Ceramic article with reduced surface defect density and process for producing a ceramic article

A method comprising:

• receiving a machined and heat treated ceramic article comprising a bulk sintered rare earth oxide that has been used in a plasma etch process, wherein the machined and heat treated ceramic article has a surface defect density level caused by the plasma etch process;
• heating the machined and heat treated ceramic article to a temperature range between about 1000° C. and about 1800° C.;
• heat treating the machined and heat treated ceramic article at one or more temperatures within the temperature range for a duration of up to about 24 hours;
• and
• cooling the machined and heat treated ceramic article, wherein after completing the heat treating the machined and heat treated ceramic article has a new surface defect density level below the surface defect density level caused by the plasma etch process.

A method comprising:

• heating a machined ceramic article to a temperature range between about 1000° C. and about 1800° C., the machined ceramic article having an initial surface defect density and an initial surface roughness, wherein the machined ceramic article comprises an uncoated bulk sintered ceramic comprising a compound of Y4Al2O9 (YAM) and a solid-solution of Y2O3—ZrO2 (Y2-xZrxO3);
• heat treating the machined ceramic article at one or more temperatures within the temperature range for a duration of up to about 24 hours;
• and
• cooling the machined ceramic article, wherein after the heat treatment the machined ceramic article has a reduced surface defect density and a reduced surface roughness.