# US 9,751,798 B2 · White, opaque,β-spodumene glass-ceramic articles with inherent damage resistance and methods for making the same

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- Number: US 9,751,798 B2
- Document ID: US9751798B2
- Status: Granted
- Kind: B2
- Application number: 14/751,402
- Filed: 2015-06-26
- Published: 2015-12-31
- Granted: 2017-09-05
- Earliest claimed: 2014-06-30
- Assignees: Corning Incorporated
- Applicants: Corning Incorporated
- Inventors: George Halsey Beall; Qiang Fu; Charlene Marie Smith; Randall Eugene Youngman
- Web page: https://patentgrep.com/patent/US9751798B2

## CPC

- C03B 32/02: Thermal crystallisation, e.g. for crystallising glass bodies into glass-ceramic articles {(C03B27/012 takes precedence)}
- C03C 3/093: containing zinc or zirconium
- C03C 3/097: containing phosphorus, niobium or tantalum
- C03C 10/0027: {containing SiO2, Al2O3, Li2O as main constituents}
- C03C 10/0054: {containing PbO, SnO2, B2O3}
- C03C 21/002: {to perform ion-exchange between alkali ions (C03C21/005 takes precedence)}
- C03C 2204/00: Glasses, glazes or enamels with special properties
- C03B: MANUFACTURE, SHAPING, OR SUPPLEMENTARY PROCESSES
- C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS

## Abstract

Crystallizable glasses, glass-ceramics, IXable glass-ceramics, and IX glass-ceramics are disclosed. The glass-ceramics exhibit β-spodumene ss as the predominant crystalline phase. These glasses and glass-ceramics, in mole %, include: 60-75 SiO2; 10-18 Al2O3; 5-14 Li2O; and 4.5 B2O3. The glass-ceramics also have a Vickers initiation crack threshold of at least about 25 kgf.

## Claims

### Claim 1

A glass-ceramic article comprising:
a) a composition, in mole %, comprising:
i) SiO2 in a range from about 60 to about 75,
ii) Al2O3 in a range from about 10 to about 18,
iii) Li2O in a range from about 5 to about 14, and
iv) B2O3 in a range from about 10 to about 20,
wherein a ratio of the mole sum total [Li2O+Na2O+K2O+MgO+ZnO]/moles of [Al2O3] is in a range from about 0.8 to about 1.5; and
b) a Vickers crack initiation threshold of a least about 25 kgf. wherein β-spodumene is the predominant crystalline phase.

### Claim 2 (depends on 1)

The glass-ceramic article of claim 1, wherein the Vickers crack initiation threshold is at least about 30 kgf.

### Claim 3 (depends on 1)

The glass-ceramic article of claim 1, wherein the Vickers crack initiation threshold is at least about 35 kgf.

### Claim 4 (depends on 1)

The glass-ceramic article of claim 1, wherein the Vickers crack initiation threshold is at least about 40 kgf.

### Claim 5 (depends on 1)

The glass-ceramic article of claim 1, wherein the Vickers crack initiation threshold is at least about 45 kgf.

### Claim 6 (depends on 1)

The glass-ceramic article of claim 1, wherein at least about 50% of the B2O3 present in a residual glass comprises three-fold coordination boron cations.

### Claim 7 (depends on 1)

The glass-ceramic article of claim 1, wherein the composition further comprises:
v) MgO in a range from 0 to about 8,
vi) ZnO in a range from 0 to about 4,
vii) TiO2 in a range from about 2 to about 5,
viii) Na2O in a range from 0 to about 5,
ix) K2O in a range from 0 to about 4, and
x) SnO2 in a range from about 0.05 to about 0.5.

### Claim 8 (depends on 1)

The glass-ceramic article of claim 1, wherein the composition, in mole %, comprises:
i) SiO2 in a range from about 60 to about 70,
ii) Al2O3 in a range from about 10 to about 16,
iii) Li2O in a range from about 7 to about 10,
iv) B2O3 in a range from about 6 to about 8,
v) MgO in a range from about 2 to about 5,
vi) ZnO in a range from about 1 to about 2,
vii) TiO2 in a range from about 3 to about 4,
viii) Na2O in a range from about 0.4 to about 0.6, and
ix) SnO2 in a range from about 0.2 to about 0.5.

