Glass-ceramic and methods of making the same

1. A glass-ceramic, comprising:

a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 , where x≤1;

a second crystal phase including tetragonal ZrO 2 ,

wherein the glass-ceramic is free of arsenic, tin, antimony, and cesium,

wherein the glass-ceramic comprises a transmittance of at least 80% to light having a wavelength of 380 nm to 760 nm, and

further wherein the glass-ceramic is derived from a glass-ceramic precursor composition that comprises:

SiO 2 from 54% to about 59%,

Al 2 O 3 from 19% to about 30%,

ZnO from about 0% to about 20%,

ZrO 2 from about 4% to about 6%, and

MgO from about 0.01% to about 20% (by mole of oxide);

further wherein the glass-ceramic further comprises:

a CIE LAB L* value greater than about 90;

a CIE LAB a* value of about −0.2 to about 0.2; and

a CIE LAB b* value of about −0.1 to about 0.8,

wherein L*, a*, and b* are each measured at an angle of incidence (AOI) of 10 degrees with a D65 illuminant at a wavelength range of 380 nm to 760 nm.

2. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises at least one of:

a crystallinity of at least about 10% (by weight); and

a crystallite size of the first crystal phase of less than about 20 nm.

3. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises at least one of:

an absorbance of less than about 0.5 absorbance units/millimeter (a.u./mm) for light having a wavelength of 300 nm;

an absorbance of less than about 0.15 absorbance units/millimeter (a.u./mm) for light having a wavelength of 350 nm; and

an absorbance of less than about 0.1 absorbance units/millimeter (a.u./mm) for light having a wavelength of 500 nm to 800 nm.

4. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises a total crystallinity of 15 wt % to 40 wt %.

5. The glass-ceramic of claim 1 , further comprising at least one of:

Fe 2 O 3 at less than about 0.02% (by weight); and

a ratio of an Fe 2+ content to a total iron content (Fe 2+ +Fe 3+ ) of less than about 0.5.

6. The glass-ceramic of claim 1 , further comprising:

Na 2 O at greater than about 2% (by mole of oxide).

7. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises at least one of:

a maximum hardness of about 8 GPa to about 15 GPa, as measured by a Berkovich nanoindenter; and

a modulus of elasticity of about 90 GPa to about 120 GPa, as measured using resonant ultrasonic spectroscopy.

8. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises at least one of:

a haze value of less than about 0.7% for light having a wavelength of 300 nm;

a haze value of less than about 0.5% for light having a wavelength of 350 nm; and

a haze value of less than about 0.3% for light having a wavelength of 400 nm to 800 nm.

9. The glass-ceramic of claim 1 , wherein the glass-ceramic further comprises at least one of:

an axial transmittance of at least about 30% to light having a wavelength of 300 nm;

an axial transmittance of at least about 65% to light having a wavelength of 350 nm;

an axial transmittance of at least about 85% to light having a wavelength of 450 nm; and

an axial transmittance of at least about 85% to light having a wavelength of 500 nm to 800 nm.

10. A method of making a glass-ceramic, comprising:

forming a glass-ceramic precursor from a composition comprising:

SiO 2 from 54% to about 59%,

Al 2 O 3 from 19% to about 30%,

ZnO from about 0% to about 20%,

ZrO 2 from about 4% to about 6%, and

MgO from about 0.01% to about 20% (by mole of oxide); and

heating the glass-ceramic precursor to form a glass-ceramic article comprising:

a first crystal phase including (Mg x Zn 1-x )Al 2 O 4 , where x is ≤1; and

a second crystal phase including tetragonal ZrO 2 ,

wherein the glass-ceramic is free of arsenic, tin, antimony, and cesium, and

wherein the glass-ceramic is characterized by a transmittance of at least 80% to light having a wavelength of 380 nm to 760 nm,

wherein, the glass-ceramic comprises:

a CIE LAB L* value greater than about 90;

a CIE LAB a* value of about −0.2 to about 0.2; and

a CIE LAB b* value of about −0.1 to about 0.8,

wherein L*, a*, and b* are each measured at an angle of incidence (AOI) of 10 degrees with a D65 illuminant at a wavelength range of 380 nm to 760 nm.

11. The method of claim 10 , wherein a raw material source of the SiO 2 comprises less than 0.002% Fe 2 O 3 (by weight).

12. The method of claim 10 , wherein the glass-ceramic further comprises at least one of:

Fe 2 O 3 at less than about 0.02% (by weight); and

a ratio of an Fe 2+ content to a total iron content (Fe 2+ +Fe 3+ ) of less than about 0.2.

13. The method of claim 10 , wherein the glass-ceramic precursor composition further comprises:

Na 2 O at greater than about 2% (by mole of oxide).