Hot Isostatic Pressing of Al2O3-ZrO2Composites

This paper reports the preliminary results of fabricating Al2O3-ZrO2composites by Hot Isostatic Pressing (HIPing). The idea was to produce toughened (by addition of ZrO2) and completely dense Al2O3—ZrO2 composites. 15 mol % of ultrafine unstabilized ZrO2 was milled with Al2O3. The as-mixed powder was cold isostatically pressed (CIPed), sintered at 1400°C for 1 hr and HIPed at 1450°C for 0.5 hr. The samples reached their theoretical density values. The results were compared to HIP diagrams described in the literature. It could be seen that in spite of some simplifying assumptions, theoretical predictions matched with the experimental results. Boundary diffusion was interpreted to be the dominant mechanism.