The effect of zirconia content on properties of Al2O3–ZrO2 (Y2O3) composite nanopowders synthesized by aqueous sol–gel method

Al2O3–ZrO2 (Y2O3) nanopowders containing 5, 10 and 15 wt% ZrO2 were synthesized by aqueous sol–gel method using aluminum sec-butoxide and zirconium butoxide as precursors. BET analysis shows that, increasing the zirconia content results in a decrease in surface area, 152, 125 and 121 m2/g, and an increase in pore size, 5.63, 9.79 and 11.05 nm for 5, 10 and 15 wt% ZrO2, respectively. Furthermore, a shift toward higher temperatures is observed for transition of transitional aluminas to stable α-alumina phase through increasing the zirconia content. SEM micrograph of calcined nanopowders revealed nanosize spherical particles in the range of 15–75 nm.