阅读说明：本技术 黑色的锂硅酸盐玻璃陶瓷 (Black lithium silicate glass ceramic ) 是由 G·H·比尔 付强 C·M·史密斯 于 2018-11-29 设计创作，主要内容包括：提供了一种黑色锂硅酸盐玻璃陶瓷。玻璃陶瓷包含锂硅酸盐作为主晶相以及作为次晶相的以下至少一种：透锂长石、β-石英、β-锂辉石、方石英和锂磷酸盐。玻璃陶瓷表征为如下色坐标：L*为20.0至40.0；a*为-1.0至1.0；以及b*为-5.0至2.0。玻璃陶瓷可以经过离子交换。还提供了玻璃陶瓷的生产方法。(A black lithium silicate glass-ceramic is provided. The glass-ceramic comprises lithium silicate as a primary crystalline phase and at least one of the following as a secondary crystalline phase: petalite, beta-quartz, beta-spodumene, cristobalite, and lithium phosphate. The glass-ceramic is characterized by the following color coordinates: l is 20.0 to 40.0; a is-1.0 to 1.0; and b is-5.0 to 2.0. The glass-ceramic may be ion exchanged. A method for producing the glass-ceramic is also provided.)

1. A glass-ceramic, comprising:

at least one lithium silicate crystalline phase as a main crystalline phase; and

at least one of petalite, beta-quartz, beta-spodumene, cristobalite and lithium phosphate as a secondary crystal phase,

wherein the glass-ceramic is characterized by the following color coordinates:

l is 20.0 to 40.0;

a is-1.0 to 1.0; and

b is-5.0 to 2.0.

2. The glass-ceramic of claim 1 wherein the primary crystalline phase is lithium metasilicate.

3. The glass-ceramic of claim 1 wherein the primary crystalline phase is lithium disilicate.

4. The glass-ceramic of any one of claims 1 to 3, wherein the glass-ceramic has a transmittance in the visible range of less than 1%.

5. The glass-ceramic of any one of claims 1 to 4, wherein the ring-on-ring strength of the glass-ceramic is at least 290 MPa.

6. The glass-ceramic of any of claims 1 through 5, wherein the glass-ceramic has a fracture toughness of greater than or equal to 0.9 MPa-m^0.5To less than or equal to 2.0MPa m^0.5。

7. The glass-ceramic of any of claims 1 through 6, wherein the glass-ceramic has a fracture toughness of greater than or equal to 1.0 MPa-m^0.5To less than or equal to 1.5MPa m^0.5。

8. The glass-ceramic of any one of claims 1 to 7, further comprising:

55.0 to 75.0 wt.% SiO₂；

2.0 to 20.0 wt.% Al₂O₃；

0 to 5.0 wt.% B₂O₃；

5.0 to 15.0 wt.% Li₂O；

0 to 5.0 wt.% Na₂O；

0 to 4.0 wt.% K₂O；

0 to 8.0 wt.% MgO;

0 to 10.0 wt% ZnO;

0.5 to 5.0 wt% TiO₂；

1.0 to 6.0 wt.% P₂O₅；

2.0 to 10.0 wt.% ZrO₂；

0 to 0.4% by weight of CeO₂；

0.05 to 0.5 wt.% SnO + SnO₂；

0.1 to 5.0 wt.% FeO + Fe₂O₃；

0.1 to 5.0 wt% NiO;

0.1 to 5.0 wt.% Co₃O₄；

0 to 4.0 wt.% MnO + MnO₂+Mn₂O₃；

0 to 2.0 wt.% Cr₂O₃；

0 to 2.0 wt% CuO; and

0 to 2.0 wt.% V₂O₅。

9. The glass-ceramic of any one of claims 1 to 8, further comprising:

65.0 to 75.0 wt.% SiO₂；

7.0 to 11.0 wt.% Al₂O₃；

6.0 to 11.0 wt.% Li₂O；

2.0 to 4.0 wt% TiO₂；

1.5 to 2.5 wt.% P₂O₅；

2.0 to 4.0 wt.% ZrO₂；

1.0 to 4.0 wt.% FeO + Fe₂O₃；

0.5 to 1.5 wt% NiO; and

0.1 to 0.4 wt.% Co₃O₄。

10. The glass-ceramic of any one of claims 1 through 9, wherein the glass-ceramic has a crystallinity of greater than 50 weight percent.

