Abstract:

Objective  To find out how to prepare high-density dental ceramics through isostatic pressing so that sintering shrinkage will be reduced. Methods  To prepare Al2O3 /ZrO2 composite powder first, then to mold through dry-pressing, and to shape the green-body through isostatic pressing. The green-bodies were sintered at the tem- perature of 1 400 ℃ and kept at the temperature for different period of time（2 h, 3 h, 4 h）. After that, the
density and fracture strength were measured and the microstructure observed by scanning electron microscope（SEM）.  Results  The sample product′s density, line-shrinkage, and fracture strength of ceramics was rising with the sintering time lengthened. The sample product kept under the temperature of 1 400 ℃ for 4 hours, the fracture strength was（497.27±78.45） MPa and glass phase distributed evenly in the ceramics and the grains were integrated owing to the glass phase. The longer the sintering time, the more even the microstructure was. Conclusion  The sintering quality and the efficiency were improved through isostatic pressing.

Key words: dental materials, Al2O3 /ZrO2 composite ceramics, isostatic press technology