Glass-ceramics toughened with zirconia

Abstract

Glass-ceramics toughened via Zr02have high molar fractions of tetragonal Zr02and fracture toughness values greater than 1.8 MPa-m 1 / 2 The glass-ceramics can also include other minor phases, including lithium silicate, which can be beneficial for toughening or strengthening via an ion exchange process. Additional second phases can also reduce the coefficient of thermal expansion of the glass-ceramics. Methods of making such glass-ceramics are also provided.

Description

[0001] This application is a divisional application of the invention patent application filed on June 26, 2017, with application number 201780046133.4 and invention title "Zirconium Oxide Toughened Glass Ceramics". Technical Field

[0002] This application claims priority to U.S. Provisional Application Serial No. 62 / 512,418, filed May 30, 2017; U.S. Provisional Application Serial No. 62 / 361,210, filed July 12, 2016; and U.S. Provisional Application Serial No. 62 / 354,271, filed June 24, 2016, the contents of which form the basis of this document and are incorporated herein by reference in their entirety.

[0003] This disclosure relates to glass and glass-ceramics. More specifically, this disclosure relates to glass-ceramics—glasses containing tetragonal zirconia together forming said glass-ceramics. More specifically, this disclosure relates to glass-ceramics—containing tetragonal zirconia having high fracture toughness. background

[0004] Transformed and toughened ZrO2 ceramics are among the toughest and strongest engineering ceramics, and are typically produced via ceramic processing techniques such as hot pressing or sintering. In another approach, pre-formed ZrO2 particles are dispersed within a ceramic or glass matrix. In this case, the ZrO2 content of the final product is substantially lower than that of pure ceramic materials. Typically, these ceramics are generally monolithically stabilized oxides, such as ZrO2 stabilized with Ca, Mg, Ce, or yttrium oxide, where the monolithic main phase is ZrO2.

[0005] To achieve transformation toughening, it is necessary to obtain tetragonal ZrO2 in the as-made portion. The tetragonal ZrO2 phase transforms to a monoclinic phase under mechanical stress, resulting in toughening. However, ZrO2 undergoes a thermal transformation from a tetragonal symmetry or structure to a monoclinic symmetry or structure at approximately 950 °C. This can occur during material processing, resulting in a material containing a "transformed" monoclinic crystal form. The presence of the monoclinic crystal form in the as-made material does not provide an opportunity for subsequent transformation toughening. Summary of the Invention

[0006] This disclosure provides a ZrO2-toughened glass-ceramic having a high molar fraction of tetragonal ZrO2 and a strength greater than 2 MPa·m. 1 / 2 The glass-ceramic exhibits good fracture toughness. It may also include other secondary phases that can contribute to toughening or strengthening. In some embodiments, strengthening may be achieved via an ion exchange process. Additional phases may also impart other properties or characteristics to the glass-ceramic, such as reducing its coefficient of thermal expansion. Methods for manufacturing such glass-ceramics are also provided.

[0007] In aspect (1), this disclosure provides a glass-ceramic comprising at least two crystalline phases, the first crystalline phase comprising a ZrO2 phase and the second crystalline phase comprising a lithium silicate phase, the glass-ceramic further comprising a residual glass phase, thereby obtaining a glass-ceramic having a strength from 1.8 MPa·m 1 / 2 Up to 10 MPa·m 1 / 2 Improved fracture toughness, as measured by the herringbone notch short bar method.

[0008] In another aspect (2), this disclosure provides a glass-ceramic of aspect (1), wherein the first crystalline phase is a tetragonal ZrO2 phase. In aspect (3), this disclosure provides a glass-ceramic of aspect (1) or (2), wherein the second crystalline phase is a lithium disilicate phase. In aspect (4), this disclosure provides a glass-ceramic of any of aspects (1)-(3) comprising the following composition: 50-80 mol% SiO2; 18-40 mol% Li2O; 1.5-25 mol% ZrO2; and greater than 0-5 mol% P2O5.

[0009] In aspect (5), this disclosure provides a glass-ceramic of any of aspects (1)-(4), wherein the at least two crystalline phases constitute a weight percentage (wt%) of the total glass-ceramic, measured as (((weight of the at least two crystalline phases) / (total weight of the glass-ceramic)) * 100), and wherein the at least two crystalline phases constitute 30-98 wt% of the total glass-ceramic. In aspect (6), this disclosure provides a glass-ceramic of any of aspects (1)-(5), wherein the at least two crystalline phases constitute 60-95 wt% of the total glass-ceramic. In aspect (7), this disclosure provides a glass-ceramic of any of aspects (1)-(6), wherein tetragonal ZrO2 constitutes a weight percentage (wt%) of the total ZrO2 in the glass-ceramic, measured as (((weight of the tetragonal ZrO2) / (total weight of ZrO2 in the glass-ceramic)) * 100), and wherein the tetragonal ZrO2 constitutes 40-95 wt% of the ZrO2 in the glass-ceramic. In aspect (8), this disclosure provides a glass-ceramic of any of aspects (1)-(7), wherein tetragonal ZrO2 constitutes a weight percentage (wt%) of the total glass-ceramic, measured as (((weight of the tetragonal ZrO2) / (total weight of the glass-ceramic))*100), and wherein the tetragonal ZrO2 phase constitutes 5-25 wt% of the total glass-ceramic. In aspect (9), this disclosure provides a glass-ceramic of any of aspects (1)-(8), wherein tetragonal ZrO2 constitutes a weight percentage (wt%) of the total crystalline phase of the glass-ceramic, measured as (((weight of the tetragonal ZrO2) / (total weight of the crystalline phase of the glass-ceramic))*100), and wherein the tetragonal ZrO2 phase constitutes 5-50 wt% of the total crystalline phase of the glass-ceramic.

[0010] In aspect (10), this disclosure provides a glass-ceramic of any one of aspects (1)-(9), wherein the tetragonal ZrO2 crystal has an average crystal size of 0.1 μm to 10 μm along its longest dimension. In aspect (11), this disclosure provides a glass-ceramic of aspect (10), wherein the tetragonal ZrO2 crystal has an average crystal size of 0.3 μm to 7 μm along its longest dimension. In aspect (12), this disclosure provides a glass-ceramic of aspect (11), wherein the tetragonal ZrO2 crystal has an average crystal size of 0.5 μm to 4 μm along its longest dimension.

[0011] In aspect (13), this disclosure provides a glass-ceramic of any of aspects (1)-(12), wherein the lithium disilicate constitutes a weight percentage (wt%) of the total glass-ceramic, measured as (((weight of the lithium disilicate) / (total weight of the glass-ceramic))*100), and wherein the lithium disilicate constitutes 25-60 wt% of the total glass-ceramic composition. In aspect (14), this disclosure provides a glass-ceramic of any of aspects (1)-(13), wherein the lithium disilicate constitutes a weight percentage (wt%) of the total crystalline phase of the glass-ceramic, measured as (((weight of the lithium disilicate) / (total weight of the crystalline phase of the glass-ceramic))*100), and wherein the lithium disilicate phase may constitute 5-50 wt% of the total crystalline phase of the glass-ceramic. In aspect (15), this disclosure provides a glass-ceramic of any of aspects (1)-(14), wherein the lithium disilicate crystals have an average crystal size from 1 μm to 20 μm along their longest dimension. In aspect (16), this disclosure provides a glass-ceramic of aspect (15), wherein the lithium disilicate crystal has an average crystal size of 5 μm to 15 μm along its longest dimension.

[0012] In aspect (17), this disclosure provides a glass-ceramic of any of aspects (1)-(16), which further comprises one or more additional crystalline phases. In aspect (18), this disclosure provides a glass-ceramic of aspect (17), wherein the one or more additional crystalline phases are selected from the group consisting of: lithium aluminosilicate, white silica, β-spodumene, lithium phosphate rock (Li3PO4), lithium orthophosphate, quartz solid solution, zircon, lithium metasilicate (Li2SiO3), monoclinic zirconium oxide, cubic zirconium oxide, or (Na,Li)ZrSi6O 18 Or a combination thereof. In aspect (19), this disclosure provides a glass-ceramic of aspect (18), wherein the one or more additional crystalline phases are selected from the group consisting of: monoclinic ZrO2, lithium aluminosilicate, β-spodumene solid solution, β-quartz solid solution, or α-quartz, or a combination thereof. In aspect (20), this disclosure provides a glass-ceramic of aspect (19), wherein the one or more additional crystalline phases are two or more phases selected from the group consisting of: monoclinic ZrO2 and at least one of lithium aluminosilicate, β-spodumene solid solution, β-quartz solid solution, or α-quartz, wherein the monoclinic ZrO2 is >0-5 wt% of the glass-ceramic.

[0013] In aspect (21), this disclosure provides a glass-ceramic of any of aspects (1)-(20), further comprising: 0-5 mol% Al2O3 and 0-5 mol% Na2O. In aspect (22), this disclosure provides a glass-ceramic of any of aspects (1)-(21), further comprising: 0-14 mol% R2O; 0-10 mol% MO; 0-5 mol% TMO; and 0-5 mol% REO. In aspect (23), this disclosure provides a glass-ceramic of any of aspects (1)-(22), comprising: 55-70 mol% SiO2; 18-30 mol% Li2O; 4-20 mol% ZrO2; and 0.2-5 mol% P2O5. In aspect (24), this disclosure provides a glass ceramic of any of aspects (1)-(23) comprising: 58-69 mol% SiO2; 25-36 mol% Li2O; 6-15 mol% ZrO2; >0-5 mol% Al2O3; 0-5 mol% B2O3; 0.2-3 mol% P2O5; 0-8 mol% MO; 0-5 mol% TMO; and 0-5 mol% REO. In aspect (25), this disclosure provides a glass ceramic of any of aspects (1)-(24) further comprising >0-5 mol% REO. In aspect (26), this disclosure provides a glass ceramic of aspect (25), wherein the REO comprises Y2O3 and Y2O3 (mol%) / ZO2 (mol%) < 0.2. In aspect (27), this disclosure provides a glass-ceramic of any of aspects (1)-(26), wherein the glass-ceramic is free of Rb2O and Cs2O. In aspect (28), this disclosure provides a glass-ceramic of any of aspects (1)-(27), further comprising >0-5 mol% TiO2. In aspect (29), this disclosure provides a glass-ceramic of any of aspects (1)-(28), further comprising >0-3 mol% ZnO.

