Patent ID: 9266782
Filing Date: 2016-02-23
CPC Classification: C03B,C04B

Claim Text:
1. A method for making a ceramic block consisting essentially of substantially homogeneous (Y 2 O 3 ) x .P 2 O 5 , where 0.95≦x≦1.05, having a length LL, a width WW and a height MI, and a volume VV of at least 8x10 −3 m 3 , essentially free of cracks throughout the volume, a density of at least 85% of the theoretical maximal density of Y 2 O 3 .P 2 O 5 under standard conditions, and a creep rate at 1250° C. and 6.89 MPa of CR, where CR ≦8.0x10 −6 hour −1 , comprising the following steps: (I) providing a dry powder of Y (II) mixing the powder of Y (III) sintering the powder mixture obtained in step (II) in a first furnace to obtain a precursor ceramic material having a composition (Y (IV) crushing the precursor ceramic material obtained in step (III) to obtain a plurality of particles; (V) forming a first green body having a volume larger than VV, of the ceramic block by mixing uniformly the plurality of particles obtained in step (IV) with an organic binder; (VI) isopressing the first green body obtained in step (VII) at a pressure of at least 50 MPa to obtain a second green body having a density at standard conditions of at least 60% of the theoretical maximal density of Y (VII) heating the second green body in a second furnace to a temperature of at least 1500° C., wherein step (VII) comprises: (VII.1) increasing the temperature of the furnace from 200° C. to 1500° C. at an average temperature elevation rate of not higher than 50° C/hour; and (VII.2) maintaining the temperature of the furnace at over 1500° C. for at least 100 hours.