11. The glass-ceramic of any of claims 1 through 10, wherein the glass-ceramic is ion exchanged and comprises a compressive stress layer extending from a surface of the glass-ceramic to a depth of compression.

12. The glass-ceramic of claim 11 wherein the compressive stress of the glass-ceramic at the surface is at least 250 MPa.

13. The glass-ceramic of claim 11 or 12, wherein the compressive stress of the glass-ceramic at the surface is greater than or equal to 250MPa to less than or equal to 650 MPa.

14. The glass ceramic of any one of claims 11 to 13, wherein the depth of compression is at least 0.05t, where t is the thickness of the glass ceramic.

15. The glass-ceramic of any one of claims 11 to 14, wherein the ring-on-ring strength of the glass-ceramic is at least 900 MPa.

16. A consumer electronic product, comprising:

a housing comprising a front surface, a back surface, and side surfaces;

an electronic assembly at least partially located within the housing, the electronic assembly including at least a controller, a memory, and a display, the display located at or adjacent to a front surface of the housing; and

a cover glass disposed over the display,

wherein at least a portion of the housing comprises the glass-ceramic of any of claims 1-10.

17. A consumer electronic product, comprising:

a housing comprising a front surface, a back surface, and side surfaces;

an electronic assembly at least partially located within the housing, the electronic assembly including at least a controller, a memory, and a display, the display located at or adjacent to a front surface of the housing; and

a cover glass disposed over the display,

wherein at least a portion of the housing comprises the glass-ceramic of any of claims 11 to 15.

18. A method, comprising:

ceramming the precursor glass-based article to form a glass-ceramic,

wherein the glass-ceramic comprises:

at least one lithium silicate crystalline phase as a main crystalline phase; and

petalite, beta-quartz, beta-spodumene, cristobalite and lithium phosphate as a secondary crystal phase, and

the glass-ceramic is characterized by the following color coordinates:

l is 20.0 to 40.0;

a is-1.0 to 1.0; and

b is-5.0 to 2.0.

19. The method of claim 18, wherein the ceramming is performed at a temperature of greater than or equal to 500 ℃ to less than or equal to 900 ℃.

20. The method of claim 18 or 19, wherein ceramming is performed for a period of time greater than or equal to 6 hours to less than or equal to 16 hours.

21. The method of any one of claims 18 to 20, further comprising ion exchanging the glass-ceramic.

22. The method of any of claims 18 to 21, wherein the precursor glass-based article comprises:

55.0 to 75.0 wt.% SiO₂；

2.0 to 20.0 wt.% Al₂O₃；

0 to 5.0 wt.% B₂O₃；

5.0 to 15.0 wt.% Li₂O；

0 to 5.0 wt.% Na₂O；

0 to 4.0 wt.% K₂O；

0 to 8.0 wt.% MgO;

0 to 10.0 wt% ZnO;

0.5 to 5.0 wt% TiO₂；

1.0 to 6.0 wt.% P₂O₅；

2.0 to 10.0 wt.% ZrO₂；

0 to 0.4% by weight of CeO₂；

0.05 to 0.5 wt.% SnO + SnO₂；

0.1 to 5.0 wt.% FeO + Fe₂O₃；

0.1 to 5.0 wt% NiO;

0.1 to 5.0 wt.% Co₃O₄；

0 to 4.0 wt.% MnO + MnO₂+Mn₂O₃；

0 to 2.0 wt.% Cr₂O₃；

0 to 2.0 wt% CuO; and

0 to 2.0 wt.% V₂O₅。

23. The method of any of claims 18 to 22, wherein the precursor glass-based article comprises:

65.0 to 75.0 wt.% SiO₂；

7.0 to 11.0 wt.% Al₂O₃；

6.0 to 11.0 wt.% Li₂O；

2.0 to 4.0 wt% TiO₂；

1.5 to 2.5 wt.% P₂O₅；

2.0 to 4.0 wt.% ZrO₂；

1.0 to 4.0 wt.% FeO + Fe₂O₃；

0.5 to 1.5 wt% NiO; and

0.1 to 0.4 wt.% Co₃O₄。

24. A glass, comprising:

55.0 to 75.0 wt.% SiO₂；

2.0 to 20.0 wt.% Al₂O₃；

0 to 5.0 wt.% B₂O₃；

5.0 to 15.0 wt.% Li₂O；

0 to 5.0 wt.% Na₂O；

0 to 4.0 wt.% K₂O；

0 to 8.0 wt.% MgO;