[0014] In aspect (30), this disclosure provides a glass ceramic of any of aspects (1)-(29), further comprising >0-4 mol% of a color component. In aspect (31), this disclosure provides a glass ceramic of aspect (30), wherein the color component comprises Fe2O3, V2O5, Cr2O3, MnO2, NiO, CuO, Co3O4, and combinations thereof. In aspect (32), this disclosure provides a glass ceramic of any of aspects (1)-(31), wherein the glass ceramic exhibits a color in the following CIELAB color space coordinates: a* = about -1 to about +3; b* = about -7 to about +3; and L* > 85. In aspect (33), this disclosure provides a glass ceramic of any of aspects (1)-(32), wherein a* = about -1 to about 0; b* = about -2 to about 0; and L* > 88. In aspect (34), this disclosure provides a glass ceramic of any of aspects (1)-(31), wherein the glass ceramic exhibits a color in the following CIELAB color space coordinates: a* = about -1 to about 1; b* = about -4 to about 1; and L* < 60. In aspect (35), this disclosure provides a glass ceramic of aspect (34), wherein a* = about -1 to about 1; b* = about -1 to about 1; and L* < 40. In aspect (36), this disclosure provides a glass ceramic of any of aspects (1)-(35), wherein the glass ceramic has a color depth of 2 MPa·m 1 / 2 Up to 10 MPa·m 1 / 2 The fracture toughness, as measured by the herringbone notch short bar method. In aspect (37), this disclosure provides a glass-ceramic of any of aspects (1)-(36), wherein the glass-ceramic further comprises an ion exchange layer having a compression depth of at least 10 μm. In aspect (38), this disclosure provides a glass-ceramic of aspect (37), wherein the ion exchange layer has a compression depth of at least 30 μm. In aspect (39), this disclosure provides a glass-ceramic of aspect (37) or (38), wherein the surface compression of the glass-ceramic is from 350 MPa to 800 MPa.

[0015] In aspect (40), this disclosure provides an article comprising a glass-ceramic from any of aspects (1)-(39). In aspect (41), this disclosure provides an article of aspect (40), wherein the article comprises a portion of a housing for a consumer electronic device, the consumer electronic device comprising the housing and electrical components at least partially provided within the housing. In aspect (42), this disclosure provides an article of aspect (40), wherein the glass-ceramic forms at least a portion of a dental compound, dental filling, or dental article. In aspect (43), this disclosure provides an article of aspect (42), wherein the dental article is one of the following: a filling, a bridge, a splint, a crown, a portion of a crown, a denture, a tooth, a clip, an inlay, a crown body, a fabric, a panel, a facet, an implant, a cylinder, a bridge abutment, or a connector.

[0016] In aspect (44), this disclosure provides a method for manufacturing a glass ceramic according to any of aspects (1)-(39), the method comprising the steps of: a. providing a precursor glass material comprising SiO2, Li2O, ZrO2 and P2O5; b. ceramizing the precursor material to form the glass ceramic, wherein ceramization comprises heating the precursor material at a first temperature for a first period of about 15 minutes to about 3 hours, followed by heating to a second temperature for a second period of about 0.5 hours to 5 hours, wherein the first temperature is in the range of about 600°C to about 850°C and the second temperature is in the range of about 725°C to about 1000°C.

[0017] In aspect (45), this disclosure provides a method for manufacturing glass-ceramics according to aspect (44), wherein the precursor glass material comprises: 50-80 mol% SiO2; 18-40 mol% Li2O; 3-25 mol% ZrO2; and greater than 0-5 mol% P2O5. In aspect (46), this disclosure provides a method for manufacturing glass-ceramics according to aspect (45), wherein the precursor material further comprises: 0-5 mol% Al2O3 and 0-5 mol% Na2O. In aspect (47), this disclosure provides a method for manufacturing glass-ceramics according to aspect (45) or (46), wherein the precursor material further comprises: 0-14 mol% R2O; 0-10 mol% MO; 0-5 mol% TMO; and 0-5 mol% REO. In aspect (48), this disclosure provides a method for manufacturing glass-ceramics according to any of aspects (44)-(47), wherein the precursor material comprises: 55-70 mol% SiO2; 18-30 mol% Li2O; 4-20 mol% ZrO2; and 0.2-5 mol% P2O5. In aspect (49), this disclosure provides a method for manufacturing glass-ceramics according to any of aspects (44)-(48), wherein the precursor material comprises: 58-69 mol% SiO2; 25-36 mol% Li2O; 6-15 mol% ZrO2; >0-5 mol% Al2O3; 0-5 mol% B2O3; 0.2-3 mol% P2O5; 0-8 mol% MO; 0-5 mol% TMO; and 0-5 mol% REO.

[0018] In aspect (50), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(49), wherein the precursor material further comprises: >0-5 mol% REO. In aspect (51), this disclosure provides a method for manufacturing glass ceramics according to aspect (50), wherein the REO comprises Y2O3 or CeO2. In aspect (52), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(51), wherein the precursor material does not contain Rb2O and Cs2O. In aspect (53), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(52), wherein the precursor material further comprises: >0-5 mol% TiO2. In aspect (54), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(53), wherein the precursor material further comprises: >0-3 mol% ZnO. In aspect (55), this disclosure provides a method for manufacturing glass-ceramics according to any of aspects (44)-(54), wherein the precursor material further comprises: >0-4 mol% of a color component. In aspect (56), this disclosure provides a method for manufacturing glass-ceramics according to any of aspects (44)-(55), wherein the color component comprises Fe2O3, V2O5, Cr2O3, MnO2, NiO, CuO, NiO, Co3O4, and combinations thereof.

[0019] In aspect (57), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(56), wherein the first time period is from about 15 minutes to about 1 hour. In aspect (58), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(57), wherein the second time period is from about 0.5 hours to about 2 hours. In aspect (59), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(58), wherein the precursor material comprises a precursor glass. In aspect (60), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(59), wherein the precursor material further comprises grinding the precursor glass into precursor glass powder. In aspect (61), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(60), which further comprises the steps of sintering and ceramizing the precursor glass powder. In aspect (62), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(61), further comprising: sintering the glass ceramic. In aspect (63), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(62), further comprising: hot pressing the glass ceramic. In aspect (64), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(63), further comprising: machining or shaping the glass precursor material before heating the precursor material at a first temperature. In aspect (65), this disclosure provides a method for manufacturing glass ceramics according to any of aspects (44)-(64), further comprising: machining or shaping the glass precursor material after heating the precursor material at the first temperature and before heating the precursor material at a second temperature.

[0020] In aspect (66), this disclosure provides a glass ceramic of any of aspects (1)-(43) which can be produced by the following process: a. providing a precursor material comprising SiO2, Li2O, ZrO2 and P2O5; b. ceramizing the precursor material to form the glass ceramic, wherein ceramization comprises heating the precursor material at a first temperature for a first period of about 15 minutes to about 3 hours, followed by heating to a second temperature for a second period of about 0.5 hours to 5 hours, wherein the first temperature is in the range of about 600°C to about 850°C and the second temperature is in the range of about 725°C to about 1000°C.

[0021] In aspect (67), this disclosure provides a glass-ceramic of aspect (66), wherein the precursor glass material comprises: 50-80 mol% SiO2; 18-40 mol% Li2O; 3-25 mol% ZrO2; and greater than 0-5 mol% P2O5.

[0022] These and other aspects, advantages and distinguishing features will become apparent from the following embodiments, the accompanying drawings and the appended claims. Attached Figure Description

[0023] Referring generally to the accompanying drawings, it should be understood that the illustrations are for the purpose of describing particular embodiments and are not intended to limit the scope of this disclosure or the appended claims. The drawings are not necessarily drawn to scale, and for clarity and simplicity, certain features and views may be exaggerated in scale or shown schematically.

[0024] Figure 1A It is a scanning electron microscopy (SEM) image of a glass-ceramic material, which is ceramized by heating at 750°C for 2 hours and then at 900°C for 4 hours;

[0025] Figure 1B The image shows a SEM image of a glass-ceramic material that has been ceramicized by heating at 800°C for 2 hours and then at 900°C for 4 hours.

[0026] Figures 2A-2D These are SEM images showing the indentation of Example 8 after a 50 kgf Vickers indentation. The exemplary composition was ceramized at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours. The tortuous crack path and crack deflection via lithium disilicate and tetragonal zirconia are visible in the example;

[0027] Figures 3A-3D The SEM image of Example 8 (Example 8) Figure 3A ), along with some components of Example 8, SEM element mapping, where Figure 3B Showing silicon present in the material, Figure 3C Zirconia is displayed, and Figure 3D Phosphorus is displayed.

[0028] Figures 4A-4D The accompanying figures show the X-ray diffraction spectra of the phase combinations of the implemented glass-ceramic. The figures also show that lithium disilicate (LS2) and tetragonal ZrO2 (t-ZrO2) are present in various embodiments along with many other phases (lithium metasilicate (LMS), monoclinic ZrO2 (m-ZrO2)). Figure 4A This demonstrates the phase combination of Example 8. Figure 4BFor the phase combination of Example 14, Figure 4C For example, the phase combination of 40, and Figure 4D This is the phase combination of Example 44. All examples were ceramized at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours, except for Example 44, which was ceramized at 750°C for 2 hours, followed by ceramization at 850°C for 4 hours.

[0029] Figure 5 This is data on abraded ring-on-ring (ARoR) obtained from 0.8 mm thick samples of non-ion-exchanged and ion-exchanged ZrO2-toughened glass-ceramics (Example 8), which were ion-exchanged for many different times and temperatures.

[0030] Figure 6A and 6B This is a comparison of the drop performance of the exemplary embodiment (Example 14) and ZrO2 ceramic. All parts were 0.8 mm thick, dropped onto 180-grit sandpaper and subsequently preserved on 30-grit sandpaper. Example 14 was ceramicized at 750°C for 2 hours, followed by ceramicization at 875°C for 4 hours; Comp 1 is a reference transparent glass ceramic; CoorsTek TTZ is MgO-stabilized ZrO2 ceramic.

[0031] Figure 7 Example 8 illustrates the loss tangent of a comparison between a reference glass and a reference glass ceramic. The exemplary composition was ceramicized at 750°C for 2 hours, followed by ceramicization at 875°C for 4 hours.

[0032] Figure 8 Example 8 illustrates the dielectric constants of a reference glass and a reference glass ceramic. The exemplary composition was ceramicized at 750°C for 2 hours, followed by ceramicization at 875°C for 4 hours.

[0033] Figures 9A-9C Micrographs of scratch tests performed using a Knoop tip on Example 8 under loads of 14 N and 16 N. The exemplary composition was ceramized at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours. Detailed Implementation

[0034] In the following description, the same element symbols consistently designate the same or corresponding parts in the various views shown in the accompanying drawings. It should also be understood that, unless otherwise specified, terms such as “top,” “bottom,” “outward,” “inward,” and similar expressions are convenience terms and should not be construed as limiting terms. Furthermore, whenever a group is described as comprising at least one of a set of elements or combinations thereof, it should be understood that the group may comprise any number of those listed elements, substantially composed of or consisting of those elements, whether those elements are individual or combined with each other. Similarly, whenever a group is described as comprising at least one of a set of elements or combinations thereof, it should be understood that the group may comprise any number of those listed elements, whether those elements are individual or combined with each other. Unless otherwise specified, in enumeration, the range of values ​​includes the upper and lower limits of the range, and any range between the upper and lower limits. Unless otherwise specified, as used herein, the indefinite article “a / an” and the corresponding definite article “the” mean “at least one” or “one or more”. It should also be understood that the various features disclosed in this specification and in the accompanying drawings can be used in any and all combinations.

