1989 Volume 97 Issue 1129 Pages 941-946
Fine powders of partially stabilized zirconia containing 2mol% Y2O3 were synthesized from water-alcohol solutions of ZrO(NO3)2⋅2H2O and YCl3⋅6H2O with various concentrations, [Zr4++Y3+]=0.25-0.9mol/l, by the spray pyrolysis technique using a 2-fluids nozzle. The powders obtained were calcined between 1100° and 1300°C and milled for 12h. The powders so obtained were characterized by crystallite size and specific surface area measurements, TEM and SEM observations. On the basis of these results, the influence of powder properties such as primary particle size, degree of agglomeration, and green density on the density of the ceramic bodies (Y-TZP) fabricated by pressureless sintering at 1300° to 1500°C was investigated. The green density increased with an increase in calcining temperature, but was slightly affected by the concentration of solutions. With decreasing calcining temperature and/or decreasing concentration of solution, the size and degree of aggregation of primary particles decreased. Sintered bodies with 98% T. D. was obtained from the powders prepared in the present method by firing at 1300°C. The sinterability of the powders at 1400°C was almost independent of the concentration of solution, and 98% T. D. was obtained from the powder prepared from a concentrated solution of 0.9mol/l.