0 to 10.0 wt% ZnO;

0.5 to 5.0 wt% TiO₂；

1.0 to 6.0 wt.% P₂O₅；

2.0 to 10.0 wt.% ZrO₂；

0 to 0.4% by weight of CeO₂；

0.05 to 0.5 wt.% SnO + SnO₂；

0.1 to 5.0 wt.% FeO + Fe₂O₃；

0.1 to 5.0 wt% NiO;

0.1 to 5.0 wt.% Co₃O₄；

0 to 4.0 wt.% MnO + MnO₂+Mn₂O₃(ii) a 0 to 2.0 wt.% Cr₂O₃；

0 to 2.0 wt% CuO; and 0 to 2.0 wt.% V₂O₅。

25. The glass of claim 24, comprising:

65.0 to 75.0 wt.% SiO₂；

7.0 to 11.0 wt.% Al₂O₃；

6.0 to 11.0 wt.% Li₂O；

2.0 to 4.0 wt% TiO₂；

1.5 to 2.5 wt.% P₂O₅；

2.0 to 4.0 wt.% ZrO₂；

1.0 to 4.0 wt.% FeO + Fe₂O₃；

0.5 to 1.5 wt% NiO; and

0.1 to 0.4 wt%.

Technical Field

The present description relates generally to glass-ceramic compositions. More particularly, the present description relates to black lithium silicate glass-ceramics that can form housings for electronic devices.

Background

Portable electronic devices, such as smartphones, tablets, and wearable devices (e.g., watches and fitness trackers), continue to become smaller and more complex. As such, the materials conventionally used on at least one exterior surface of such portable electronic devices continue to become more complex. For example, as portable electronic devices become smaller and thinner to meet consumer demand, the housings for these portable electronic devices also become smaller and thinner, resulting in higher performance requirements for the materials used to form these components.

Therefore, there is a need for materials exhibiting higher performance (e.g., damage resistance) and aesthetic appearance for use in portable electronic devices.

Disclosure of Invention

According to aspect (1), a glass-ceramic is provided. The glass-ceramic comprises: at least one lithium silicate crystalline phase as a main crystalline phase; and as a secondary crystalline phase at least one of: petalite, beta-quartz, beta-spodumene, cristobalite, and lithium phosphate. The glass-ceramic is characterized by the following color coordinates: l is 20.0 to 40.0; a is-1.0 to 1.0; and b is-5.0 to 2.0.

According to aspect (2), there is provided the glass-ceramic of aspect (1), wherein the main crystal phase is lithium metasilicate.

According to aspect (3), there is provided the glass-ceramic of aspect (1) or (2), wherein the main crystal phase is lithium disilicate.

According to aspect (4), there is provided the glass-ceramic of any one of aspects (1) to (3), wherein the glass-ceramic has a transmittance in the visible light range of less than about 1%.

According to aspect (5), there is provided the glass-ceramic of any one of aspects (1) to (4), wherein the glass-ceramic has an annular ring strength of at least about 290 MPa.

According to aspect (6), there is provided the glass-ceramic of any one of aspects (1) to (5), wherein the glass-ceramic has a fracture toughness of about 0.9 MPa-m^0.5To about 2.0MPa m^0.5。

According to aspect (7), there is provided the glass-ceramic of any one of aspects (1) to (8), wherein the glass-ceramic has a fracture toughness of about 1.0 MPa-m^0.5To about 1.5MPa m^0.5。

According to aspect (8), there is provided the glass-ceramic of any one of aspects (1) to (7), further comprising: about 55.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 2.0 wt.% to about 20.0 wt.% Al₂O₃(ii) a 0 wt.% to about 5.0 wt.% B₂O₃(ii) a About 5.0 wt% to about 15.0 wt% Li₂O; 0 wt.% to about 5.0 wt.% Na₂O; 0 wt.% to about 4.0 wt.% K₂O; 0 wt% to about 8.0 wt% MgO; 0 wt% to about 10.0 wt% ZnO; about 0.5 wt% to about 5.0 wt% TiO₂(ii) a About 1.0 wt.% to about 6.0 wt.% P₂O₅(ii) a About 2.0 wt% to about 10.0 wt% ZrO₂(ii) a 0 wt.% to about 0.4 wt.% CeO₂(ii) a About 0.05 wt.% to about 0.5 wt.% SnO + SnO₂(ii) a About 0.1 wt.% to about 5.0 wt.% FeO + Fe₂O₃(ii) a About 0.1 wt% to about 5.0 wt% NiO; about 0.1 wt% to about 5.0 wt% Co₃O₄(ii) a 0 wt% to about 4.0 wt% MnO + MnO₂+Mn₂O₃(ii) a 0 weight (l)% to about 2.0 wt.% Cr₂O₃(ii) a 0 wt% to about 2.0 wt% CuO; and 0 wt% to about 2.0 wt% V₂O₅。