[0035] Where ranges of numerical values ​​(including upper and lower limits) are described herein, unless otherwise specified in the specific context, the range is intended to include its endpoints and all integers and fractions within the range. The scope of the claims is not intended to be limited to the specific values ​​stated when the range is defined. Furthermore, when a quantity, concentration, or other value or parameter is given as a range, one or more preferred ranges, or a list of upper and lower preferred values, this should be understood as explicitly disclosing all ranges formed by any pair of any upper or lower extreme or preferred values ​​and any lower or higher extreme or preferred values, regardless of whether the pair is disclosed individually. Finally, when the term “about” is used to describe a value or endpoint of a range, this disclosure should be understood to include the specific value or endpoint mentioned. When the endpoint of a numerical value or range is not stated as “about,” the endpoint of the numerical value or range is intended to include two embodiments: embodiments modified by “about” and embodiments not modified by “about.”

[0036] As used herein, the term “about” means that a quantity, size, composition, parameter, and other quantity and characteristic is not and need not be exact, but may be an approximation and / or larger or smaller, as needed, reflecting tolerances, conversion factors, rounding, measurement errors, and other factors known to those skilled in the art. It should be noted that the term “substantially” may be used herein to indicate the inherent uncertainty attributable to any quantitative comparison, value, measurement, or other representation. These terms are also used herein to indicate the extent to which a quantitative representation may vary from the stated reference value without altering the essential function of the object under discussion. Thus, “Al2O3-free” glass is glass in which Al2O3 is not actively added to or incorporated into the glass, but may be present as a contaminant in extremely small amounts (e.g., 500, 400, 300, 200, or 100 parts per million (ppm) or less).

[0037] Unless otherwise specified, all compositions are expressed as mole percentages (mol%). Unless otherwise specified, the composition range of crystalline materials in glass-ceramics is expressed as weight percentages (wt%). The coefficients of thermal expansion (CTE) are expressed in terms of 10⁻⁶. -7 / ℃ represents, and unless otherwise specified, a value measured over a temperature range of about 20℃ to about 300℃. (g / cm³) 3 The density is expressed as measured by the Archimedes method (ASTM C693).

[0038] The Vickers crack initiation threshold described herein was determined by applying and subsequently removing the indentation load to the glass surface at a rate of 0.2 mm / min. A standard 136° cone angle was used on the indenter, mounted on a diamond indenter. The maximum indentation load was held for 10 seconds. The indentation crack initiation threshold was defined at the indentation load at which at least 50% of the 10 indentations exhibited at least one radial / median crack emanating from the corner of the indentation. The maximum load was increased until the threshold for a given glass-ceramic and / or precursor glass was met. All indentation measurements were performed at room temperature with 50% relative humidity.

[0039] The fracture toughness values ​​described herein are measured using the herringbone-notched short bar method, as known in this technique and described in ASTM Procedure E1304-97 (2014), entitled "Standard Test Method for Plane-Strain (Chevron-Notch) Fracture Toughness of Metallic Materials." The contents of ASTM E1304-97 (2014) are incorporated herein by reference in their entirety. The test method involves applying a load to the notch of a herringbone-notched specimen to induce an opening displacement of the notch. The fracture toughness measured according to this method is relative to a slowly advancing steady-state crack that initiates at the herringbone notch and propagates within the herringbone-shaped band.

[0040] Glass ceramics and glass ceramic precursors

[0041] When glass is transformed into a glass-ceramic, a portion of the glass crystallizes while other portions may remain in a residual glassy phase (e.g., amorphous, non-crystalline). As used herein, the term "glass-ceramic" refers to a material comprising at least one crystalline phase and at least one residual glassy phase. The amount of material in one or more crystalline phases is measured in wt%. The weight fraction ratio of the crystalline phase can be determined by methods known in the art, such as X-ray diffraction including Ritwald refining. In some embodiments, a glass-ceramic is a material comprising at least 30%, 50%, 60%, 70%, 75%, 80%, 85%, 90%, 95%, 97%, 98%, 99%, or greater than 99% w / w of at least one crystalline phase, with the remaining volume comprising a glassy phase. In some embodiments, the material comprises 50-98%, 60-98%, 70-98%, 80-98%, 80-95%, or 60-90% glass-ceramic phase. The term "glassceramic article / glass ceramic articles" is used in its broadest sense to include any object that is wholly or partially made of glass ceramics. As used herein, the term "ceramic" refers to the heat treatment (or multiple heat treatments) or other processes used to transform a precursor glass into a glass ceramic.

[0042] The glass-ceramics described herein include crystalline structures that can be understood through crystallography and known crystal systems. As used herein, the terms "tetragonal ZrO2," "tetragonal zirconia," and "t-ZrO2" are used interchangeably and refer to crystalline ZrO2 having a tetragonal crystal system; the terms "monoclinic ZrO2," "monoclinic zirconia," and "m-ZrO2" are used interchangeably and refer to crystalline ZrO2 having a monoclinic crystal system; and the term "cubic ZrO2" is used interchangeably and refers to crystalline ZrO2 having a cubic crystal system as understood in chemical crystallography. The "lithium silicate" phase may include lithium disilicate, lithium monosilicate, and lithium metasilicate. Additional crystalline structures may exist in the precursor glass or glass-ceramic phase of the material. For example, the lithium disilicate glass-ceramic phase may have an orthorhombic crystal system or other crystal systems.

[0043] The first aspect comprises a zirconia-containing precursor glass and a glass-ceramic made from said precursor glass. The glass-ceramic made from these zirconia-containing precursor glasses is a zirconia-toughened glass-ceramic with a high weight fraction of tetragonal ZrO2. While not by theoretical constraint, it is believed that a high content of tetragonal ZrO2 allows the glass-ceramic to undergo a phase transformation from tetragonal ZrO2 to monoclinic ZrO2, thereby significantly improving the fracture toughness of the material. Support for this theory is the fact that an increased amount of monoclinic ZrO2 is visible in the ground powders made from these materials. In some embodiments, the zirconia-containing glass-ceramic may also contain a lithium silicate phase. In some embodiments, the zirconia phase is tetragonal zirconia and the lithium silicate phase is lithium disilicate.

[0044] The precursor glass is capable of dissolving a significant amount (typically greater than about 10 wt%) of ZrO2 without crystallizing upon cooling from the glass pour. Lithium silicate and / or magnesium silicate melts, with a relatively low alumina content generally exhibiting high ZrO2 solubility. When the precursor glass undergoes a specified heat treatment, the dissolved ZrO2 crystallizes and precipitates primarily as a tetragonal ZrO2 phase, with less than 5 wt% monoclinic ZrO2 relative to the total ZrO2 in some embodiments.

[0045] The glass-ceramics described in this article include a tetragonal ZrO2 phase, a crystalline lithium disilicate (Li2Si2O5) phase, a lithium aluminosilicate phase as needed, and a residual glass phase. Figure 1A and 1BExemplary micrographs of the implemented glass-ceramic are provided, the glass-ceramic comprising a tetragonal ZrO2 phase and a crystalline lithium disilicate (Li2Si2O5) phase. In some embodiments, the tetragonal ZrO2 phase may constitute a significant portion (40-95 wt%, 40-90 wt%, or 50-80 wt%) of ZrO2 present in the glass-ceramic. In some embodiments, the tetragonal ZrO2 phase may constitute 5-25 wt% (([weight of tetragonal ZrO2] / [weight of glass-ceramic])*100) of the total glass-ceramic composition. In some embodiments, the tetragonal ZrO2 phase may constitute 5-60 wt%, 5-50 wt%, 5-40 wt%, 5-30 wt%, or 10-35 wt% (([weight of tetragonal ZrO2] / [weight of all crystalline phases])*100) of the total crystalline phase of the glass-ceramic. In some embodiments, the tetragonal ZrO2 phase may be dispersed throughout the residual glass phase. In other embodiments, the crystalline t-ZrO2 phase "adorns" or is close to or in contact with the lithium disilicate phase, such that the t-ZrO2 and lithium disilicate phases can interact synergistically to provide improved material properties. In some embodiments, the average crystal size along the longest dimension of the tetragonal ZrO2 crystals is 0.1 μm to 10 μm, 0.3 μm to 7 μm, 0.5 μm to 4 μm, 0.8 μm to 3 μm, or 0.5 μm to 3 μm.

[0046] The glass-ceramic further comprises a lithium disilicate phase. In some embodiments, the lithium disilicate phase constitutes about 25 wt% to about 60 wt% of the total glass-ceramic composition. In some embodiments, the tetragonal ZrO2 phase and the lithium disilicate phase constitute 60-95 wt% of the total glass-ceramic. In some embodiments, the lithium disilicate phase may constitute 5-50 wt% of the total crystalline phase of the glass-ceramic. The lithium disilicate crystals may have a lamellar structure, wherein the aspect ratio is about 1.5:1 to 12:1, 2:1 to 8:1, or greater than 2:1. In some embodiments, the average crystal size along the longest dimension of the lithium disilicate crystals is at least 2 μm, 5 μm, 8 μm, or 10 μm, or 1 to 20 μm, 2 to 15 μm, 5 to 20 μm, 5 to 15 μm, 5 to 12 μm, 2 to 12 μm, 1 to 12 μm, 8 to 20 μm, or 10 to 20 μm.

[0047] In some embodiments, the glass-ceramic further comprises one or more additional phases, such as lithium metasilicate, cubic zirconia, monoclinic ZrO2, lithium aluminosilicate, β-spodumene solid solution, β-quartz solid solution, white silica, lithium phosphate rock, zekzerite, quartz solid solution, zircon, lithium orthophosphate, (Na,Li)ZrSi6O 18Or α-quartz phase or a combination thereof. In some embodiments, the additional phases constitute about 0-25 wt% of the glass-ceramic.

[0048] In some embodiments, the glass phase may constitute 1-50 wt%, 2-50 wt%, 3-50 wt%, 5-40 wt%, 5-30 wt%, 5-20 wt%, 3-10 wt%, or 5-50 wt% of the total glass-ceramic composition.

[0049] In some embodiments, the tetragonal ZrO2 / lithium disilicate glass-ceramic and / or the precursor glass used to form the glass-ceramic comprises at least 3 mol% ZrO2 and 18 mol% to 40 mol% Li2O, 19 mol% to 37 mol% Li2O, 25 mol% to 35 mol% Li2O, or 30 mol% to 35 mol% Li2O. In some embodiments, the glass-ceramic and / or the precursor glass used to form the glass-ceramic may comprise additional components. In some embodiments, the mixture further comprises 0 to 7 mol% Al2O3, 0 to 5 mol% Al2O3, 0 to 4 mol% Al2O3, 0 to 3 mol% Al2O3, >0 to 7 mol% Al2O3, >0 to 5 mol% Al2O3, >0 to 4 mol% Al2O3, >0 to 3 mol% Al2O3, 0.5 to 7 mol% Al2O3, 0.5 to 5 mol% Al2O3, 0.5 to 4 mol% Al2O3, or 0.5 to 3 mol% Al2O3.

