There are only three options for producing dense ceramics at an insufficiently high sintering temperature.

The first option: sintering of ultrafine (nano-sized) powders. Sintering ultrafine powders requires a lower temperature than sintering conventional micro-sized powders.

The second option is the use of sintering additives, for example, glass-forming additives.

Third option: pressure sintering.

Dear Sobron Yamin Lubis ;

Al2O3–ZrO2 nanocomposites can be synthesized by starting with the co-precipitation step of boehmite (AlO(OH)) and ZrO2, followed by microwave hydrothermal treatment at 270 °C and 60 MPa, and then by calcination at 600 °C. Using this method can obtain two nanocomposites: Al2O3–20 wt % ZrO2 and Al2O3–40 wt % ZrO2. The sintering temperatures of the nanocomposites are 1209 °C and 1231 °C, respectively—which is approximately 100 °C lower than reported for such composites. more details in the following references;

Article Mechanism of Reduced Sintering Temperature of Al2O3–ZrO2 Nan...

Article Effect of sintering temperature on density, hardness and too...

knowing the alumina phase you start with and the temperature limit of the furnace you can offer for sintering process may help to stand on the case study.

Best regards

Hi, Sobron Yamin Lubis

It depends on the composition you used, such as Zirconia Toughened Alumina (ZTA), etc. Also, you can lower the sintering temperatures of the Al2O3-ZrO2 composite by using the nanopowder from the same composite to get a high-density value.

My regards

Thanks