Synthesis and consolidation of (Zr0.94Y0.06)O1.88 nanopowders

In this study, a crystalline nanopowder of (Zr0.94Y0.06)O1.88 has been synthesized by means of combined method of coprecipitation and hydrothermal decomposition using (ZrО(NО3)2×1Н2О), (Y(CH3COO)3×1H2O), NH4OH as a precipitator, and hydroxyethylated nonylphenol as SAS. According to the dilatometry data optimal parameters of hot pressing have been determined. Powders were consolidated by means of the method of hot pressing with direct passage of current at 1100–1200 °С. The microstructures and properties of (Zr0.94Y0.06)O1.88 powder and ceramics were examined with the use of scanning and transmission electron microscopy, scanning probe microscopy, X-ray phase analysis, Vicker׳s hardness tester at a test load of 1 kg, and uni-axial compressive tests. It was found that as a result of compaction (Zr0.94Y0.06)O1.88 ceramics have uniform density distribution (grain sizes of 50–200 nm) with the following optimal mode consolidation values T=1200 °С and P=30 MPa. The fine-grain materials produced show high microhardness of 1408±30 HV1 and compressive strength of 2586 MPa.