Étude du comportement hygrothermique de matériaux céramiques réfractaires à liants alumineux pour le confinement de l'aluminium liquide

Abstract : This thesis aims to find solutions to minimize as much as possible the presence of micro-porosities in conventional and new aerospace alloys. These micro-porosities resulting especially from the reaction of the molten aluminum, during the casting phase, with the hydrogen provided by the steam contained in the refractory castables. Most of these castables are composites obtained with hydraulic binders based on aluminous cements. Firstly, a physico-chemical and mineralogical characterization of the basic materials and processed products was performed. Then, the thermo-hydric behavior of different castables and hardened cement pastes (principal source of the physical water and the chemical water) was then studied by moisture pick up tests made in various hygrothermal conditions, including at high temperatures (300 °C). It was shown that the hydric variations amplitudes strongly depend on the binder’s nature, in particular on its alumina content. The phenomena of physisorption and chemisorption are mobilized. Meanwhile, the transient thermal behavior in the time through the thickness of a refractory launder was modeled as a first step to quantify the water vapor transfer in the materials. Continuous measurements of temperature and pressure were obtained on pastes and concretes samples variously packged, placed in contact with a heated metal band maintained at 700 °C. Other measurements were made. They consisted into immersing samples (cement pastes and castables), previously stored in different hygrothermal conditions in liquid aluminum, in order to compare their reactivity in terms of release of hydrogen, oxygen and water vapor
Document type :
Theses
File URL :
.
Complete list of metadatas

https://hal.univ-lorraine.fr/tel-01751250
Contributor : Thèses Ul <>
Submitted on : Thursday, March 29, 2018 - 1:12:58 PM
Last modification on : Tuesday, August 21, 2018 - 9:46:04 AM

Identifiers

  • HAL Id : tel-01751250, version 1

Citation

Mohamed-Ali Maaroufi. Étude du comportement hygrothermique de matériaux céramiques réfractaires à liants alumineux pour le confinement de l'aluminium liquide. Autre. Université de Lorraine, 2014. Français. ⟨NNT : 2014LORR0235⟩. ⟨tel-01751250⟩

Share

Metrics

Record views

7