Hot-molding of stabilized zirconia produced by hydroxide coprecipitation.

Autor: Lipilin, A., Neuimin, A., Pal'guev, S., Gul'bis, F.
Zdroj: Refractories; 1974, Vol. 15 Issue 7/8, p508-512, 5p
Abstrakt: An investigation was carried out of the apparent density, open porosity, crystalline structure and electrical conductance of specimens produced by hot-molding from powders of ZrO + ScO. The compounds were mixed by coprecipitating their hydroxides. An analysis was made of the effect of the temperature of the preliminary heat treatment of the mixture of hydroxides, of activating additives, and of the conditions of molding. It was established that the temperature of the preliminary heat treatment is not a significant factor in the density of the molded specimens and that at a roasting temperature of 450°C the density increases slightly. The addition of NHCl, ZrOCl or ScCl to the molding powder gives denser and less porous moldings. Even at a relatively low molding temperature (1300°C) the presence of NHCl or ZrOCl results in a density of 5.5 g/cm. The electrical conductivity of specimens produced by hot-molding the coprecipitated hydroxides is higher after a heat treatment in an oxidizing medium than that of specimens produced by the conventional ceramic method. In terms of the crystalline structure the hot-molded specimens do not differ from those produced by the conventional method. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index
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