According to aspect (9), there is provided the glass-ceramic of any one of aspects (1) to (8), further comprising: about 65.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 7.0 wt.% to about 11.0 wt.% Al₂O₃(ii) a About 6.0 wt% to about 11.0 wt% Li₂O; about 2.0 wt% to about 4.0 wt% TiO₂(ii) a About 1.5 wt.% to about 2.5 wt.% P₂O₅(ii) a About 2.0 wt% to about 4.0 wt% ZrO₂(ii) a About 1.0 wt.% to about 4.0 wt.% FeO + Fe₂O₃(ii) a About 0.5 wt% to about 1.5 wt% NiO; and about 0.1 wt% to about 0.4 wt% Co₃O₄。

According to aspect (10), there is provided the glass-ceramic of any one of aspects (1) to (9), wherein the glass-ceramic has a crystallinity of greater than about 50 wt.%.

According to aspect (11), there is provided the glass-ceramic of any one of aspects (1) to (10), wherein the glass-ceramic is ion-exchanged and comprises a compressive stress layer extending from a surface of the glass-ceramic to a depth of compression.

According to aspect (12), there is provided the glass-ceramic of aspect (11), wherein the glass-ceramic has a compressive stress at the surface of at least about 250 MPa.

According to aspect (13), there is provided the glass-ceramic of aspect (11) or (12), wherein the glass-ceramic has a compressive stress at the surface of about 250MPa to about 650 MPa.

According to aspect (14), there is provided the glass-ceramic of any one of aspects (11) to (13), wherein the depth of compression is at least 0.05t, where t is the thickness of the glass-ceramic.

According to aspect (15), there is provided the glass-ceramic of any one of aspects (11) to (14), wherein the glass-ceramic has a ring-on-ring strength of at least about 900 MPa.

According to an aspect (16), a consumer electronics product is provided. The consumer electronic product includes: a housing comprising a front surface, a back surface, and side surfaces; an electronic assembly at least partially within the housing, the electronic assembly including at least a controller, a memory, and a display, the display being located at or adjacent to the front surface of the housing; and a cover glass disposed over the display. At least a portion of the housing comprises the glass-ceramic of any one of aspects (1) to (10).

According to an aspect (17), a consumer electronics product is provided. The consumer electronic product includes: a housing comprising a front surface, a back surface, and side surfaces; an electronic assembly at least partially within the housing, the electronic assembly including at least a controller, a memory, and a display, the display being located at or adjacent to the front surface of the housing; and a cover glass disposed over the display. At least a portion of the housing comprises the glass-ceramic of any one of aspects (11) to (15).

According to aspect (18), a method is provided. The method comprises the following steps: a precursor glass-based article is cerammed to form a glass-ceramic. The glass-ceramic comprises: at least one lithium silicate crystalline phase as a main crystalline phase; and as a secondary crystalline phase at least one of: petalite, beta-quartz, beta-spodumene, cristobalite, and lithium phosphate. The glass-ceramic is characterized by the following color coordinates: l is 20.0 to 40.0; a is-1.0 to 1.0; and b is-5.0 to 2.0.

According to aspect (19), there is provided the method of aspect (18), wherein the ceramizing is performed at a temperature of about 500 ℃ to about 900 ℃.

According to aspect (20), there is provided the method of aspect (18) or (19), wherein the ceramming is performed for a period of about 6 hours to about 16 hours.

According to aspect (21), there is provided the method of any one of aspects (18) to (20), further comprising ion-exchanging the glass-ceramic.