[0050] In some embodiments, the glass-ceramic may further comprise at least one of a crystalline cubic ZrO2 phase or a monoclinic ZrO2 phase. In some embodiments, the glass-ceramic may comprise a monoclinic ZrO2 phase. In this case, the weight fraction (or weight percentage) of tetragonal zirconia to the weight fraction (or weight percentage) of monoclinic zirconia is at least about 8:1 (i.e., tetragonal ZrO2 (wt%) / monoclinic ZrO2 (wt%) ≥ 8); in some embodiments, at least about 10:1 (tetragonal ZrO2 (wt%) / monoclinic ZrO2 (wt%) ≥ 10); in other embodiments, at least about 15 (tetragonal ZrO2 (wt%) / monoclinic ZrO2 (wt%) ≥ 15); and in other embodiments, at least about 20 (tetragonal ZrO2 (wt%) / monoclinic ZrO2 (wt%) ≥ 20). In some embodiments, the amount of monoclinic ZrO2 in the glass-ceramic is 0 to 5 wt%, >0 to 5 wt%, 0 to 3 wt%, 0 to 1 wt%, >0 to 3 wt%, or >0 to 1 wt%. The weight fraction ratio of the tetragonal zirconia phase to the monoclinic zirconia phase can be determined by X-ray diffraction methods known in this art, such as Rietwald refining.

[0051] In some embodiments, the glass ceramic and / or the precursor glass used to form the glass ceramic comprises SiO2, Li2O, ZrO2, and, if desired, Al2O3, alkali metal oxides, alkaline earth metal oxides, and rare earth oxides. For example, an embodiment may contain 50 mol% to 75 mol% SiO2 (50 mol% ≤ SiO2 ≤ 75 mol%); 18 mol% to 40 mol% Li2O (18 mol% ≤ Li2O ≤ 40 mol% Li2O); 3 mol% to 17 mol% ZrO2 (3 mol% ≤ ZrO2 ≤ 15 mol%); 0 mol% to 5 mol% Al2O3 (0 mol% ≤ Al2O3 ≤ 5 mol%); 0 mol% to 5 mol% Na2O (0 mol% ≤ Na2O ≤ 5 mol%); greater than 0 mol% to 14 mol% R2O (0 mol% < R2O ≤ 14 mol%), where R is the sum of alkali metals Na, K, and Cs (non-Li); and 0 mol% to 5 mol% of at least one alkaline earth metal oxide (RO; R =Mg, Sr, Ca, Ba) (0 mol% RO ≤ 5 mol%); 0 mol% to 5 mol% of at least one transition metal oxide (“TMO”) (oxides of metals of Groups IVB-VIII, IB, and IIB, or Groups 4-12 of the periodic table; e.g., Zn, Ti, Fe, etc.) (0 mol% ≤ RO ≤ 5 mol%); and 0 mol% to 5 mol% of at least one rare earth oxide (“REO”) (oxides of scandium, yttrium, and lanthanides) (0 mol% ≤ REO ≤ 5 mol%). Further aspects of the various components that may constitute the implemented composition are detailed below.

[0052] SiO2, along with Al2O3, B2O3, P2O5, ZrO2, and SnO2, forms a network structure when present in glass-ceramic and / or precursor glasses. SiO2, as the largest oxide component of the glass-ceramic and / or precursor glass, may be included to provide high-temperature stability and chemical stability. In some embodiments, the glass-ceramic and / or precursor glass may contain 50 mol% to 75 mol% SiO2. In some embodiments, the glass-ceramic and / or precursor glass may contain 55 mol% to 70 mol% SiO2. In some embodiments, the glass-ceramic and / or precursor glass may contain 57 mol% to 65 mol% SiO2. In some embodiments, the glass-ceramic and / or precursor glass may contain 57 mol% to 70 mol% SiO2. In some embodiments, the glass ceramic and / or precursor glass may contain 50 mol% to 75 mol%, 50 mol% to 70 mol%, 50 mol% to 65 mol%, 50 mol% to 60 mol%, 55 mol% to 75 mol%, 57 mol% to 70 mol%, 57 mol% to 65 mol%, 55 mol% to 70 mol%, or 55 mol% to 65 mol% SiO2. In some embodiments, the glass-ceramic and / or precursor glass comprises 50 mol%, 51 mol%, 52 mol%, 53 mol%, 54 mol%, 55 mol%, 56 mol%, 57 mol%, 58 mol%, 59 mol%, 60 mol%, 61 mol%, 62 mol%, 63 mol%, 64 mol%, 65 mol%, 66 mol%, 67 mol%, 68 mol%, 69 mol%, 70 mol%, 71 mol%, 72 mol%, 73 mol%, 74 mol%, or 75 mol% SiO2.

[0053] Li₂O can provide the basis for the lithium disilicate phase. In some embodiments, the glass-ceramic and / or precursor glass may contain 18 mol% to 40 mol% Li₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 18 mol% to 30 mol% Li₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 25 mol% to 36 mol% Li₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 30 mol% to 35 mol% Li₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 18 mol% to 40 mol%, 18 mol% to 36 mol%, 18 mol% to 30 mol%, 18 mol% to 25 mol%, 20 mol% to 40 mol%, 20 mol% to 36 mol%, 20 mol% to 30 mol%, 20 mol% to 25 mol%, 25 mol% to 40 mol%, 25 mol% to 36 mol%, 25 mol% to 30 mol%, 30 mol% to 40 mol%, 30 mol% to 36 mol%, or 36 mol% to 40 mol%. In some embodiments, the glass ceramic and / or precursor glass may contain 18 mol%, 19 mol%, 20 mol%, 21 mol%, 22 mol%, 23 mol%, 24 mol%, 25 mol%, 26 mol%, 27 mol%, 28 mol%, 29 mol%, 30 mol%, 31 mol%, 32 mol%, 33 mol%, 34 mol%, 35 mol%, 36 mol%, 37 mol%, 38 mol%, 39 mol%, or 40 mol% Li₂O.

[0054] Zirconia or zirconium oxide (ZrO2) is the major component of tetragonal and other crystalline ZrO2 phases. In some embodiments, the glass-ceramic and / or precursor glass may contain at least 3 mol% ZrO2, or in some embodiments, 3 mol% to 25 mol% ZrO2. In some embodiments, the glass-ceramic and / or precursor glass may contain 4 mol% to 20 mol% ZrO2. In some embodiments, the glass-ceramic and / or precursor glass may contain 6 mol% to 15 mol% ZrO2. In some embodiments, the glass ceramic and / or precursor glass may contain 3 mol% to 25 mol%, 3 mol% to 20 mol%, 3 mol% to 18 mol%, 3 mol% to 15 mol%, 3 mol% to 12 mol%, 3 mol% to 10 mol%, 3 mol% to 8 mol%, 4 mol% to 25 mol%, 4 mol% to 20 mol%, 4 mol% to 18 mol%, 4 mol% to 15 mol%, 4 mol% to 12 mol%, 4 mol% to 10 mol%, 4 mol% to 8 mol%, 6 mol% to 25 mol%, 6 mol% to 20 mol%, 6 mol% to 18 mol%, 6 mol% to 15 mol%, 6 mol% to 12 mol%, and 6 mol% to 10 mol% ZrO2. In some embodiments, the glass ceramic and / or precursor glass may contain 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 11 mol%, 12 mol%, 13 mol%, 14 mol%, 15 mol%, 16 mol%, 17 mol%, 18 mol%, 19 mol%, 20 mol%, 21 mol%, 22 mol%, 23 mol%, 24 mol%, or 25 mol% ZrO2.

[0055] Al₂O₃ can affect the structure of precursor glasses and / or glass-ceramics, and additionally, lower the liquidus temperature and coefficient of thermal expansion, or enhance the strain point. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol% Al₂O₃. In some embodiments, the glass-ceramic and / or precursor glass may contain >0 mol% to 5 mol% Al₂O₃. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 to 3 mol% Al₂O₃ or >0 mol% to 3 mol% Al₂O₃. In some embodiments, the glass-ceramic and / or precursor glass may contain 1 mol% to 4 mol% Al₂O₃. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, or 1 mol% to 3 mol% Al2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% Al2O3.

[0056] Without being bound by theory, it is believed that limiting the B2O3 content in the glasses and glass-ceramics described herein to 0 wt% to 5 wt% helps to provide durable glass-ceramics. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol% B2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain >0 mol% to 5 mol% B2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol% to 3 mol% B2O3 or >0 mol% to 3 mol% B2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain 1 mol% to 4 mol% B2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, or 1 mol% to 3 mol% B2O3. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% B2O3.

[0057] Phosphorus pentoxide (P₂O₅) may be present to stabilize tetragonal ZrO₂. In some embodiments, the glass-ceramic and / or precursor glass may contain >0 mol% to 5 mol% P₂O₅. In some embodiments, the glass-ceramic and / or precursor glass may contain 0.2 mol% to 5 mol% P₂O₅. In some embodiments, the glass-ceramic and / or precursor glass may contain about >0 mol% to 3 mol% P₂O₅ or 0.2 mol% to 3 mol% P₂O₅. In some embodiments, the glass-ceramic and / or precursor glass may contain 1 mol% to 4 mol% P₂O₅. In some embodiments, the glass-ceramic and / or precursor glass may contain 0.2 mol% to 5 mol%, 0.2 mol% to 4 mol%, 0.2 mol% to 3 mol%, 0.2 mol% to 2 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, or 1 mol% to 3 mol% P2O5. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% P2O5.

[0058] Rare earth oxides may be present to stabilize tetragonal ZrO2. In some embodiments, the glass-ceramic and / or precursor glass comprises 0 mol% to 5 mol% of at least one rare earth oxide (REO; i.e., oxides of scandium, yttrium, and lanthanides) (0 mol% ≤ REO ≤ 5 mol%). In some embodiments, the glass-ceramic and / or precursor glass comprises greater than 0 mol% to 5 mol% of at least one rare earth oxide (REO; i.e., oxides of scandium, yttrium, and lanthanides) (0 mol% < REO ≤ 5 mol%), where 'greater than 0' means any positive value, such as 0.001 mol%. In some embodiments, the glass-ceramic and / or precursor glass may comprise 0 mol% to 3 mol% or greater than 0 mol% to 2 mol% Y2O3 (0 mol% ≤ Y2O3 ≤ 3 mol% or 0 mol% < Y2O3 ≤ 2 mol%). In some embodiments, the ratio of Y₂O₃ (mol%) to ZrO₂ (mol%) is less than 0.2, 0.15, 0.1, 0.05, or 0.1. In some embodiments, the glass-ceramic and / or precursor glass contains 0 mol% to 5 mol%, >0 mol% to 5 mol%, 1 mol% to 5 mol%, 2 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, 0 mol% to 1 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, or >0 mol% to 1 mol%, 0 mol% to about 0.5 mol%, 0 mol% to about 0.1 mol%, 0 mol% to about 0.05 mol%, or 0 mol% to about 0.01 mol% CeO₂.

