Zirconia content

When water salts solutions are used in OPCM synthesis, provided the Me CA ratio is equal to 1 6 in all the composition range studied here (up to Zr relative content equal to 0.9), single phase samples with a cubic fluorite-like structure are formed. Thus, for ceria-zirconia samples with zirconia content up to 50 mol. %, ceria-based cubic solid solution is formed. For those samples, the lattice parameter is decreased as compared with that of a pure ceria phase, due to cerium cations substitution by zirconium cations with a smaller... 

For the xerogels (spectra b, c), the main Si-O-Si band moves toward lower wavenumbers as the zirconia content of sulfated mbted oxide increases. These spectral changes are consistent with a weakening of the silica network by zirconium atoms [5,12]. This shift to lower frequencies is sometimes attributed to the formation of Zr-O-Si bonds [5]. For the aerogels (spectra d, e), the Si-O-Si band shifts to lower frequencies when a small amount... 

Their resistance to aikaline media exceeds that of commercially available AR silicate glass fibers (Chapter 6) having a zirconia content of up to 15% [20]. Hydroxyl-free quaternary calcium aluminate glass fibers (Figure 9), e.g., non-silica fibers containing 46.2% AI2O3 -36.0% CaO - 4.0% MgO -13.8% BaO, afford sapphire-like infrared transmission properties. 

Fig. 5.47 Elastic modulus of composites as function of total zirconia content. The straight line predicted by the rule of mixtures is shown for comparison [31], With kind permission of Elsevier...

The critical stress-intensity factor, as a function of the total zirconia content, and relative toughness, as a function of the m-Zr02 content, when the t-Zr02 is excluded, are shown in Fig. 5.56. 

An additional mechanical property of interest in ZTA is its wear resistance. The wear transition load, namely the wear load at which a rapid increase in wear occurs, increases with increased zirconia content. The wear in ZTA depends on the... 

Alkali resistant (AR) glass fibres have been developed with a specific formulation that includes a substantial amount of zirconia (Z1O2). The higher the zirconia content, the better the resistance to alkali attack of the fibres. 

Table I shows physical and chemical properties of AZS products considered in this study for superstructure and glass contact applications (for example, breast walls, port arches, jambs, melter pavers, and fore hearth channels). It is clear that the bonded and vibro-cast refractories have lower bulk density, higher apparent porosity, lower thermal conductivity and lower thermal expansion, when compared with the fused-cast refractories. These differences exist despite similar chemistry, for example zirconia content in the range 25-34 weight %.

This and the fact that it perturbs the titania network crystallinity presumably decrease the photocatalytic activity even at lower zirconia content. 

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