamientos t\u00e9rmicos previos a la extrusi\u00f3n, modificando as\u00ed la cohesi\u00f3n entre part\u00edculas para una misma densidad en verde. Se ha estudiado el efecto de todos estos factores en la evoluci\u00f3n de la carga de extrusi\u00f3n a lo largo del proceso, as\u00ed como en la dureza, densidad y microestructura de los productos finales. Se han empleado las t\u00e9cnicas de difracci\u00f3n de rayos x, sem y ebsd para interpretar y entender los cambios microestructurales que se producen durante la extrusi\u00f3n. En todos los casos la extrusi\u00f3n conduce a un afino microestructural, produci\u00e9ndose adem\u00e1s la precipitaci\u00f3n de intermetalicos y distintos fen\u00f3menos de ablandamiento en funci\u00f3n del tratamiento t\u00e9rmico aplicado antes de la extrusi\u00f3n y la deformaci\u00f3n introducida en el proceso. Se han aplicado tratamientos de envejecimiento natural a los productos de extrusi\u00f3n para elevar su dureza y se ha analizado el efecto que dichos tratamientos tienen sobre la microestructura. Las simulaciones termomec\u00e1nicas empleando el c\u00f3digo de elementos finitos abaqus han permitido estudiar la distribuci\u00f3n de deformaciones, velocidades de deformaci\u00f3n, temperaturas y densidades en el material, as\u00ed como las tensiones sufridas por el utillaje y las cargas implicadas en el proceso, llegando a una buena correspondencia entre simulaci\u00f3n y realidad. Para ello ha sido necesario caracterizar mediante ensayos de compresi\u00f3n axisim\u00e9trica la fluencia de los materiales involucrados en el estudio, bajo diferentes combinaciones de temperatura y velocidad de deformaci\u00f3n. De esta manera, la combinaci\u00f3n si mulaci\u00f3n-resultados experimentales realizados con el aluminio ha permitido plantear la aplicaci\u00f3n de la extrusi\u00f3n a otros materiales como el acero r\u00e1pido, que por su mayor resistencia a la fluencia presenta dificultades de cara a ser conformado por exigir cargas de extrusi\u00f3n que superan las capacidades del equipo disponible y\/o la resistencia por parte del utillaje. Se ha visto que la coextrusi\u00f3n de acero r\u00e1pido con otro acero de menor resistencia es una soluci\u00f3n que permite la densificaci\u00f3n del acero r\u00e1pido por debajo de los l\u00edmites de carga e la prensa y con unas tensiones soportables para un nuevo dise\u00f1o de \u00fatillaje. in the present work a tooling has been designed and implemented in order to carry out the direct hot extrusion of powder compacts, allowing this process to occur in a hydraulic compacting press. A commercial aluminium powder has been densified by direct hot extrusion. Extrusions have been carried out changing the processing variables. Powder compacts with different green densities have been consolidated. The cohesion between partides has been modified by different heat treatments previous to extrusion. The evolution of the extrusion load with time during the process, the hardness, density and microstructure of the final products have been analysed for the different initial conditions. X- ray diffraction, sem and ebsd have been used to understand the microstructural changes taking place during extrusion. In all the cases the results show evidence of grain refinement, as well as inter-metallic precipitation and different softening phenomena depending on the heat treatment applied before extrusion and the strain involved in the processing. Natural aging after solution heat treatment has been applied to the extrusion products in order to increase their hardness and the effect of these treatments on the microstructure has been analysed. Thermomechanical simulations using abaqus software have allowed the study of the distribution of strains, strain rates, temperatures and densities in the material, the stresses suffered by the tooling and the loads needed for extrusion, obtaining a good agreetment between simulation and experiments. Axisymmetric compression tests at different temperatures and strain rates have been carried out to provide some input data for the thermomechanical modelling. In this way, the combination of simulation-experimental results carried out with aluminium has allowed for the eroposal of this application of extrusion to different materials such as the high speed steel , where high flow strength presents difficulties in order to be conformed due to limitations in the capacity of the press and the tooling strength. It has been seen that the co-extrusion of a high speed steel together with other steels of lower strength is a solution that allows the densification of the high speed steel below the load limits of the press and with stresses that the new tooling design can support.<\/p>\n<p>&nbsp;<\/p>\n<h3>Datos acad\u00e9micos de la tesis doctoral \u00ab<strong>Extrusi\u00f3n en caliente de polvo de aluminio. estudio experimental, simulac\u00ed\u00f3n por elementos finitos y aplicaci\u00f3n a otros materiales<\/strong>\u00ab<\/h3>\n<ul>\n<li><strong>T\u00edtulo de la tesis:<\/strong>\u00a0 Extrusi\u00f3n en caliente de polvo de aluminio. estudio experimental, simulac\u00ed\u00f3n por elementos finitos y aplicaci\u00f3n a otros materiales <\/li>\n<li><strong>Autor:<\/strong>\u00a0 Mar\u00eda  Cristina Zubizarreta Zamacola <\/li>\n<li><strong>Universidad:<\/strong>\u00a0 Navarra<\/li>\n<li><strong>Fecha de lectura de la tesis:<\/strong>\u00a0 14\/12\/2005<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n<h3>Direcci\u00f3n y tribunal<\/h3>\n<ul>\n<li><strong>Director de la tesis<\/strong>\n<ul>\n<li>I\u00f1igo Iturriza Zubillaga<\/li>\n<\/ul>\n<\/li>\n<li><strong>Tribunal<\/strong>\n<ul>\n<li>Presidente del tribunal: manuel Fuentes perez <\/li>\n<li>Alberto Etxeberria zubiria (vocal)<\/li>\n<li>angel Lopez echarri (vocal)<\/li>\n<li>anselmo Villellas malo (vocal)<\/li>\n<\/ul>\n<\/li>\n<\/ul>\n<p>&nbsp;<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Tesis doctoral de Mar\u00eda Cristina Zubizarreta Zamacola Titulo: extrusi\u00f3n en caliente de polvo de aluminio. Estudio experimental, simulaci\u00f3n por elementos [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-gradient":""}},"footnotes":""},"categories":[5453,7324,1586,17749,7060],"tags":[167353,13075,89440,38793,17940,167352],"class_list":["post-77765","post","type-post","status-publish","format-standard","hentry","category-aleaciones","category-metalografia","category-metalurgia","category-navarra","category-propiedades-mecanicas-de-los-solidos","tag-alberto-etxeberria-zubiria","tag-angel-lopez-echarri","tag-anselmo-villellas-malo","tag-inigo-iturriza-zubillaga","tag-manuel-fuentes-perez","tag-maria-cristina-zubizarreta-zamacola"],"_links":{"self":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/77765","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/comments?post=77765"}],"version-history":[{"count":0,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/posts\/77765\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/media?parent=77765"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/categories?post=77765"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.deberes.net\/tesis\/wp-json\/wp\/v2\/tags?post=77765"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}