BACKGROUND

Field

The present specification generally relates to stress profiles for fracture resistant stress profiles in glass-based articles. More specifically, the present specification is directed to stress profiles for glass-based articles, which may be lithium-containing, that may be utilized in electronic devices.

Technical Background

The mobile nature of portable devices, such as smart phones, tablets, portable media players, personal computers, and cameras, makes these devices particularly vulnerable to accidental dropping on hard surfaces, such as the ground. These devices typically incorporate cover glasses, which may become damaged upon impact with hard surfaces. In many of these devices, the cover glasses function as display covers, and may incorporate touch functionality, such that use of the devices is negatively impacted when the cover glasses are damaged.

There are two major failure modes of cover glass when the associated portable device is dropped on a hard surface. One of the modes is flexure failure, which is caused by bending of the glass when the device is subjected to dynamic load from impact with the hard surface. The other mode is sharp contact failure, which is caused by introduction of damage to the glass surface. Impact of the glass with rough hard surfaces, such as asphalt, granite, etc., can result in sharp indentations in the glass surface. These indentations become failure sites in the glass surface from which cracks may develop and propagate.

It has been a continuous effort for glass makers and handheld device manufacturers to improve the resistance of handheld devices to failure. It is also desirable that portable devices be as thin as possible. Accordingly, in addition to strength, it is also desired that glasses to be used as cover glass in portable devices be made as thin as possible. Thus, in addition to increasing the strength of the cover glass, it is also desirable for the glass to have mechanical characteristics that allow it to be formed by processes that are capable of making thin glass-based articles, such as thin glass sheets.

Accordingly, a need exists for glasses that can be strengthened, such as by ion exchange, and that have the mechanical properties that allow them to be formed as thin glass-based articles.

SUMMARY

Aspects of the disclosure pertain to glass-based articles and methods for their manufacture and use. Glass-based articles herein exhibit excellent drop performance.

In an embodiment, a glass-based article comprises: a glass-based substrate comprising opposing first and second surfaces defining a substrate thickness (t); and a stress profile comprising: a peak compressive stress (CS) greater than or equal to 700 MPa; a peak tension (PT) less than or equal to 61 MPa; a depth of compression (DOC) that is greater than or equal to 0.1 t; a depth of layer of a spike (DOLsp) that is greater than or equal to 4.5 micrometers; and a stress slope of the spike that is greater than or equal to 40 MPa/micrometer.

In an embodiment, a glass-based article comprises: a glass-based substrate comprising opposing first and second surfaces defining a substrate thickness (t); and a central composition at the center of the glass-based article comprising lithium; a potassium (K) concentration profile that is substantially linear from a maximum K concentration to a concentration of K that is less than or equal to 50% of the maximum K concentration; and a stress profile comprising: a depth of layer of the spike (DOLsp) that is greater than or equal to 0.005 t.

According to some embodiments, a stress profile for a lithium-containing glass-based article is provided that exhibits excellent drop performance and damage resistance.

In an embodiment, a method of manufacturing a glass-based article comprises: exposing a glass-based substrate to a single molten salt bath to form the glass-based article, wherein the glass-based substrate contains lithium, the glass-based substrate has opposing first and second surfaces defining a substrate thickness (t) and the molten bath comprises: potassium nitrate (KNO3); and potassium carbonate (K2CO3) that is dissolved in the potassium nitrate (KNO3); wherein the concentration of the K2CO3remains at or below its solubility limit, and the concentration of lithium ions in the molten salt bath remains at or below its solubility limit.

According to aspect (1), a glass-based article is provided. The glass-based article comprises: a glass-based substrate comprising opposing first and second surfaces defining a substrate thickness (t); and a stress profile comprising: a peak compressive stress (CS) greater than or equal to 700 MPa; a peak tension (PT) less than or equal to 61 MPa; a compressive stress at a knee (CSk); a depth of compression (DOC) that is greater than or equal to 0.1t; a spike region extending from the first surface to a depth of layer of a spike region (DOLsp), where DOLspis greater than or equal to 4.5 micrometers; and a stress slope of the spike region that is greater than or equal to 40 MPa/micrometer.

According to aspect (2), the glass-based article of aspect (1) is provided, further comprising a potassium (K) concentration profile that is substantially linear from a maximum K concentration to a point where the K concentration is less than or equal to 50% of the maximum K concentration.

According to aspect (3), a glass-based article is provided. The glass-based article comprises: a glass-based substrate comprising opposing first and second surfaces defining a substrate thickness (t); a central composition at the center of the glass-based article comprising lithium; a potassium (K) concentration profile that is substantially linear from a maximum K concentration to a point where the K concentration is less than or equal to 50% of the maximum K concentration; and a stress profile comprising: a peak compressive stress (CS), a peak tension (PT), a compressive stress at a knee (CSk); a depth of compression (DOC); and a spike region extending from the first surface to a depth of layer of a spike region (DOLsp), where DOLspis greater than or equal to 0.005t.

According to aspect (4), the glass-based article of aspect (3) is provided, wherein the CS is greater than or equal to 700 MPa.

According to aspect (5), the glass-based article of any of aspects (3) to (4) is provided, wherein the PT is less than or equal to 61 MPa.

According to aspect (6), the glass-based article of any of aspects (3) to (5) is provided, wherein the DOC is greater than or equal to 0.1 t.

According to aspect (7), the glass-based article of any of aspects (3) to (6) is provided, wherein a stress slope of the spike region is greater than or equal to 40 MPa/micrometer.

According to aspect (8), the glass-based article of any of aspects (1) to (7) is provided, wherein t is greater than or equal to 0.35 mm and less than or equal to 1 mm.

