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US 11,840,476 B2Granted
Zirconia-toughened glass ceramics
AssigneeCorning Incorporated
InventorsGeorge Halsey Beall, Qiang Fu, Charlene Marie Smith
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Abstract
ZrO2-toughened glass ceramics having high molar fractions of tetragonal ZrO2 and fracture toughness value of greater than 1.8 MPa·m1/2. The glass ceramic may also include also contain other secondary phases, including lithium silicates, that may be beneficial for toughening or for strengthening through an ion exchange process. Additional second phases may also decrease the coefficient of thermal expansion of the glass ceramic. A method of making such glass ceramics is also provided.
Claims24
A glass ceramic comprising:
- a first crystalline phase comprising:
- a tetragonal ZrO2 phase;
- a second crystalline phase comprising a lithium silicate;
- and
- a residual glass phase;
- wherein the glass ceramic comprises a fracture toughness of from 1 to 10 MPa·m1/2, as measured by Chevron notch short bar methods;
- and
- wherein the tetragonal ZrO2 comprises a weight percent (wt %) of the total ZrO2 in the glass ceramic, measured as the (((weight of the tetragonal ZrO2)/(total weight of ZrO2 in the glass ceramic))*100), and wherein the tetragonal ZrO2 comprises 40-95 wt % of ZrO2 in the glass ceramic.
5 more elements
A glass ceramic comprising:
- a first crystalline phase comprising:
- a tetragonal ZrO2 phase;
- a second crystalline phase comprising a lithium silicate;
- and
- a residual glass phase;
- wherein the glass ceramic comprises a fracture toughness of from 1 to 10 MPa.m1/2, as measured by Chevron notch short bar methods;
- and
- wherein the glass ceramic comprises:
- 58-69 mol% SiO2
- 25-36 mol% Li2O
- 6-15 mol% ZrO2
- >0-5 mol% Al2O3
- 0-5 mol% Na2O
- 0-5 mol% B2O3
- 0.2-3 mol% P2O5
- 0-8 mol% MO, wherein MO is the sum of the alkaline earth metal oxides MgO, CaO, SrO, and BaO,
- >0-5 mol% TMO, wherein TMO is the sum of oxides of metals in groups IVB-VIII, IB, and IIB, or 4-12 in the periodic table, and
- 0-5 mol% REO, wherein REO is the sum of oxides Sc2O3, Y2O3, and the lanthanides La2O3, Ce2O3, Pr2O3, Nd2O3, Pm2O3, Sm2O3, Eu2O3, Gd2O3, Tb2O3, Dy2O3, Ho2O3, Er2O3, Tm2O3, Yb2O3, and Lu2O3.
15 more elements
Dependencies are inferred from the claim text.