According to aspect (22), there is provided the method of any one of aspects (18) to (21), wherein the precursor glass-based article comprises: about 55.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 2.0 wt.% to about 20.0 wt.% Al₂O₃(ii) a 0 wt.% to about 5.0 wt.% B₂O₃(ii) a About 5.0 wt.% to about 15.0 wt.% of％Li₂O; 0 wt.% to about 5.0 wt.% Na₂O; 0 wt.% to about 4.0 wt.% K₂O; 0 wt% to about 8.0 wt% MgO; 0 wt% to about 10.0 wt% ZnO; about 0.5 wt% to about 5.0 wt% TiO₂(ii) a About 1.0 wt.% to about 6.0 wt.% P₂O₅(ii) a About 2.0 wt% to about 10.0 wt% ZrO₂(ii) a 0 wt.% to about 0.4 wt.% CeO₂(ii) a About 0.05 wt.% to about 0.5 wt.% SnO + SnO₂(ii) a About 0.1 wt.% to about 5.0 wt.% FeO + Fe₂O₃(ii) a About 0.1 wt% to about 5.0 wt% NiO; about 0.1 wt% to about 5.0 wt% Co₃O₄(ii) a 0 wt% to about 4.0 wt% MnO + MnO₂+Mn₂O₃(ii) a 0 wt% to about 2.0 wt% Cr₂O₃(ii) a 0 wt% to about 2.0 wt% CuO; and 0 wt% to about 2.0 wt% V₂O₅。

According to aspect (23), there is provided the method of any one of aspects (18) to (22), wherein the precursor glass-based article comprises: about 65.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 7.0 wt.% to about 11.0 wt.% Al₂O₃(ii) a About 6.0 wt% to about 11.0 wt% Li₂O; about 2.0 wt% to about 4.0 wt% TiO₂(ii) a About 1.5 wt.% to about 2.5 wt.% P₂O₅(ii) a About 2.0 wt% to about 4.0 wt% ZrO₂(ii) a About 1.0 wt.% to about 4.0 wt.% FeO + Fe₂O₃(ii) a About 0.5 wt% to about 1.5 wt% NiO; and about 0.1 wt% to about 0.4 wt% Co₃O₄。

According to aspect (24), a glass is provided. The glass comprises: about 55.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 2.0 wt.% to about 20.0 wt.% Al₂O₃(ii) a 0 wt.% to about 5.0 wt.% B₂O₃(ii) a About 5.0 wt% to about 15.0 wt% Li₂O; 0 wt.% to about 5.0 wt.% Na₂O; 0 wt.% to about 4.0 wt.% K₂O; 0 wt% to about 8.0 wt% MgO; 0 wt% to about 10.0 wt% ZnO; about 0.5 wt% to about 5.0 wt% TiO₂(ii) a About 1.0 weightAmount% to about 6.0 wt% P₂O₅(ii) a About 2.0 wt% to about 10.0 wt% ZrO₂(ii) a 0 wt.% to about 0.4 wt.% CeO₂(ii) a About 0.05 wt.% to about 0.5 wt.% SnO + SnO₂(ii) a About 0.1 wt.% to about 5.0 wt.% FeO + Fe₂O₃(ii) a About 0.1 wt% to about 5.0 wt% NiO; about 0.1 wt% to about 5.0 wt% Co₃O₄(ii) a 0 wt% to about 4.0 wt% MnO + MnO₂+Mn₂O₃(ii) a 0 wt% to about 2.0 wt% Cr₂O₃(ii) a 0 wt% to about 2.0 wt% CuO; and 0 wt% to about 2.0 wt% V₂O₅。

According to aspect (25), there is provided the glass of aspect (24), comprising: about 65.0 wt.% to about 75.0 wt.% SiO₂(ii) a About 7.0 wt.% to about 11.0 wt.% Al₂O₃(ii) a About 6.0 wt% to about 11.0 wt% Li₂O; about 2.0 wt% to about 4.0 wt% TiO₂(ii) a About 1.5 wt.% to about 2.5 wt.% P₂O₅(ii) a About 2.0 wt% to about 4.0 wt% ZrO₂(ii) a About 1.0 wt.% to about 4.0 wt.% FeO + Fe₂O₃(ii) a About 0.5 wt% to about 1.5 wt% NiO; and about 0.1 wt% to about 0.4 wt% Co₃O₄。

Additional features and advantages will be set forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments as described herein, including the detailed description which follows, the claims, as well as the appended drawings.

It is to be understood that both the foregoing general description and the following detailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated in and constitute a part of this specification. The drawings illustrate various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter.

