Assessment on mechanical properties controlling of alumina ceramics for harsh service conditions

Abstract Improvement of mechanical properties of alumina ceramics is investigated by addition of MgO and ZrO 2 starting from inorganic precursors. The doping of alumina ceramics is performed by infiltration of solutions of magnesium chloride and zirconium oxychloride into preformed samples. Two types of alumina powders were used. The impregnated samples were fired in 1550–1780 °C temperature range and characterised by bulk density, bending strengths and their microstructure are analysed. The dispersion and concentration of reinforcing particles is analysed by electron microprobe (energy dispersive analysis). After firing the infiltration method leads the dopants concentrate especially at the surface of samples. The surface enrichment in dopants determines increased strengths with about 17–27% as function of sintering temperature.