Patent ID: 8278231

Claim:
A heat stable, formed ceramic component, said component comprising: a multimodal grain distribution including: (i) at least 50 wt % of coarse grains including partially stabilized zirconia, said coarse grains comprising a D50 grain size in the range of from 5 to 800 μm, based upon the total weight of said component wherein said partially stabilized zirconia comprises 1 mole % to 7 mole % yttria per mole of partially stabilized zirconia; and (ii) at least 1 wt % of fine grains comprising a D50 average grain size not greater than one-fourth the D50 grain size of said coarse grain, dispersed within said coarse grains, based upon the total weight of said component; wherein (a) after sintering, said component has porosity at ambient temperature in the range of from 5 to 45 vol. %, based on the volume of said formed component, (b) wherein said fine grains have a grain mode comprises a D50 grain size of from 0.05 μm to 5.0 μm, and said grains have a grain mode comprises a D50 grain size of from 20 μm to 200 μm, and (c) wherein said fine grains consist essentially of a stabilizer or a stabilized zirconia.