Patent ID: 7964818

Claim:
A method of fabricating a yttria part, comprising: (a) providing a yttria sample; (b) sintering the yttria sample; (c) machining the sintered yttria sample to form a part; and (d) annealing the part to obtain a single-phase microcrystallite structure, wherein the annealing further comprises: (d1) exposing the part to an annealing gas in an enclosure; (d2) heating the part from a first temperature to a second temperature over a first time period, wherein the heating rate is controlled such that thermal gradient within the part does not exceed about 10 Joules per kilogram per Kelvin (J/kg-K); (d3) maintaining the part at the second temperature for a second time period; and (d4) cooling the part from the second temperature to the first temperature over a third time period.