Influence of gadolinia content in sinterability of components of alumina-gadolinia system

The alumina-gadolinia (Al2)3-Gd2 O3) system is of interest to the nuclear industry due to the absorption properties of gadolinia and to the inertness of alumina, chemically and neutronicly, as a ceramic matrix. In the powder processing, the spray dry method was used, at drying temperatures of about 350 deg C, because this method produces high homogeneity in the components. The compacting of the samples was done in a simple action with a flowing tool unidirectional press with 200 MPa. The sintering temperature and the gadolinia content were varied to analyse their influences in the process. The density, phases, porosity, and grain size of the samples were characterised. The experimental results revealed that only the Al2 O3 and Al Gd O3 phases were present. The gadolinium is a sintering inhibitor in this kind of material when 6,6% mol of Gd2 O3 is added. (author)