METHOD FOR PRODUCING CERAMIC COMPOSITES BASED ON LANTHANUM ORTHOPHOSPHATE Russian patent published in 2023 - IPC C04B35/447 C04B35/624 B82Y40/00 

FIELD: ceramic composites.

SUBSTANCE: invention relates to methods for producing ceramic composites based on lanthanum orthophosphate (LaPO₄-Al₂O₃, LaPO₄-Y₂O₃, LaPO₄-ZrO₂) from nanosized precursor powders. At the first stage, a lanthanum orthophosphate sol is obtained by reverse precipitation by adding lanthanum nitrate to an aqueous solution of monosubstituted ammonium phosphate. A metal hydroxide sol selected from the group of aluminium, zirconium, yttrium is obtained by reverse precipitation by adding an aqueous solution of an aluminium, yttrium or zirconium salt to an aqueous solution of ammonia and precipitation at pH 8-9. The resulting colloidal solutions are poured together, followed by the maturation of the precursor gel, washing, filtering, drying and grinding. To form composite ceramics, the obtained nanosized powder is ground, pressed and sintered at a temperature of 1200-1300°C.

EFFECT: obtaining composite ceramics with increased microhardness, low porosity and high chemical resistance, which makes it possible to use it for the manufacture of structural elements in power plants, in particular, as heat shields in high-temperature microturbine generators for small-scale power generation, as well as matrices for the immobilization of high-level waste (HLW) of nuclear energy.

2 cl, 9 dwg, 2 tbl