[0059] Non-lithium alkali metal oxides may also be present in glass ceramics and / or precursor glasses. In some embodiments, the glass ceramics and / or precursor glasses contain 0 mol% to about 14 mol% R₂O (0 mol% < R₂O ≤ 14 mol%), where R is the sum of alkali metals Na, K, Cs, and RB (non-Li) in the glass ceramics and / or precursor glasses. In some embodiments, the glass ceramics and / or precursor glasses may contain 0 mol% to 10 mol% or 0 mol% to 8 mol% R₂O. In some embodiments, the glass ceramics and / or precursor glasses may contain >0 mol% to 14 mol%, >0 mol% to 10 mol%, or >0 mol% to 8 mol% R₂O. In some embodiments, the glass ceramics and / or precursor glasses may contain 0.5 mol% to 4 mol% R₂O. In some embodiments, the glass-ceramic and / or precursor glass may comprise 0 mol% to 14 mol%, 0 mol% to 10 mol%, 0 mol% to 8 mol%, 0 mol% to 6 mol%, 0 mol% to 4 mol%, >0 mol% to 14 mol%, >0 mol% to 10 mol%, >0 mol% to 8 mol%, >0 mol% to 6 mol%, >0 mol% to 4 mol%, 1 mol% to 14 mol%, 1 mol% to 10 mol%, 1 mol% to 8 mol%, 1 mol% to 6 mol%, 2 mol% to 14 mol%, 2 mol% to 10 mol%, 2 mol% to 8 mol%, 2 mol% to 6 mol%, 4 mol% to 14 mol%, 4 mol% to 10 mol%, 4 mol% to 8 mol%, 6 mol% to 14 mol%, 6 mol% to 10 mol%, 8 mol% to 14 mol%, or 8 From mol% to 10 mol% R2O. In some embodiments, the glass ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 11 mol%, 12 mol%, 13 mol%, or 14 mol% R2O.

[0060] Na₂O can be used in glass-ceramic and / or precursor glasses for ion exchange and chemical tempering. In some embodiments, the glass-ceramic and / or precursor glass contains 0 mol% to about 5 mol% Na₂O (0 mol% ≤ Na₂O ≤ 5 mol%). In some embodiments, the glass-ceramic and / or precursor glass may contain greater than 0 mol% to 5 mol% Na₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol% to 3 mol% Na₂O or >0 mol% to 3 mol% Na₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 0.5 mol% to 4 mol% Na₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, or 1 mol% to 3 mol% Na₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% Na₂O.

[0061] K₂O can also be used for ion exchange and may be present in glass ceramics and / or precursor glasses in amounts from 0 mol% to about 10 mol% (0 mol% ≤ K₂O ≤ 10 mol%). In some embodiments, glass ceramics and / or precursor glasses may contain >0 mol% to 10 mol% K₂O. In some embodiments, glass ceramics and / or precursor glasses may contain about 0 mol% to 5 mol% K₂O or >0 mol% to 3 mol% K₂O. In some embodiments, glass ceramics and / or precursor glasses may contain 0.5 mol% to 4 mol% K₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 10 mol%, 0 mol% to 8 mol%, 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, >0 mol% to 10 mol%, >0 mol% to 8 mol%, >0 mol% to 5 mol%, >0 mol% to 3 mol%, 1 mol% to 10 mol%, 1 mol% to 8 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, 1 mol% to 3 mol%, 2 mol% to 10 mol%, 2 mol% to 8 mol%, or 2 mol% to 4 mol% K₂O. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, or 10 mol% K₂O.

[0062] In some embodiments, the precursor glass and glass-ceramic may be free of Cs and Rb. In these embodiments, the term R'2O is used to distinguish it from R2O as described above, where R' is the sum of alkali metals Na and K, but excludes Cs, Li, and Rb. In some embodiments, the glass-ceramic and / or precursor glass contains 0 mol% to about 14 mol% R'2O (0 mol% < R'2O ≤ 14 mol%). In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 10 mol% or 0 mol% to 8 mol% R'2O. In some embodiments, the glass-ceramic and / or precursor glass may contain >0 mol% to 14 mol%, >0 mol% to 10 mol%, or >0 mol% to 8 mol% R'2O. In some embodiments, the glass-ceramic and / or precursor glass may contain 1 mol% to 4 mol% R'2O. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 14 mol%, 0 mol% to 10 mol%, 0 mol% to 8 mol%, 0 mol% to 6 mol%, 0 mol% to 4 mol%, >0 mol% to 14 mol%, >0 mol% to 10 mol%, >0 mol% to 8 mol%, >0 mol% to 6 mol%, >0 mol% to 4 mol%, 1 mol% to 14 mol%, 1 mol% to 10 mol%, 1 mol% to 8 mol%, 1 mol% to 6 mol%, 2 mol% to 14 mol%, 2 mol% to 10 mol%, 2 mol% to 8 mol%, 2 mol% to 6 mol%, 4 mol% to 14 mol%, 4 mol% to 10 mol%, 4 mol% to 8 mol%, 6 mol% to 14 mol%, 6 mol% to 10 mol%, 8 mol% to 14 mol%, or 8 From mol% to 10 mol% R'2O. In some embodiments, the glass ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, 10 mol%, 11 mol%, 12 mol%, 13 mol%, or 14 mol% R'2O.

[0063] Alkaline earth metal oxides can provide advantages for ion exchange in glass-ceramics or precursor glasses, along with improvements to other properties of the material. In some embodiments, the glass-ceramic and / or precursor glass contains 0 mol% to about 10 mol% MO (0 mol% ≤ MO ≤ 10 mol%), where M is the sum of the alkaline earth metals Mg, Ca, Sr, and Ba in the glass-ceramic and / or precursor glass. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 8 mol% MO. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol% MO. In some embodiments, the glass-ceramic and / or precursor glass may contain 1 mol% to 8 mol% MO. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 10 mol%, 0 mol% to 8 mol%, 0 mol% to 6 mol%, 0 mol% to 4 mol%, 1 mol% to 10 mol%, 1 mol% to 8 mol%, 1 mol% to 6 mol%, 2 mol% to 10 mol%, 2 mol% to 8 mol%, or 2 mol% to 6 mol% MO. In some embodiments, the glass-ceramic and / or precursor glass may contain about >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, 5 mol%, 6 mol%, 7 mol%, 8 mol%, 9 mol%, or 10 mol% MO.

[0064] Titanium dioxide (TiO2) can be used alone or in combination with tetragonal ZrO2 to provide improved fracture toughness to glass-ceramics and / or precursor glasses. In some embodiments, the glass-ceramic and / or precursor glass may further comprise 0 mol% to about 10 mol% TiO2, >0 mol% to about 10 mol% TiO2, 0 mol% to about 5 mol% TiO2, or >0 mol% to about 5 mol% TiO2. In some embodiments, the glass ceramic and / or precursor glass may contain 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, 0 mol% to 1 mol%, >0 mol% to 10 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, >0 mol% to 1 mol%, 0.01 mol% to 3 mol%, or 0.1 mol% to 2 mol% TiO2.

[0065] ZnO may be present in glass-ceramics and / or precursor glasses. In some embodiments, the glass-ceramics and / or precursor glasses contain 0 mol% to about 5 mol% ZnO (0 mol% ≤ ZnO ≤ 5 mol%). In some embodiments, the glass-ceramics and / or precursor glasses may contain greater than 0 mol% to 5 mol% ZnO. In some embodiments, the glass-ceramics and / or precursor glasses may contain about 0 mol% to 3 mol% ZnO or >0 mol% to 3 mol% ZnO. In some embodiments, the glass-ceramics and / or precursor glasses may contain 0.5 mol% to 4 mol% ZnO. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to 5 mol%, 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, >0 mol% to 5 mol%, >0 mol% to 4 mol%, >0 mol% to 3 mol%, >0 mol% to 2 mol%, 1 mol% to 5 mol%, 1 mol% to 4 mol%, or 1 mol% to 3 mol% ZnO. In some embodiments, the glass-ceramic and / or precursor glass may contain about 0 mol%, >0 mol%, 1 mol%, 2 mol%, 3 mol%, 4 mol%, or 5 mol% ZnO.

[0066] In some embodiments, the aforementioned glass-ceramic further comprises a color component. The color component may comprise, for example, Fe2O3, V2O5, Cr2O3, TiO2, MnO2, NiO, ZnO, CuO, NiO, Co3O4, rare earth oxides, and combinations thereof. In some cases, the total mol% of the color component is 0 mol% to 4 mol%, 0 mol% to 3 mol%, 0 mol% to 2 mol%, 0 mol% to 1 mol%, >0 mol% to 1 mol%, >0 mol% to 2 mol%, >0 mol% to 3 mol%, or >0 mol% to 4 mol%.

[0067] Additional components may be incorporated into the glass-ceramic and / or precursor glass to provide additional benefits, or may be incorporated as contaminants typically found in commercially prepared glasses. For example, additional components may be added as clarifying agents (e.g., to promote the removal of gaseous inclusions from the molten batch used to produce the glass) and / or for other purposes. In some embodiments, the glass-ceramic and / or precursor glass may contain one or more compounds that can be used as ultraviolet radiation absorbers. In some embodiments, the glass-ceramic and / or precursor glass may contain 3 mol% or less of MnO, Nb₂O₅, MoO₃, Ta₂O₅, WO₃, SnO₂, Fe₂O₃, As₂O₃, Sb₂O₃, Cl, Br, or combinations thereof. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to about 3 mol%, 0 mol% to about 2 mol%, 0 mol% to about 1 mol%, 0 mol% to 0.5 mol%, 0 mol% to 0.1 mol%, 0 mol% to 0.05 mol%, or 0 mol% to 0.01 mol% of MnO, ZnO, Nb2O5, MoO3, Ta2O5, WO3, SnO2, Fe2O3, As2O3, Sb2O3, Cl, Br, or combinations thereof. In some embodiments, the glass-ceramic and / or precursor glass may contain 0 mol% to about 3 mol%, 0 mol% to about 2 mol%, 0 mol% to about 1 mol%, 0 mol% to about 0.5 mol%, 0 mol% to about 0.1 mol%, 0 mol% to about 0.05 mol%, or 0 mol% to about 0.01 mol% of SnO2 or Fe2O3, or combinations thereof. According to some embodiments, the glass may also include various contaminants associated with the batch and / or introduced into the glass via melting, refining, and / or forming equipment used to produce the glass.

[0068] Non-limiting examples of precursor glasses used to form the glass ceramics implemented are listed in Table 1, wherein the values ​​of the components are listed in mol%.