Drawings

FIG. 1 schematically shows a cross-section of a glass-ceramic having a compressive stress layer on a surface thereof according to embodiments disclosed and described herein;

FIG. 2A is a plan view of an exemplary electronic device incorporating any of the glass-ceramics disclosed herein;

FIG. 2B is a perspective view of the exemplary electronic device of FIG. 2A;

FIG. 3 is a transmission spectrum of a glass-ceramic having a thickness of 0.8mm according to an embodiment and two glass-ceramics having a thickness of 0.8mm according to a comparative example;

FIG. 4 is a Weibull plot of ring-on-ring (RoR) strength test results of a glass-ceramic before and after an ion exchange treatment according to an embodiment;

FIG. 5 is Na of ion exchanged glass-ceramic according to an embodiment₂Graph of O concentration (in wt.%) as a function of depth from the surface, measured by an electronic microprobe;

FIG. 6 is a schematic diagram of a ring on ring test apparatus.

Detailed Description

Reference will now be made in detail to black lithium silicate glass-ceramics according to various embodiments. In particular, black lithium silicate glass ceramics have an aesthetic appearance and exhibit high strength and fracture toughness. Thus, the black lithium silicate glass ceramic is suitable for use as a housing for portable electronic devices.

In the description below, like reference numerals designate similar or corresponding parts throughout the several views shown in the drawings. It is also to be understood that, unless otherwise indicated, terms such as "top," "bottom," "outward," "inward," and the like are words of convenience and are not to be construed as limiting terms. Whenever a group is described as consisting of at least one of a group of elements or a combination thereof, it is understood that the group may consist of any number of those listed elements, either individually or in combination with each other. Unless otherwise indicated, a range of numerical values set forth includes both the upper and lower limits of the range, as well as any range between the stated ranges. As used herein, the indefinite article "a" or "an" and its corresponding definite article "the" mean "at least one" or "one or more", unless otherwise indicated. It is also to be understood that the various features disclosed in the specification and in the drawings may be used in any and all combinations.

All components of the glasses described herein are expressed in weight percent (wt%), and the compositions are on an oxide basis, unless otherwise specified. All temperatures are expressed in degrees Celsius (. degree. C.) unless otherwise noted.

It is noted that the terms "substantially" and "about" may be used herein to represent the degree of inherent uncertainty that may be attributed to any quantitative comparison, value, measurement, or other representation. The terms "comprises," "comprising," and any other variation thereof, are intended to cover a non-exclusive inclusion, such that a non-exclusive inclusion does not imply that all of the features and functions of the subject matter claimed herein are in fact, or even wholly, essential to the subject matter. For example, "substantially free of K₂The glass of O' is one in which K is not actively driven₂O is added or dosed to the glass but may be present in very small amounts as a contaminant, for example, in an amount of less than about 0.01 weight percent. As used herein, when the term "about" is used to modify a numerical value, the particular numerical value is also disclosed.

The glass-ceramic contains a primary crystalline phase, a secondary crystalline phase, and a residual glass phase. The primary crystalline phase is the predominant crystalline phase, defined herein as the crystalline phase that occupies the largest portion of the glass-ceramic by weight. Thus, the secondary crystalline phase is present in a concentration of less than the weight percent of the primary crystalline phase, in weight percent of the glass-ceramic.

In an embodiment, the primary crystalline phase comprises a lithium silicate. The lithium silicate may be a lithium metasilicate or a lithium disilicate. In embodiments, the lithium silicate is the only primary crystalline phase.

In an embodiment, the glass-ceramic comprises a secondary crystalline phase comprising at least one of: petalite, beta-quartz, beta-spodumene, cristobalite, and lithium phosphate. As used herein, β -spodumene may represent a β -spodumene solid solution. In embodiments, the glass-ceramic contains more than one secondary crystalline phase. In some embodiments, additional crystalline phases may be present in the glass-ceramic.

In embodiments, the total crystallinity of the glass-ceramic is sufficiently high to provide enhanced mechanical properties, such as: hardness, young's modulus and scratch resistance. As used herein, the units of total crystallinity provided are weight% and refer to the sum of the weight% of all crystalline phases present in the glass-ceramic. In embodiments, the total crystallinity is greater than or equal to about 50 weight percent, for example: greater than or equal to about 55 wt%, greater than or equal to about 60 wt%, greater than or equal to about 65 wt%, greater than or equal to about 70 wt%, greater than or equal to about 75 wt%, or greater. It should be understood that any of the above ranges may be combined with any other ranges in an embodiment. In embodiments, the total crystallinity of the glass-ceramic is greater than or equal to about 50 wt.% to less than or equal to about 75 wt.%, for example: greater than or equal to about 55 wt% to less than or equal to about 70 wt%, or greater than or equal to about 60 wt% to less than or equal to about 65 wt%, and all ranges and subranges therebetween. The total crystallinity of the glass-ceramic is determined by Rittwald's quantitative analysis of the X-ray diffraction (XRD) results.

