Investigación de los mecanismos de corrosión a elevadas temperaturas de intermetálicos TiAl
[EN] TiAl intermetallics are materials with excellent specific properties and corrosion resistance, so they are materials of interest in the aircraft industry. The difficulty of processing of titanium and its alloys is in the high reactivity of the material; therefore, powder metallurgy is a interes...
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| Tipo de documento: | dissertação |
| Data de publicação: | 2013 |
| País: | España |
| Recursos: | Universitat Politècnica de València (UPV) |
| Repositório: | RiuNet. Repositorio Institucional de la Universitat Politécnica de Valéncia |
| Idioma: | espanhol |
| OAI Identifier: | oai:riunet.upv.es:10251/39939 |
| Acesso em linha: | https://riunet.upv.es/handle/10251/39939 |
| Access Level: | Acceso aberto |
| Palavra-chave: | Intermetalicos TiAl SPS Oxidación a elevadas temperaturas Microestructura Intermetallic TiAl Hight temperatura oxidation Microestructure CIENCIA DE LOS MATERIALES E INGENIERIA METALURGICA Máster Universitario en Ingeniería Mecánica y Materiales-Màster Universitari en Enginyeria Mecànica i Materials |
| Resumo: | [EN] TiAl intermetallics are materials with excellent specific properties and corrosion resistance, so they are materials of interest in the aircraft industry. The difficulty of processing of titanium and its alloys is in the high reactivity of the material; therefore, powder metallurgy is a interesting way of manufacturing for this material. Moreover, the material for the aircraft industry has very demanding requirements as porosity, is necessary the use of advanced powder metallurgy, since in the conventional technology one of the main drawbacks is the porosity inherent in the process. In advanced technologies should be noted the hot isostatic pressing (HIP) and especially in recent years, the spark plasma sintering (SPS). This process achieves a full densification with a short interaction time, maintaining the original grain size which represents a great advantage in the sintering of these materials. However, the application of intermetallic TiAl is mainly due to its high temperature resistance and in particular its lowest oxidation within the family of titanium alloys. In this paper we study the high-temperature oxidation of TiAl intermetallic obtained by SPS. Investigating the influence of process variables, temperature and time, in the formation of the microstructure as well as in the oxidation at elevated temperatures. Thus was obtained TiAl intermetallic alloys with addition of 2 %at of chromium and 2%at of niobium which is obtained a microstructure -TiAl + 2 (Ti3Al) whose distribution is primarily dependent on process temperature. The samples have been subjected to temperatures of 900°C for 200 minutes, using a thermogravimetry equipment in which it has been possible to track the increased weight along the dwell time. These tests have allowed obtaining different oxidation rates and thus defining various stages in the growth of crystals of oxidation. Rusted surfaces have been characterized morphologically by scanning electron microscopy, with which has been obtained the chemical composition of the oxides, and atomic force microscopy has allowed obtaining the surface roughness and threedimensional image. The phases were determined by X-ray diffraction and with Raman spectroscopy it has been shown the appearance preferential of rutile (TiO2) with a certain proportion of anatase. In any samples we have determined the formation of other oxides such as Al2O3 |
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