[0069] Table 1

[0070]

[0071] Table 1 (continued)

[0072]

[0073] Table 1 (continued)

[0074]

[0075] As noted above, the glass-ceramics described herein comprise a tetragonal ZrO2 crystalline phase and a lithium disilicate phase. In some embodiments, the glass-ceramics described herein may also contain other subcrystalline phases. These phases can be beneficial for toughening or chemical strengthening by ion exchange processes known in this art (as is the case with β-spodumene solid solutions or glasses). In some cases, the crystalline phases are interlocked or crystals are very close together, leaving an immiscible glass phase. These unique microstructures and phase combinations cannot be obtained using conventional ceramic processing routes—the disclosed methods obtain these microstructures through homogeneous nucleation of the precursor glass, which produces the disclosed phase combinations and microstructures without the need for high-temperature sintering or the risk of heterogeneous dispersion of the ZrO2 phase in the molten glass. Additionally, certain phases can also be used to reduce the coefficient of thermal expansion (CTE) of the glass-ceramic material. Therefore, the glass ceramic may further comprise at least one of the following: lithium aluminosilicate phase, white silica phase, β-spodumene phase, crystalline lithium phosphate (Li3PO4) phase, crystalline lithium orthophosphate phase, quartz solid solution phase, zircon phase, lithium metasilicate (Li2SiO3) phase, monoclinic zirconium oxide phase, sodium lithium silicate phase, cubic zirconium oxide phase, crystalline (Na,Li)ZrSi6O 18 Phase. As used herein, the term "quartz solid solution" includes a solid solution of SiO2 and up to about 50 wt% Li (AlO2).

[0076] Non-limiting examples of the scope of applications for glass ceramics are listed in Table 2, where the values ​​of the components are listed in mol%.

[0077]

[0078]

[0079]

[0080]

[0081]

[0082]

[0083] In addition to high fracture toughness, the glass ceramics described herein may possess color and transparency / transparency properties that make them advantageous for many applications. One or more embodiments of the glass ceramics may exhibit substantially white, “off-white,” milky white, or white-transparent colors. In some embodiments, the glass ceramics exhibit colors in the range of CIELAB color space coordinates (determined by reflectance spectroscopy using a spectrophotometer with an irradiation body of D65 and excluding specular reflection): a* = about -1 to about +3; b* = about -7 to about +3; and L* > 85. In some applications, the glass ceramics are translucent and quantitatively white to yellowish-brown in color, and are of particular interest in dental applications. In such applications, obtaining a glass ceramic with the following CIELAB color space coordinates may be desirable: a* = about -1 to about 1; b* = about -4 to about 1; and L* < 60. In some embodiments, the glass ceramic is qualitatively described as white and opaque, and has a color in the following CIELAB color space coordinates: a* = about -1 to about 0; b* = about -2 to about 0; and L* > 88. In some embodiments, the glass ceramic is qualitatively described as black and opaque, and has a color in the following CIELAB color space coordinates: a* = about -1 to about 1; b* = about -1 to about 1; and L* < 40.

[0084] Table 3 lists the precursor glass and glass-ceramic compositions, heat treatment (ceramization) schedules, and non-limiting examples of phase combinations resulting from different ceramization / heat treatment schedules. Table 3 also includes notes on the general appearance of the formed glass-ceramics.

[0085] Table 3. Precursor composition (in mol%), ceramization time, and examples of phase combinations resulting from different heat treatment times. Note: In Table 3, tetragonal ZrO2 is indicated by “t-ZrO2”, monoclinic ZrO2 by “m-ZrO2”, and quartz solid solution by “quartz ss”.

[0086]

[0087]

[0088]

[0089]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101] In some embodiments, glass precursors and / or glass ceramics may be strengthened to include compressive stress (CS) extending from their surface to the depth of compression (DOC). The compressive stress region is balanced by a central portion exhibiting tensile stress. At the DOC, the stress transitions from positive (compressive) stress to negative (tensile) stress. In one or more embodiments, the glass article may be chemically strengthened by ion exchange or other methods known in the art. In some embodiments, the residual glass phase or glass precursor or glass ceramic contains at least one lithium, sodium, or potassium that enables ion exchange. Ion exchange is commonly used for chemically strengthened glass. In a particular instance, basic cations from a source of these cations (e.g., a molten salt or "ion exchange" bath) exchange with smaller basic cations within the glass to achieve a layer at compressive stress (CS) extending from the glass surface to the depth of compression (DOC) within the glass phase. For example, potassium ions from a cation source are often exchanged with sodium and / or lithium ions within the glass phase, and K + Concentration distribution is related to compressive stress and layer depth.

[0102] Glass-ceramics or precursor glasses can be ion-exchanged by immersion in at least one ion exchange bath containing a molten salt of at least one alkali metal such as lithium, sodium, or potassium (e.g., nitrate, sulfide, halide, or the like). The ion exchange bath may contain one or more salts of a single alkali metal (e.g., sulfides, nitrates, or halides of Li, Na, or K) or salts of two or more alkali metals (e.g., sulfides, nitrates, or halides of Li and Na, or sulfides, nitrates, or halides of Na and K). Ion exchange is carried out in the ion exchange bath at a temperature ranging from about 390°C to about 550°C for a time ranging from about 0.5 hours to about 24 hours.

[0103] In some embodiments, the precursor glass or glass-ceramic is ion-exchanged and has a compression layer extending from the surface to a depth of compression (DOC), which is at least about 10 μm in the glass-ceramic or, in some embodiments, at least about 30 μm, or, in some embodiments, up to about 10%, 15%, 20%, or 25% in the glass, as measured by thickness (surface to center). In some embodiments, the compression layer extends from the surface of the precursor glass or glass-ceramic to a depth of up to about 20% of the thickness of the glass-ceramic. In some embodiments, the precursor glass or glass-ceramic may be strengthened to exhibit surface compressive stresses in the range of 250 MPa to 800 MPa or greater.

[0104] In reinforced glass ceramics, the depth of the compressibility layer can be determined by electron microprobe, glow-discharge optical emission spectroscopy (GDOES, a technique for measuring the depth distribution of constituent elements in a solid sample by detecting the emission of atoms from a plasma by sputtering), or similar techniques that provide compositional data varying with depth. In such similar techniques, the data would be displayed at the surface Na (where Na... + Replace Li in the glass phase +The combination of ) and / or K. The DOC of the precursor glass can be measured using a commercially available instrument such as the FSM-6000 manufactured by Orihara Industrial Co., Ltd. (Japan) using a surface stress meter (FSM). Surface stress measurement relies on the accurate measurement of the stress optical coefficient (SOC), which is related to the birefringence of the glass. SOC is measured by methods known in this art, such as the fiber and four-point bending methods, both described in ASTM standard C770-98 (2013) entitled “Standard Test Method for Measurement of Glass Stress-Optical Coefficient,” the contents of which are incorporated herein by reference in their entirety; and the bulk cylinder method. CS can also be measured using the FSM. As used herein, CS can be “maximum compressive stress,” which is the highest compressive stress value measured within the compressive stress layer. In some embodiments, the maximum compressive stress is located at the surface of the precursor glass or glass-ceramic. In other embodiments, the maximum compressive stress may occur at a depth below the surface, thus giving the compression distribution the appearance of a “buried peak”.

[0105] The reinforced articles disclosed herein can be incorporated into other articles, such as articles having a display (or display articles) (e.g., consumer electronic devices, including mobile phones, tablets, computers, navigation systems, and the like), building articles, transportation articles (e.g., automobiles, trains, airplanes, seaplanes, etc.), electrical articles, or any article benefiting from some transparency, scratch resistance, abrasion resistance, or a combination thereof. In other embodiments, the glass-ceramic forms part of a consumer electronic product, such as a mobile phone or smartphone, a laptop, a tablet, or the like. These consumer electronic products typically include a housing having a front surface, a back surface, and side surfaces, and include electrical components such as power supplies, controllers, memory, displays, and the like, which are at least partially located within the housing. In some embodiments, the glass-ceramic described herein includes at least a portion of a protective element, such as, but not limited to, the housing and / or display of a consumer electronic product.

[0106] An exemplary article incorporated herein by reference to any of the reinforced articles disclosed is, for example, a consumer electronic device comprising: a housing having a front surface, a back surface, and side surfaces; electrical components at least partially or wholly within the housing and included at or near the front surface of the housing, including at least one controller, memory, and display; and a cover plate located at or above the front surface of the housing such that the cover plate is above the display. In some embodiments, at least one of the cover plate or a portion of the housing may comprise any of the reinforced articles disclosed herein.

[0107] The ZrO2-toughened glass-ceramic materials described herein may have the following fracture toughness values ​​as measured by the herringbone notch short bar method (a technique known in this paper and described in ASTM procedure E1304-97): at least 1 MPa·m 1 / 2 1.5 MPa·m 1 / 2 2 MPa·m 1 / 2 3 MPa·m 1 / 2 Or at least 4 MPa·m in some embodiments 1 / 2 In some embodiments, the fracture toughness is in the range of 1 MPa·m. 1 / 2 1.5 MPa·m 1 / 2 2 MPa·m 1 / 2 3 MPa·m 1 / 2 or 4MPa·m 1 / 2 Up to 6 MPa·m 1 / 2 8 MPa·m 1 / 2 or 10 MPa·m 1 / 2 In other embodiments, approximately 1.5 MPa·m 1 / 2 2 MPa·m 1 / 2 3 MPa·m 1 / 2 Up to 8 MPa·m 1 / 2 The results of fracture toughness and flexural strength measurements for the selected samples are provided in Table 3. Example 5-12 in Table 3 illustrates that fracture toughness increases with increasing ZrO2 content.

[0108] In some embodiments, the ZrO2-toughened glass-ceramics described herein are used in dental complexes, filling materials, and articles such as, but not limited to, fillers, bridges, splints, crowns, crown portions, dentures, teeth, clips, inlays, crown bodies, fabrics, panels, facets, implants, cylinders, bridge abutments, or connectors. In addition to glass-ceramics, these dental complexes, filling materials, and articles may also include other additives, such as, but not limited to, stabilizers, flavoring agents, coloring agents (e.g., oxides and sulfides of Mn, V, Ti, Fe, Er, Co, Pr, Tb, Cr, Nd, Ce, V, Eu, Ho, Ni, and Cu, and combinations thereof), antimicrobial active ingredients, fluoride-releasing additives, optical brighteners, plasticizers, UV absorbers, and / or solvents such as water, ethanol, or mixtures thereof. Glass-ceramics can be processed into dental articles using a variety of methods, including but not limited to injection molding, gel casting, slide casting, electroforming, hand forming, CAD / CAM methods, 3D printing, and various other rapid prototyping methods known in this art. In some embodiments, glass-ceramics can be ground into powder, which can then be formed into suspensions, microspheres, raw materials, or pre-sintered blanks before being formed into dental articles.

