Ceramics based on zirconium dioxide stabilized with yttrium concentrate

Conclusions Zirconium dioxide with an addition of 15% by weight of yttrium concentrate when fired at 1550°C, and held for 5 h, forms a solid solution of the fluorite cubic modification type. This solid solution does not decompose when held for long periods in the range 1100–1400°C, possesses excellent resistance at temperatures of about 2100°C, and in this regard is equivalent to zirconia-yttrium solid solution.The materials based on zirconia stabilized with yttrium concentrate have somewhat higher specific electric conductivities than zirconium-yttrium solid solutions.Translated from Ogneupory, No. 6, pp. 45–48, June, 1971.     

Electric discharge sintering of ceramics based on zirconium dioxide

The possibility of sintering zirconium ceramics in the plasma of a glow discharge is investigated. It is shown that sintering in ammonia plasma substantially improves the physicomechanical characteristics of sintered materials as compared to sintering in air plasma and in vacuum heat-treating furnaces. The improvement of the properties is mainly due to the additional stabilization of high-temperature ZrO₂ phases by nitrogen and is also explained by specific sintering conditions in the electric field of the glow discharge.Translated from Ogneupory, No. 9, pp. 20 – 22, September, 1994.     

Vacuum sintering of a ceramic based on zirconium dioxide

The results of a study of the phase composition and mechanical properties of a ceramic based on ZrO₂-Y2O₃ after vacuum sintering of powders with complex morphology in a wide range of temperatures and sintering holding times are reported. Dense ceramic materials with high mechanical properties were obtained.Translated from Steklo i Keramika, Nos. 5–6, pp. 27–29, May–June, 1994.     

High-strength ceramic based on zirconium dioxide: preparation and properties

Strength properties are considered for ZrO₂ hot-pressed ceramic materials stabilized with 4 – 6 wt.% Y₂O₃ in relation to original powder preparation method: solid phase synthesis, high-temperature salt thermolysis, combined hydroxide precipitation followed by freezing, drying and calcining, and the sol-gel method. Ceramic material with the highest strength in bending (up to 1350 MPa) are prepared from ZrO₂ – 5 wt.% Y₂O₃ powders, synthesized by coprecipitation of hydroxides followed by freezing.     

Production of articles and powders based on stabilized zirconium dioxide

The Chepetskii Mechanical Works produces articles and powders based on ZrO₂ stabilized by Y₂O₃ (fully or partly) and CaO. The production volume is up to 1 ton per year. __________ Translated from Novye Ogneupory, No. 6, pp. 55–56, June, 2007.     

A strong ceramic based on aluminum oxide and zirconium dioxide

The theoretical premises and experimental results on fabrication of ceramics based on aluminum oxide with a regulatable structure which ensures high strength properties and the possibility of wide use in different areas of technology were reported. The effect of adding zirconium oxide to aluminum oxide on the structure and strength properties of the ceramics was demonstrated. New ceramic materials having a high strength were developed with highly disperse powders. The technological parameters of corundum ceramics of the “Koral” type and materials from mixtures of zirconium dioxide and aluminum oxide containing tetragonal and cubic solid solutions based on zirconium dioxide were developed. Stable results were obtained for the strength properties of ceramics made of special-purity tetragonal zirconium dioxide.     

Thermomechanical properties of zirconium dioxide concretes based on mechanochemical phosphate-containing binders

Thermomechanical properties of a highly refractory concrete based on ZrO₂ stabilized with 9–10 wt.% Y₂O₃ and phosphate-containing binder that is obtained by grinding ZrO₂ in an aqueous solution of H₃PO₄ are studied. The concrete obtained is distinguished by a low (about 1%) content of P₂O₅, high strength, and high resistance to heat. Thus it can be used as a reliable lining in high-temperature (>2300 K) heating units. Translated from Ogneupory i Tekhnicheskaya Keramika, No. 5, pp. 2–5, May, 1997.     

Adsorption of polyacrylamide on zirconium dioxide

The adsorption of an anionic-type polyelectrolyte (polyacrylamide) onto zirconium dioxide from aqueous dispersion has been studied as a function of pH. Polymer adsorption takes place in the acid region, obeying a Langmuir-type isotherm. Adsorption decreases with increasing pH. The zero-point of charge (zpc) at the ZrO₂–H₂O interface and the nature of the ionic charge on the polymer molecules were investigated. The behavior of polymer attachment is discussed on the grounds of a nonionic bonding mechanism including H bonding and of electrostatic interaction. It has been found that the zpc of ZrO₂ is at pH ～3.5 and that the ionic properties of the polymer molecules depend, to a noticeable extent, upon the pH of the medium.     

Producing a composite material based on zircon concentrate and nanocrystalline zirconium dioxide

The effects have been examined of adding nanocrystalline zirconium dioxide powder stabilized by yttrium oxide on the production and properties of a composite material based on zircon. It is found that the zirconium dioxide particles at the boundaries of the zircon grains slow the consolidation of the zircon matrix in sintering and zircon grain growth.     

Highly resistant dispensing nozzles based on zirconium dioxide for profiled CBCM. Part 1. Structure and physicomechanical properties of materials based on zirconium dioxide for producing CBCM dispensing nozzles

Technology is developed for preparing refractory components made of partially stabilized zirconium dioxide using an isostatic compaction press. Technology is provided for manufacturing dispensing nozzles using combined and separately stabilized zirconium dioxide, and also indices of the refractories obtained and imported materials are compared. __________ Translated from Novye Ogneupory, No. 3, pp. 127–131, March 2008.