The glass-ceramic is opaque or translucent. In embodiments, the glass-ceramic exhibits a transmittance of less than about 10% in the visible spectrum (380nm to 760nm), for example: less than about 9%, less than about 8%, less than about 7%, less than about 6%, less than about 5%, less than about 4%, less than about 3%, less than about 2%, less than about 1%, or less. As used herein, transmittance refers to total transmittance, and is measured using a Perkin Elmer Lambda (Perkin Elmer Lambda)950UV/Vis/NIR spectrophotometer with a 150mm integrating sphere. The sample was mounted at the entrance end of the ball, which allowed collection of the wide angle scattered light, and a reference Spectralon reflector dish was located above the exit end of the ball. The total transmission is generated relative to the open beam baseline measurement.

In an embodiment, the glass-ceramic is black. Glass-ceramics can be characterized by the following color coordinates: l is from 20.0 to 40.0, a is from-1.0 to 0.5, and b is from-5.0 to 1.0. In some embodiments, the glass-ceramic may have a value of L x of 20.0 to 40.0, for example: 21.0 to 39.0, 22.0 to 38.0, 23.0 to 37.0, 24.0 to 36.0, 23.0 to 35.0, 25.0 to 34.0, 26.0 to 33.0, 27.0 to 32.0, 28.0 to 31.0, or 29.0 to 30.0%, and all ranges and subranges therebetween. In some embodiments, the glass-ceramic may have a value of-1.0 to 1.0, for example: -0.9 to 0.9, -0.8 to 0.8, -0.7 to 0.7, -0.6 to 0.6, -0.5 to 0.5, -0.4 to 0.4, -0.3 to 0.3, -0.2 to 0.2, or-0.1 to 0.1, and all ranges and subranges between the above values. In some embodiments, the glass-ceramic may have a b value of-5.0 to 2.0, for example: -4.5 to 1.5, -4.0 to 1.0, -3.5 to 0.5, -3.0 to 0.0, -2.5 to-0.5, -2.0 to-1.0, or-1.5, and all ranges and subranges between the above values. As used herein, color coordinates were measured under SCI UVC conditions using an X-riteCi 7F 02 light source.

In embodiments, the glass-ceramic may have a high fracture toughness. The high fracture toughness is achieved at least in part due to the crystalline phase assemblage of the glass-ceramic. In some embodiments, the glass-ceramic may have a thickness of greater than or equal to about 0.9 MPa-m^0.5To less than or equal to about 2.0 MPa-m^0.5Fracture toughness of (b), for example: greater than or equal to about 1.0 MPa-m^0.5To less than or equal to about 1.9 MPa-m^0.5Greater than or equal to about 1.1 MPa-m^0.5To less than or equal to about 1.8 MPa-m^0.5Greater than or equal to about 1.2 MPa-m^0.5To less than or equal to about 1.7 MPa-m^0.5Greater than or equal to about 1.3 MPa-m^0.5To less than or equal to about 1.6 MPa-m^0.5Greater than or equal to about 1.4 MPa-m^0.5To less than or equal to about 1.5 MPa-m^0.5And all ranges and subranges between the above values. In some embodiments, the glass-ceramic may have a thickness of greater than or equal to about 1.0 MPa-m^0.5To less than or equal to about 1.5 MPa-m^0.5The fracture toughness of (3). Fracture toughness was measured by the Chevron Notched Short Bar (CNSB) method, as described below.

In an embodiment, the glass-ceramic may have high strength. The high strength is achieved at least in part due to the crystalline phase assemblage of the glass-ceramic. In some embodiments, the strength of the glass-ceramic is greater than or equal to about 290MPa, for example: greater than or equal to about 300MPa, greater than or equal to about 310MPa, greater than or equal to about 320MPa, greater than or equal to about 330MPa, greater than or equal to about 340MPa, greater than or equal to about 350MPa, greater than or equal to about 360MPa, greater than or equal to about 370MPa, greater than or equal to about 380MPa, greater than or equal to about 390MPa, or greater. In embodiments, the glass-ceramic has a strength of greater than or equal to about 290MPa to less than or equal to 400MPa, for example: greater than or equal to about 300MPa to less than or equal to about 390MPa, greater than or equal to about 310MPa to less than or equal to about 380MPa, greater than or equal to about 320MPa to less than or equal to about 370MPa, greater than or equal to about 330MPa to less than or equal to about 360MPa, greater than or equal to about 340MPa to less than or equal to about 350MPa, and any and all subranges formed by these endpoints. Strength refers to the strength measured by the ring-on-ring test described below.