[0109] Processes used in the manufacture of glass ceramics and glass ceramic precursors

[0110] Precursor glasses having the oxide contents listed in Table 1 can be produced by conventional methods. For example, in some embodiments, precursor glasses can be formed by thoroughly mixing the necessary batch (e.g., using a tubular mixer) to stabilize a homogeneous melt, and then placing it in a silica and / or platinum crucible. The crucible can be placed in a furnace and the glass batch melted at a temperature in the range of 1250–1650°C and held for a period of about 6–16 hours. The melt can then be poured into a steel mold to produce glass sheets. These sheets can then be immediately transferred to an annealing furnace operating at about 500–650°C, where the glass is held at the temperature for about 1 hour and then cooled overnight. In another non-limiting example, precursor glasses are prepared by dry blending appropriate oxides, carbonates, and mineral-derived components for a time sufficient to thoroughly mix the components. The glass is melted in a platinum crucible at a temperature in the range of 1100°C to about 1650°C and held at the temperature for about 16 hours. The resulting molten glass was then poured onto a steel stage for cooling. The precursor glass was subsequently annealed at an appropriate temperature.

[0111] Once the glass composition has been formed, the resulting precursor glass can be ceramicized by heat treatment. Heat treatment is carried out under conditions that induce crystallization of the glass composition to form a ceramic. Typically, this is done via a two-stage heating process, in which the glass is first heated to a lower temperature to induce nucleation, and then heated to a higher temperature to induce crystallization. Non-restrictive conditions include initial heating to 600°C to 850°C, 635°C to 800°C, or 650°C to 750°C for 0.1 to 10 hours, 0.25 to 8 hours, 0.25 to 5 hours, 0.25 to 3 hours, 0.25 to 2 hours, 0.5 to 8 hours, 0.5 to 5 hours, 0.5 to 3 hours, 0.5 to 2 hours, 1 to 9 hours, 1 to 8 hours, 1 to 5 hours, 1 to 3 hours, or 1 to 2 hours (referred to as the nucleation step), followed by heating to 725°C to 1000°C, 725°C to 950°C, or 72... Heating at 5°C to 900°C, or 750°C to 850°C, for 0.1 to 8 hours, 0.1 to 10 hours, 0.25 to 8 hours, 0.25 to 5 hours, 0.25 to 3 hours, 0.25 to 2 hours, 0.5 to 8 hours, 0.5 to 5 hours, 0.5 to 3 hours, 0.5 to 2 hours, 1 to 9 hours, 1 to 8 hours, 1 to 5 hours, 1 to 3 hours, 1 to 2 hours, 2 to 9 hours, 2 to 8 hours, 2 to 5 hours, 2 to 3 hours, or 2 to 4 hours (crystal growth step).

[0112] In an exemplary embodiment, a precursor glass is provided comprising at least about 18 wt% Li2O, at most about 5 wt% Al2O3, and at least about 4 wt% ZrO2. The precursor glass is then heat-treated or “ceramized” to form a glass-ceramic. The ceramization step comprises first heating the precursor material at a first temperature in the range of about 600°C to about 750°C for a first period of about 15 minutes to about 2.5 hours, or in some embodiments, about 15 minutes to about 1 hour, or in other embodiments, about 1.5 hours to about 2.5 hours. After the first heating step, the material is heated at a second temperature in the range of about 725°C to about 1000°C for a second period of about 0.5 hours to about 5 hours, or in some embodiments, about 0.5 hours to about 5 hours, or in other embodiments, about 3 hours to about 5 hours to form the glass-ceramic.

[0113] Alternatively, in some embodiments, the precursor material may comprise a precursor glass and ceramic powder, wherein the ceramic powder comprises ZrO2. In this embodiment, the precursor glass may be ground into a powder having an average particle size of less than about 10 μm and then mixed with the ceramic powder. In some embodiments, the glass-ceramic may then be sintered at a temperature ranging from about 650°C to about 800°C for a time ranging from about 0.5 hours to a maximum of about 4 hours. In other embodiments, the glass-ceramic may be hot-pressed to form a near-net shape.

[0114] While in some embodiments, ZrO2-toughened glass-ceramics have been produced by adding ZrO2 particles to a powdered glass-ceramic precursor glass and then sintering it, these methods involve mixing two different powders, which can introduce inhomogeneities into the final ZrO2 glass-ceramic product. Furthermore, the sintering time and temperature used can induce more grain growth than desired, or have other detrimental effects on the microstructure. In sintering methods, the nucleation and growth of the desired phase can be a mixture of surface and bulk nucleation, resulting in a difficult-to-control or reproducible microstructure. All these challenges can lead to compromised strength and / or fracture toughness values ​​in the final material. Moreover, sintering is often carried out under high pressure in an attempt to achieve full density in the final product. Achieving full density may or may not be achieved, and porosity can become a problem in achieving materials with high strength and fracture toughness.

[0115] As described herein, the production of ZrO2-containing glass-ceramics from homogeneous glass precursors addresses many of the aforementioned problems. Glass can be homogeneously nucleated, and the nucleation and growth steps can be further controlled to produce a final product with optimized microstructure and phase composition. Full density is achieved via the ceramization of the dense precursor glass without the use of high pressure. The precursor glass is produced using conventional glass melting and forming techniques. While some glass compositions containing high amounts of ZrO2 must be melted at high temperatures, many of the Li2O and MgO-containing compositions described herein readily melt at low temperatures (e.g., < 1650 °C). Furthermore, other phases previously described, such as lithium metasilicate, lithium disilicate, β-quartz solid solutions, and β-spodumene solid solutions, can also precipitate in the glass-ceramics. In some embodiments, these microstructures and phase compositions are not readily obtainable using ceramic processing routes.

[0116] Another advantage of the material described herein is its ability to be partially ceramized into a lithium metasilicate phase, subsequently machined and / or finished, and then ceramized again into a fully high fracture toughness final glass-ceramic. During ceramization, lithium metasilicate precipitates first (leaving a ZrO2-enriched glassy phase), allowing for shaping or machining, followed by further ceramization to obtain the t-ZrO2 / LDS phase. In some embodiments, the ZrO2-toughened glass-ceramic described herein is intended for applications such as, but not limited to, valves, blades, cutting tools, knives, components for semiconductor manufacturing (cap rings, etching nozzles, RF shielding, etc.), oil and gas drilling components (downhole pump pistons, control valves, etc.), and ferrules for fiber optic connectors, where high resistance to mechanical wear is desired.

[0117] The glass-ceramics and precursor glasses described herein are readily cast or rolled into homogeneous glass, yielding final geometries such as sheets or spheres. The resulting glass-ceramics can be provided as sheets, which can then be reconstituted into curved or bent parts of uniform thickness by pressing, blowing, bending, sag, vacuum forming, or other means. Reconstitution can be performed prior to heat treatment, or the forming step can also serve as a heat treatment step, wherein forming and heat treatment are substantially simultaneous.

[0118] Example

[0119] Figure 1A and 1B These are scanning electron microscopy (SEM) images showing the implemented glass-ceramic with ZrO2 and other phases present in the sample. Figure 1A The image shows a glass-ceramic material (composition example 6 in Table 3), which is ceramized by first heating at 750°C for 2 hours and then heating at 900°C for 4 hours. Figure 1B Images are of a glass-ceramic material (composition example 10 in Table 3), which was ceramized by first heating at 800°C for 2 hours and then at 900°C for 4 hours. The microstructure of the material in both images is homogeneous. Figure 1A and 1B The dark gray rod-shaped substance 120 is lithium disilicate, while Figure 1A and 1B The white phase 110 in the sample is ZrO2. The ZrO2 grains 110 are approximately 1 μm in size. X-ray diffraction studies of these samples revealed that the zirconia phase is mainly tetragonal ZrO2. The sample ceramized at 900 °C (Figure 1B) appears larger by SEM than the sample ceramized at 800 °C for 4 hours. Figure 1A It contains a relatively high amount of tetragonal ZrO2 phase.

[0120] Figures 2A-2D This is a SEM image of the indentation area on the surface of a glass-ceramic (composition example 6 in Table 3), which was ceramized by first heating at 750°C for 2 hours and then at 875°C for 4 hours. The image shows cracks at different magnifications. Figure 2A At 100x magnification; Figure 2B At 500x magnification; Figure 2C At a magnification of 2500x; Figure 2D (At 10,000x magnification). Under an indentation load of 50 kgf, the samples exhibit crack deflection and tortuous crack paths, indicating a toughening mechanism.

[0121] Figures 3A-3D This is the crystal microstructure of Example 8, along with SEM elemental mappings of some components of Example 8, wherein... Figure 3B Showing silicon present in the material, Figure 3C Zirconia is displayed, and Figure 3D Phosphorus is displayed.

[0122] Figures 4A-4D The accompanying figures show the X-ray diffraction spectra of the phase combinations of the implemented glass-ceramic. The figures also show that lithium disilicate (LS2) and tetragonal ZrO2 (t-ZrO2) are present in various embodiments along with many other phases (lithium metasilicate (LMS), monoclinic ZrO2 (m-ZrO2)). Figure 4A This demonstrates the phase combination of Example 8. Figure 4B For the phase combination of Example 14, Figure 4C For example, the phase combination of 40, and Figure 4D This is the phase combination of Example 44. All examples were ceramized at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours, except for Example 44, which was ceramized at 750°C for 2 hours, followed by ceramization at 850°C for 4 hours.

[0123] Figure 5This data pertains to abraded ring-on-ring (ARoR) measurements of 0.8 mm thick samples of ZrO2-toughened glass-ceramics (Example 8) that were ion-exchanged and non-ion-exchanged, wherein the glass-ceramics were ion-exchanged for various times and temperatures. The glass-ceramics were ceramized by first heating at 700°C for 2 hours and then at 850°C for 4 hours. The ring-on-ring test is a known method in this art for measuring the flexural strength of flat glass and glass-ceramic specimens and is described in ASTM C 1499-09 (2013) entitled “Standard Test Method for Monotonic Equibiaxial Flexural Strength of Advanced Ceramics at Ambient Temperature.” ASTM C1499-09 (2013) serves as the basis for the ring-on-ring test methodology described herein. In some cases, glass-ceramic samples were milled using 15 silicon carbide (SiC) particles prior to ring-to-ring testing. These particles were delivered to the glass samples using the methods and apparatus described in Appendix A2, “Abrasion Procedures,” of ASTM C158-02 (2012), entitled “Standard Test Methods for Strength of Glass by Flexure (Determination of Modulus of Rupture).” The contents of ASTM C1499-09 (2013) and ASTM C158-02 (2012), Appendix 2, are incorporated herein by reference in their entirety. The table shows that the glass-ceramics implemented herein can undergo ion exchange, and these ion-exchanged glass-ceramics exhibit improved fracture load values, which are related to the time and temperature in the ion exchange bath.

[0124] Figure 6A and 6B For the exemplary embodiment (Example 14), a comparison of drop performance with ZrO2 ceramic is provided. All components were 0.8 mm thick, dropped onto 180-grit sandpaper and subsequently preserved on 30-grit sandpaper. Example 14 involved ceramization at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours; Comp 1 was a reference transparent glass-ceramic; CoorsTek TTZ was a MgO-stabilized ZrO2 ceramic. The implemented composition exhibited good properties when compared to the transparent glass-ceramic and was consistent with the CoorsTek material. Similarly, Figures 9A-9CMicrographs of scratch tests performed using a Knoop tip on Example 8 under loads of 14 N and 16 N. The exemplary composition was ceramized at 750°C for 2 hours, followed by ceramization at 875°C for 4 hours.

