Synthesis and electrical field-assisted sintering behaviour of yttria-stabilized tetragonal ZrO2 nanopowders by polyacrylamide gel method

Abstract

The tetragonal ZrO 2 nanopowders stabilized with 3 mol% Y 2 O 3 (3YSZ) were synthesized using a polyacrylamide gel method. The mean particle size of the 3YSZ nanopowders was found to decrease with increasing molecular ratio of monomer to the precursor salt. The 3YSZ nanopowders with mean particle size of 12 nm can be densified in 1 h at 800 • C, by the application of a d.c. electrical field. Under a constant d.c. electrical field, the current density through the specimen of 3YSZ rose rapidly when the temperature increased to a certain value. In the sintering process, the current density was restricted when the sharp increase occurred. By limiting current density to different values for one hour, it was found that current density was the most important factor in electrical fieldassisted sintering process. The grain size of 3YSZ bulk increased with the enhanced current density. The stable stage of electrical field-assisted sintering process can be explained by Joule heating. Corresponding real temperature of specimens is estimated by applying black body radiation theory.

Flash sintering of 3YSZ/Al2O3‐platelet composites

“…3YSZ powders were prepared using a polymer network gel method. 27 In a typical preparation, zirconium oxychloride (ZrOCl 2 ·8H 2 O), and yttrium nitrate (Y(NO 3 ) 3 ·6H 2 O) were dissolved in deionized water. The concentration of Zr 4+ and Y 3+ was 0.04 and 0.0024 mol/L, respectively.…”