METHOD FOR OBTAINING LIGHT-ABSORBING CERAMICS Russian patent published in 2022 - IPC C04B35/486 C04B35/626 C04B35/65 

FIELD: ceramic materials.

SUBSTANCE: invention relates to the technology of light-absorbing composite ceramic materials of the ZrO₂-Y₂O₃-Al₂O₃-TiO₂ composition with a high degree of emissivity and can be used for the manufacture of high-temperature thermal protection for aircraft, thermal insulation elements for high-temperature units and various special equipment products operated under significant thermal loads. For the manufacture of light-absorbing ceramics, the method for coprecipitation of zirconium, yttrium and aluminum hydroxides from a mixture of aqueous solutions of zirconium oxychloride, yttrium chloride and aluminum chloride with a concentration of 3-7% is used by interacting with an aqueous solution of ammonia. The oxide composition ZrO₂-Y₂O₃-Al₂O₃-TiO₂ is obtained by thermal treatment of co-precipitated hydroxides in air at 400-600°C for 60-120 minutes, then titanium powder (3-5 wt.%) with a particle size of 10-20 mcm is added to it. After obtaining a homogeneous powder mixture, it is pressed under a pressure of 100–300 MPa to manufacture powder blanks, which are heated in air to a temperature of 800–850°C in order to initiate the process of self-propagating high-temperature synthesis, followed by isothermal exposure for 15–30 minutes. Powder blanks are sintered in vacuum at a temperature of 1400–1425°C for 60–120 minutes.

EFFECT: increase in the emissivity of ceramics, an increase in its strength while maintaining high heat resistance.

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