### Claim 9 (depends on 1)

The glass-ceramic article of claim 1, wherein the composition comprises B2O3 in a range from about 6 to about 10 mole %.

### Claim 10 (depends on 1)

The glass-ceramic article of claim 1, wherein the composition comprises B2O3 in a range from about 6 to about 8 mole %.

### Claim 11 (depends on 1)

The glass-ceramic article of claim 1, wherein the composition comprises ZrO2 in a range from 0 to about 3 mole %.

### Claim 12 (depends on 1)

The glass-ceramic article of claim 1, wherein the glass-ceramic article comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
a) CIE a* in a range from about −2 to about 1;
b) CIE b* in a range from about −5 to about −2; and
c) CIE L* in a range from about 80 to about 98.

### Claim 13 (depends on 1)

The glass-ceramic article of claim 1, further comprising a compressive stress layer formed by ion-exchange.

### Claim 14 (depends on 13)

The glass-ceramic article of claim 13, wherein the compressive stress layer has a compressive stress of at least 80 MPa and a depth of layer (DOL) of at least about 2% of an overall thickness of the article.

### Claim 15 (depends on 1)

An electronic device comprising the glass-ceramic article of claim 1.

### Claim 16

A glass-ceramic article comprising:
a) a composition, in mole %, comprising:
i) SiO2 in a range from about 60 to about 75,
ii) Al2O3 in a range from about 10 to about 18,
iii) Li2O in a range from about 5 to about 14,
iv) B2O3 in a range from about 8 to about 20,
v) TiO2 in a range from about 2 to about 5, and
vi) SnO2 in a range from about 0.05 to about 0.5; and
b) a Vickers crack initiation threshold of a least about 25 kgf,
wherein β-spodumene is the predominant crystalline phase.

### Claim 17 (depends on 16)

The glass-ceramic article of claim 16, wherein the composition further comprises:
vii) MgO in a range from 0 to about 8,
viii) ZnO in a range from 0 to about 4,
ix) Na2O in a range from 0 to about 5, and
x) K2O in a range from 0 to about 4.

### Claim 18 (depends on 16)

The glass-ceramic article of claim 16, wherein the Vickers crack initiation threshold is at least about 30 kgf.

### Claim 19 (depends on 16)

The glass-ceramic article of claim 16, wherein the Vickers crack initiation threshold is at least about 35 kgf.

### Claim 20 (depends on 16)

The glass-ceramic article of claim 16, wherein the Vickers crack initiation threshold is at least about 40 kgf.

### Claim 21 (depends on 16)

The glass-ceramic article of claim 16, wherein the Vickers crack initiation threshold is at least about 45 kgf.

### Claim 22 (depends on 16)

The glass-ceramic article of claim 16, wherein at least about 50% of the B2O3 present in a residual glass comprises three-fold coordination boron cations.

### Claim 23 (depends on 16)

The glass-ceramic article of claim 16, wherein the composition comprises ZrO2 in a range from 0 to about 3 mole %.

### Claim 24 (depends on 16)

The glass-ceramic article of claim 16, wherein the glass-ceramic article comprises a color presented in CIELAB color space coordinates for an observer angle of 10° and a CIE illuminant F02 determined from reflectance spectra measurements using a spectrophotometer with specular reflectance included comprising:
a) CIE a* in a range from about −2 to about 1;
b) CIE b* in a range from about −5 to about −2; and
c) CIE L* in a range from about 80 to about 98.

### Claim 25 (depends on 16)

The glass-ceramic article of claim 16, further comprising a compressive stress layer formed by ion-exchange.

### Claim 26 (depends on 25)

The glass-ceramic article of claim 25, wherein the compressive stress layer has a compressive stress of at least 80 MPa and a depth of layer (DOL) of at least about 2% of an overall thickness of the article.

### Claim 27 (depends on 16)

An electronic device comprising the glass-ceramic article of claim 16.

### Claim 28 (depends on 16)

The glass-ceramic article of claim 16, wherein a ratio of the mole sum total [Li2O+Na2O+K2O+MgO+ZnO]/moles of [Al2O3] is in a range from about 0.8 to about 1.5.