Microstructure and sintering kinetics of highly reactive ZrO2-Y2O3 ceramics

Microstructure characteristics of ultra-fine ZrO2Y2O3 ceramic powders

“…The (small) densification in the low pressure range can be ascribed to a rearrangement of the agglomerates. Below Pj the porosity and size of the agglomerates remain the same which means that no change in the internal agglomerate structure is expected [4,6]. Here, only the pores between the agglomerates disappear.…”

“…Here, only the pores between the agglomerates disappear. The agglomerate density as given in Table 1 is determined by measuring the pore volume of those pores which do not change in size and volume below Pj [6]. The linear relation between the logarithm of the compaction pressure vs. relative density indicates an identical compaction mechanism within the pressure range considered.…”

“…The hydrolysis was performed in a dispersion turbine as described in ref. 4. After hydrolysis, the gel was washed three times with water in order to remove organic solvents.…”

“…The gel was subsequently washed three times with ethanol for removal of the free water within the gel. All washing steps were performed with large amounts of washing agent (gel concentration of about 0.1 M) using a high-energy disc turbine [4].…”

“…Those very fine-grained powders are very difficult to obtain as a really monodispersed powder. They consist of preferably loosely bound aggregates and/or agglomerates [1][2][3][4][5][6]. These crystallite "clusters" determine for example the powder flow, packing and sintering behaviour of the material [1,2].…”