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Author Ramanathan, S. ♦ Kumar, K. P. Krishna ♦ De, P. K. ♦ Banerjee, S.
Source CiteSeerX
Content type Text
File Format PDF
Subject Domain (in DDC) Computer science, information & general works ♦ Data processing & computer science
Subject Keyword Dispersion Condition ♦ Solid Concentration ♦ Solid Content ♦ Calcination Temperature ♦ Little Change ♦ Aqueous Suspen-sions ♦ Dry Ground ♦ Cal-cined Powder ♦ Sub-micron Size ♦ Mean Particle Size ♦ Viscosity Study ♦ Tg Dta ♦ Dispersion Stability ♦ Substantial Amount ♦ Pseudo-plastic Flow Characteristic ♦ Sinter-active Powder ♦ Dry Ground Powder ♦ Coarse Agglomerate ♦ Electrostatic Columbic Repulsion Mechanism ♦ Particle Size ♦ Maximum Numerical Value ♦ Ideal Ph ♦ Theoretical Density ♦ Ground Slurry ♦ Size Range ♦ Xrd Study ♦ Wet Grinding ♦ Mole Yttria ♦ Zeta-potential Variation
Abstract Abstract. A precursor for zirconia – 8 mole % yttria (YSZ – rO2–8 m % Y2O3) powder was prepared by co-precipitation and the calcination temperature was fixed as 900°C from TG–DTA and XRD studies. The cal-cined powder could be dry ground only to a mean particle size (D50) of 6 mm containing substantial amount of coarse agglomerates in the size range 10–100mm. The dispersion conditions for its wet grinding were evalu-ated through zeta-potential and viscosity studies. The zeta-potential variation with pH of the aqueous suspen-sions of the powder exhibited maximum numerical values at 3 and 11pH, exhibiting the ideal pHs for dispersion stability through electrostatic columbic repulsion mechanism. Slurries of dry ground powders with solid concentration in the range 15–30 vol. % exhibited pseudo-plastic flow characteristics, indicating presence of flocculates. With progress of grinding, the increase in viscosity of the slurries b came less significant with decreasing solid concentration. Even though the particle size of the ground slurries decreased with decreasing solid content, there was little change in it for slurries with solid content < 20 vol.%. Grinding conditions for formation of sinter-active powders of YSZ with sub-micron size (D50 ~ 0×7 mm free of agglomerates of size> 5 mm) were established. Compacts from this powder could be sintered at 1400°C to translucent bodies with 99 % theoretical density.
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Research
Education Level UG and PG ♦ Career/Technical Study
Learning Resource Type Article
Publisher Date 2004-01-01