Patent ID: 11472743

Abstract:
A sintered bead with the following crystal phases, in percentages by mass based on crystal phases: 25%≤zircon, or “Z1”, ≤94%; 4%≤stabilized zirconia+stabilized hafnia, or “Z2”, ≤61%; monoclinic zirconia+monoclinic hafnia, or “Z3”≤50%; corundum≤57%; crystal phases other than Z1, Z2, Z3 and corundum<10%; the following chemical composition, in percentages by mass based on oxides: 33%≤ZrO2+HfO2, or “Z4”≤83.4%; HfO2≤2%; 10.6%≤SiO2≤34.7%; Al2O3≤50%; 0%≤Y2O3, or “Z5”; 0%≤CeO2, or “Z6”; 0.3%≤CeO2+Y2O3≤19%, provided that (1) CeO2+3.76*Y2O3≥0.128*Z, and (2) CeO2+1.3*Y2O3≤0.318*Z, with Z=Z4+Z5+Z6−(0.67*Z1*(Z4+Z5+Z6)/(0.67*Z1+Z2+Z3)); MgO≤5%; CaO≤2%; oxides other than ZrO2, HfO2, SiO2, Al2O3, MgO, CaO, CeO2 and Y2O3<5.0%.