Shaped sintered ceramic bodies composed of Y2O3-stabilized zirconium oxide and process for producing a shaped sintered ceramic body composed of Y2O3-stabilized zirconium oxide

A ceramic sintered shaped body, wherein the sintered shaped body comprises Y2O3-stabilized zirconia and 2-15 mass % of unstabilized zirconia and has

• a sintered density of at least 99% of a theoretical sintered density;
• a mean grain size of smaller than 180 nm;
• a zirconia fraction comprising tetragonal and cubic phases in a concentration of at least 98 mass %;
• and
• a monoclinic fraction of less than 3 mass % after 120 hours at 134° C. and 2 bar in a water vapor atmosphere.

A ceramic sintered shaped body, wherein the sintered shaped body comprises Y2O3-stabilized zirconia and 0.2-20 mass % of α-Al2O3 and has

• a sintered density of at least 99% of a theoretical sintered density;
• a mean grain size of smaller than 180 nm;
• a zirconia fraction comprising tetragonal and cubic phases in a concentration of at least 98 mass %;
• and
• a monoclinic fraction of less than 3 mass % after 120 hours at 134° C. and 2 bar in a water vapor atmosphere.