[0125] The colors in Example 8 are measured in CIELAB color space coordinates (using a spectrophotometer, with the irradiation body D65 and excluding specular reflection, by reflectance spectroscopy), namely a*: -0.15, b*: -0.31, and L*: 98.8. Figure 7 Example 8 illustrates the loss tangent of a comparison between a reference glass and a reference glass ceramic. The exemplary composition was ceramicized at 750°C for 2 hours, followed by ceramicization at 875°C for 4 hours. Figure 8 Example 8 illustrates the dielectric constants of a reference glass and a reference glass ceramic. The exemplary composition was ceramicized at 750°C for 2 hours, followed by ceramicization at 875°C for 4 hours.

[0126] While exemplary embodiments have been described for illustrative purposes, the foregoing description should not be construed as limiting the scope of this disclosure or the appended claims. Therefore, various modifications, adaptations, and substitutions will arise to those skilled in the art without departing from the spirit and scope of this disclosure or the appended claims.

Claims

1. A method for preparing glass ceramics from precursor glass, the method comprising: The precursor is ceramized to form the glass-ceramic, thereby partially crystallizing the glass while the other portion remains in an amorphous, non-crystalline residual glass phase; The ceramization process includes homogeneous glass nucleation and crystal growth steps. The glass contains SiO2, Li2O, ZrO2 and P2O5 as components; The glass-ceramic comprises tetragonal zirconium oxide as a first crystalline phase; and the glass-ceramic comprises lithium disilicate as a second crystalline phase.

2. The method of claim 1, wherein the full density of the glass ceramic is achieved by ceramicizing the glass without using high pressure.

3. The method of claim 1, wherein the crystalline phases of the glass ceramic are interlocked or the crystals are very close together, leaving residual miscible glass phases.

4. The method of claim 1, wherein, During the ceramization process, ZrO2 dissolved in the glass mainly crystallizes and precipitates as the tetragonal zirconia phase.

5. The method of claim 1, wherein ceramization comprises heating the precursor material at a first temperature for about 15 minutes to about 3 hours, followed by heating to a second temperature for about 0.5 hours to 5 hours, wherein the first temperature is in the range of 600°C to 850°C and the second temperature is in the range of 725°C to 1000°C.

6. The method of claim 1, wherein, The glass comprises, in mole percentage (mol%): 50-80 mol% SiO2, 18-40 mol% Li₂O 3-25 mol% ZrO2, and Greater than 0-5 mol% P2O5.

7. The method of claim 1, wherein the glass comprises: 50-80 mol% SiO2; 0-5 mol% Al2O3; 0-5 mol% B2O3; 18-40 mol% Li₂O; 0-5 mol% Na2O; 0-10 mol% MO, where MO equals CaO+MgO+SrO+BaO; 0-5 mol% ZnO; 1.5-25 mol% ZrO2; Greater than 0-5 mol% P2O5; and 0-5 mol% REO, where REO is an oxide of scandium, yttrium, and lanthanides.

8. The method of claim 7, wherein the glass-ceramic further comprises monoclinic zirconium oxide and massive lithium phosphate as crystalline phases.

9. A method for processing and / or finishing articles of art, the method comprising: Partial ceramization of glass was performed to prepare glass-ceramics containing the lithium metasilicate phase; Machining and / or finishing of glass and ceramics; and The glass ceramic is then further ceramized to produce a lithium disilicate phase, wherein the glass ceramic also includes a tetragonal zirconia phase.

10. The method of claim 9, wherein the glass comprises SiO2, Li2O, ZrO2 and P2O5 as components.

11. The method of claim 10, wherein, The glass comprises 50-80 mol% SiO2, 18-40 mol% Li2O, 3-25 mol% ZrO2 and more than 0-5 mol% P2O5 by mole percentage (mol%).

12. A method for reproducing glass-ceramic articles, comprising: Reconstruct sheets into curved or bent parts; The remanufactured parts are then subjected to heat treatment. The components include glass ceramics. The glass-ceramic comprises tetragonal zirconium oxide as the first crystalline phase; and The glass-ceramic mentioned herein includes lithium disilicate as the second crystalline phase.

13. The method of claim 12, wherein the reforming and heat treatment are performed simultaneously.

14. The method of claim 12, wherein the reprocessing is performed by pressing, blowing, bending, drooping, or vacuum forming the sheet.

15. A method for strengthening glass-ceramic articles, the method comprising: The glass ceramic is immersed in at least one ion exchange bath containing at least one molten salt of at least one alkali metal, the temperature of the ion exchange bath being in the range of 390°C to 550°C, wherein the glass ceramic is immersed for a time ranging from 0.5 hours to 24 hours. The glass-ceramic comprises tetragonal zirconium oxide and lithium silicate phase and residual glass phase; The glass-ceramic undergoes surface compressive stress after impregnation.

16. The method of claim 15, wherein the glass-ceramic has a compression depth of at least 10 µm and a surface compressive stress in the range of 250 MPa to 800 MPa after impregnation.

17. The method of claim 15, wherein the bath comprises potassium nitrate.

18. The method of claim 15, wherein the lithium silicate comprises lithium disilicate.

19. A method for manufacturing glass, the method comprising: Dry blending of oxides, carbonates, and mineral sources to thoroughly mix the sources, wherein the sources comprise, in molar percentages (mol%) based on oxides: 50-80 mol% SiO2, 18-40 mol% Li₂O 3-25 mol% ZrO2, and Greater than 0-5 mol% P2O5, The source is melted at a temperature ranging from about 1100°C to about 1650°C to produce molten glass; and Pour and cool the molten glass. The glass described herein dissolves ZrO2 and does not crystallize upon cooling from a pouring position.

20. The method of claim 19, wherein during the melting process, the source is maintained at the temperature for 6 to 16 hours.

21. The method of claim 19, wherein the melting is carried out in a platinum crucible.

22. The method of claim 19, wherein after melting, the glass is transferred to an annealing furnace.

23. The method of claim 22, wherein the annealing furnace operates at 500 to 650°C.

24. The method of claim 19, wherein the glass comprises: 50-80 mol% SiO2; 0-5 mol% Al2O3; 0-5 mol% B2O3; 18-40 mol% Li₂O; 0-5 mol% Na2O; 0-10 mol% MO, where MO equals CaO+MgO+SrO+BaO; 0-5 mol% ZnO; 1.5-25 mol% ZrO2; Greater than 0-5 mol% P2O5; and 0-5 mol% REO, where REO is an oxide of scandium, yttrium, and lanthanides.

25. A consumer electronic device, comprising: A housing having a front surface, a back surface, and side surfaces; Electrical components, at least partially located inside the housing, include a controller, memory, and a display; The display is located on or adjacent to the front surface of the housing; The housing described herein comprises glass-ceramic. The glass-ceramic comprises tetragonal zirconia and lithium silicate phase and residual glass phase.

26. The consumer electronic device of claim 25, wherein the glass ceramic is strengthened to include surface compressive stress.

27. The consumer electronic device of claim 25, wherein the glass ceramic is white and opaque.

28. The consumer electronic device of claim 27, wherein the color of the glass ceramic in the CIELAB color space coordinates has a* from -1 to 0; b* from -2 to 0; and L* greater than 88.

29. A glass-ceramic comprising: Residual glass phase; and The homogeneous nucleated crystalline phase comprises a first crystalline phase containing a zirconium oxide phase and a second crystalline phase containing a lithium silicate phase.

30. The glass-ceramic of claim 29, wherein the zirconium oxide phase comprises tetragonal zirconium oxide.

31. The glass-ceramic of claim 30, wherein the tetragonal zirconium oxide comprises 5 to 60 wt% of the crystalline phase.

32. The glass-ceramic of claim 30, wherein the average crystal size of the tetragonal zirconia crystal along its longest dimension is in the range of 100 nm to 10 µm.

33. The glass-ceramic of claim 30, wherein the lithium silicate phase comprises lithium disilicate.

34. The glass-ceramic of claim 33, wherein the lithium disilicate comprises 5 to 50 wt% of the crystalline phase.

35. The glass-ceramic of claim 33, wherein the average crystal size of the lithium disilicate crystal along its longest dimension is in the range of 2µm to 20µm.

36. The glass-ceramic of claim 33, wherein the residual glass phase comprises 1 to 50 wt% of the glass-ceramic.

37. A glass-ceramic comprising, by means of, SiO2, Li2O, ZrO2 and P2O5 as oxide components, wherein the glass-ceramic comprises: Residual glass phase; and The crystalline phase, wherein the crystalline phase comprises tetragonal zirconium oxide.

38. The glass-ceramic of claim 37, wherein the ZrO2 is at least 3 mol of the glass.

39. The glass-ceramic of claim 38, wherein the Li₂O is 18-40 mol of the glass.

40. The glass-ceramic of claim 39, wherein the P2O5 is greater than 0-5 mol of the glass.

41. The glass-ceramic of claim 40, wherein the SiO2 is 50-75 mol% of the glass.

42. The glass-ceramic of claim 37, wherein the crystalline phase further comprises monoclinic zirconium oxide.

43. The method of claim 37, wherein the glass comprises: 50-80 mol% SiO2; 0-5 mol% Al2O3; 0-5 mol% B2O3; 18-40 mol% Li₂O; 0-5 mol% Na2O; 0-10 mol% MO, where MO equals CaO+MgO+SrO+BaO; 0-5 mol% ZnO; 1.5-25 mol% ZrO2; Greater than 0-5 mol% P2O5; and 0-5 mol% REO, where REO is an oxide of scandium, yttrium, and lanthanides.

44. An article comprising a glass-ceramic achieving full density, said glass-ceramic comprising: Residual glass phase; and A crystalline phase containing tetragonal zirconium oxide, The glass-ceramic is strengthened to include compressive stress extending from its surface to the compression depth.

45. The article of claim 44, wherein the compression depth is at least 10 µm.

46. ​​The article of claim 44, wherein the compressive stress includes surface compressive stress in the range of 250 MPa to 800 MPa.

47. A type of glass, comprising: 50-80 mol% SiO2; 0-5 mol% Al2O3; 0-5 mol% B2O3; 18-40 mol% Li₂O; 0-5 mol% Na2O; 0-10 mol% MO, where MO equals CaO+MgO+SrO+BaO; 0-5 mol% ZnO; 1.5-25 mol% ZrO2; Greater than 0-5 mol% P2O5; and 0-5 mol% REO, where REO is an oxide of scandium, yttrium, and lanthanides.

48. The glass of claim 47, wherein the ZrO2 is 4-10 mol%.

49. The glass of claim 48, wherein the P2O5 is 1-5 mol%.

50. The glass of claim 49, wherein the Li₂O is 25-36 mol%.

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