| Refractories used in the aluminum industry have to face hard environment conditions. In holding and melting furnaces, major problems come from the corrosion of the refractories by molten aluminum and from the oxidation of the molten metal. The presence of alloying elements inside the molten metal plays a role on the corrosion resistance of refractories, as well as the addition of fluxes. These fluxes are molten salts, chloride or fluoride-based, added on the surface of the molten alloy. They may have different functions such as preventing the metal from oxidation, reducing the metal content of the skim or removing inclusions or impurities from the metal. But these salts do not remain without any effect on the corrosion of the refractory materials.; Refractory materials concerned in this work are all aluminosilicate refractories with various compositions (SiO2/Al2O3 = 0,14--1,12). Different kinds of experiments are performed to evaluate their resistance in contact with molten aluminum. Corrosion tests like the standard full immersion test are used to appreciate the effects of alloying elements; they imply aluminum alloys such as Al-5%poids Mg, Al-13%poids Si, Al-5,5%poids Zn and the 7075 alloy (5,5%poids Zn, 2,5%poids Mg, 1,6%poids Cu). (Abstract shortened by UMI.)... |