The composition of the lithium silicate glass-ceramic will now be described. In the embodiments of the glass-ceramics described herein, the constituent components (e.g., SiO) are not otherwise specified₂、Al₂O₃、LiO₂And Na₂O, etc.) is based on the weight percent (wt%) of the oxide. The components of the glass-ceramic according to embodiments are discussed independently below. It is to be understood that any of the various stated ranges for one component may be combined individually with any of the various stated ranges for any of the other components.

In embodiments of the glass-ceramics disclosed herein, SiO₂Is the largest component. SiO 2₂As the main network former and stabilizes the network structure. SiO 2₂Is necessary to form the desired lithium silicate crystalline phase. Pure SiO₂Has a low CTE and is alkali free. However, pure SiO₂Has a high melting point. Thus, if SiO is present in the glass-ceramic₂Too high a concentration of (b) may result in a decrease in formability of the precursor glass composition used to form the glass-ceramic due to the higher SiO₂The concentration increases the difficulty of melting the glass, which in turn negatively affects the formability of the precursor glass. In embodiments, the glass composition comprises SiO₂The amount of (a) is generally greater than or equal to about 55.0 wt%, for example: greater than or equal to about 56.0 wt%, greater than or equal to about 57.0 wt%, greater than or equal to about 58.0 wt%, greater than or equal to about 59.0 wt%, greater than or equal to about 60.0 wt%, greater than or equal to about 61.0 wt%, greater than or equal to about 62.0 wt%, greater than or equal to about 63.0 wt%, greater than or equal to about 64.0 wt%, greater than or equal to about 65.0 wt%, greater than or equal to about 66.0 wt%, greater than or equal to about 67.0 wt%, greater than or equal to about 68.0 wt%, greater than or equal to about 69.0 wt%, greater than or equal to about 70.0 wt%, greater than or equal to about 71.0 wt%, greater than or equal to about 72.0 wt%, greater than or equal to about 73.0 wt%, or greater than or equal to about 74.0 wt%. In embodiments, the glass composition comprises SiO₂In an amount less than or equal to about 75.0 wt%, for example: less than or equal to about 74.0 wt%, less than or equal to about 73.0 wt%, less than or equal to about 72.0 wt%, or less than or equal to about 71.0 wt%, less than or equal to about 70.0 wt%, less than or equal to about 69.0 wt%, less than or equal to about 68.0 wt%, less than or equal to about 67.0 wt%, less than or equal to about 66.0 wt%, less than or equal to about 65.0 wt%, less than or equal to about 64.0 wt%, less than or equal to about 63.0 wt%, less than or equal to about 62.0 wt%, less than or equal to about 61.0 wt%, less than or equal to about 60.0 wt%, less than or equal to about 59.0 wt%, less than or equal to about 58.0 wt%, less than or equal to about 57.0 wt%, or less than or equal to about 56.0 wt%. It should be understood that any of the above ranges may be combined with any other ranges in an embodiment. In embodiments, the glass composition comprises SiO₂The amount of (a) is greater than or equal to about 55.0 wt% to less than or equal to about 75.0 wt%, for example: greater than or equal to about 56.0 wt% to less than or equal to about 74.0 wt%, greater than or equal to about 57.0 wt% to less than or equal to about 73.0 wt%, greater than or equal to about 58 wt%, and0 wt% to less than or equal to about 72.0 wt%, greater than or equal to about 59.0 wt% to less than or equal to about 71.0 wt%, greater than or equal to about 60.0 wt% to less than or equal to about 70.0 wt%, greater than or equal to about 61.0 wt% to less than or equal to about 69.0 wt%, greater than or equal to about 62.0 wt% to less than or equal to about 68.0 wt%, greater than or equal to about 63.0 wt% to less than or equal to about 67.0 wt%, greater than or equal to about 64.0 wt% to less than or equal to about 66.0 wt%, or about 65.0 wt%, as well as all ranges and subranges between the foregoing values. In some embodiments, the glass-ceramic comprises SiO₂In an amount of greater than or equal to about 65 wt% to less than or equal to about 75 wt%.