Complementary analysis techniques applied on optimizing suspensions of yttria stabilized zirconia

Abstract

Three different polymers with different functional groups and similar molecular weight were tested as dispersing agents for suspensions of yttria stabilized zirconia in ethanol: polyvinyl pyrrolidone, polyethylene imine, polyvinyl butyral/acetale. The stability of the system was assessed considering, in details, all the processing steps, including suspension de-agglomeration, slurry manipulation, quality of sintered tapes microstructure, and final layer leak tightness. Different analytical techniques were used to monitor ceramic deagglomeration and stability as a function of time, for different types of dispersing agent and to optimize the dispersants concentration: Electrokinetic Sonic Amplitude was used to obtain zeta potential, Multiple Light Scattering for evaluating sedimentation rate, and multi-wavelength laser light scattering for measuring particle size distribution. All the

Citrate- and glycerol triesters as novel dual-functional dispersants and plasticisers for ceramic processing

“…When sintering at temperatures in excess of 1250 C for up to 12 h, almost completely dense and crack free ceramic specimens can be obtained as demonstrated in Figure 10. The remaining porosity is comparable to that obtained with more traditional dispersants such as PVP or PEI (37). The grain sizes are, however, larger ranging from ≈ 0.5 to ≈ 2 µm.…”

Dispersants for silicon carbide in water—A comparative study

“…Sedimentation studies were performed with a Turbiscan Lab (Formulaction, France) using the Turbisoft software version 2.1.0.52. Essentially the setup follows the position of the sedimentation front as a function of time with high precision and this can be used to evaluate the overall stability of a suspension as described elsewhere 29 …”

“…Zeta‐potentials were determined measuring the Electrokinetic Sonic Amplitude (ESA) with the instrument ZetaProbe Analyzer (Colloidal Dynamic LLC, USA). The measurement can be used to assess the extent of electrostatic stabilization as described elsewhere 29 …”

“…The dispersing properties were investigated by measuring zeta‐potential as a function of pH as well as sedimentation properties and PSDs at selected conditions. This combination has previously been used to distinguish between dispersants acting by a steric and/or electrostatic mechanism as well as to evaluate the long‐term stability of a suspension and the ability of a dispersant to break down agglomerates into primary particles 29 . All the experiments have been conducted with slurries having SiC solid load relevant for dip/coating applications.…”

The effects of sintering additives on the ceramic matrix composite of ZrO2: microstructure, densification, and mechanical properties – a review

“…Hence, in the YSZ, as the movement of the proton increases, there is a decrease in the loss of energy as a consequence of depression of the ohmic resistance on the solidified electrolyte [44,45]. Also, the addition of yttria improves chemical stability and mechanical properties in a distinctive functional environment, this accomplishes the necessity of the electrochemical structure besides elevated performance for a YSZ [46,47]. The aforementioned features of Yttria-stabilised zirconia have brought its prominent use in comparison to other stabilised zirconia materials.…”