According to aspect (9), the glass-based article of any of aspects (1) to (8) is provided, wherein a lithium oxide (Li2O) to sodium oxide (Na2O) molar ratio (Li2O/Na2O) at the center of the glass-based article is in the range of from 0.3 to 1.1.

According to aspect (10), the glass-based article of any of aspects (2) to (9) is provided, wherein the potassium (K) concentration profile is substantially linear from a maximum K concentration to a point where the K concentration is less than or equal to 20% of the maximum K concentration.

According to aspect (11), the glass-based article of aspect (10) is provided, wherein a second derivative of the K concentration profile over a first derivative of the K concentration profile is less than or equal to a value over a region extending from the first surface to a depth where a K concentration is equal to the sum of: a) the K concentration at the center of the glass-based article, and b) 20% of the difference between the peak K concentration and the K concentration at the center of the glass-based article, wherein the value is 0.5, 0.4, or 0.3 of what is typical for an erfc function at the location where the erfc function decreases to 20% of its peak value.

According to aspect (12), the glass-based article of any of aspects (1) to (11) is provided, wherein the potassium (K) concentration profile is substantially linear from the location of CSmaxto a point having a stress of less than or equal to 50% of the CSmax.

According to aspect (13), the glass-based article of any of aspects (1) to (12) is provided, wherein the CSmaxis greater than or equal to 800 MPa.

According to aspect (14), the glass-based article of any of aspects (1) to (13) is provided, wherein the CSmaxis greater than or equal to 820 MPa.

According to aspect (15), the glass-based article of any of aspects (1) to (14) is provided, wherein the CSmaxis greater than or equal to 850 MPa.

According to aspect (16), the glass-based article of any of aspects (1) to (15) is provided, wherein the PT is less than or equal to 60 MPa.

According to aspect (17), the glass-based article of any of aspects (1) to (16) is provided, wherein the PT is less than or equal to 55 MPa.

According to aspect (18), the glass-based article of any of aspects (1) to (17) is provided, wherein the PT is less than or equal to 50 MPa.

According to aspect (19), the glass-based article of any of aspects (1) to (18) is provided, wherein the PT is less than or equal to 45 MPa.

According to aspect (20), the glass-based article of any of aspects (1) to (19) is provided, wherein the PT is less than or equal to 40 MPa.

According to aspect (21), the glass-based article of any of aspects (1) to (20) is provided, wherein the PT is less than or equal to 35 MPa.

According to aspect (22), the glass-based article of any of aspects (1) to (21) is provided, wherein the PT is less than or equal to 30 MPa.

According to aspect (23), the glass-based article of any of aspects (1) to (22) is provided, wherein the CSkis greater than or equal to 40 MPa.

According to aspect (24), the glass-based article of any of aspects (1) to (23) is provided, wherein the CSkis greater than or equal to 50 MPa.

According to aspect (25), the glass-based article of any of aspects (1) to (24) is provided, wherein the CSkis greater than or equal to 60 MPa.

According to aspect (26), the glass-based article of any of aspects (1) to (25) is provided, wherein the CSkis less than or equal to 140 MPa.

According to aspect (27), the glass-based article of any of aspects (1) to (26) is provided, wherein the CSkis less than or equal to 130 MPa.

According to aspect (28), the glass-based article of any of aspects (1) to (27) is provided, wherein the CSkis less than or equal to 120 MPa.

According to aspect (29), the glass-based article of any of aspects (1) to (28) is provided, wherein the DOC is greater than or equal to 0.12 t.

According to aspect (30), the glass-based article of any of aspects (1) to (29) is provided, wherein the DOC is greater than or equal to 0.13 t.

According to aspect (31), the glass-based article of any of aspects (1) to (30) is provided, wherein the DOC is greater than or equal to 0.14 t.

According to aspect (32), the glass-based article of any of aspects (1) to (31) is provided, wherein the DOC is less than or equal to 0.18 t.

According to aspect (33), the glass-based article of any of aspects (1) to (32) is provided, wherein the DOC is less than or equal to 0.17 t.

According to aspect (34), the glass-based article of any of aspects (1) to (33) is provided, wherein the DOC is greater than or equal to 5 micrometers.

According to aspect (35), the glass-based article of any of aspects (1) to (34) is provided, wherein the DOC is less than or equal to 85 micrometers.

According to aspect (36), the glass-based article of any of aspects (1) to (35) is provided, wherein the DOLspis greater than or equal to 4.5 micrometers and less than or equal to 24 micrometers.

According to aspect (37), the glass-based article of any of aspects (1) to (36) is provided, wherein a ratio of DOC/DOLspis greater than or equal to 10 and less than or equal to 23.

According to aspect (38), the glass-based article of any of aspects (1) to (37) is provided, comprising a merit index (MI) defined by CS*DOL*CSk*DOC/PT0.5, wherein the MI is in the range of greater than or equal to 3×106to less than or equal to 30×106MPa2μm2/MPa0.5.

According to aspect (39), the glass-based article of any of aspects (1) to (38) is provided, comprising a damage resistant force (DRF) ratio defined by CS*DOL/CSk*DOC, wherein the DRF is in the range of greater than or equal to 0.1 to less than or equal to 5.

According to aspect (40), the glass-based article of any of aspects (1) to (39) is provided, wherein a Li2O concentration at the center of the glass-based-based article is less than or equal to 12 mol %.

According to aspect (41), the glass-based article of any of aspects (1) to (40) is provided, wherein a Li2O concentration at the center of the glass-based-based article is less than or equal to 11 mol %.

According to aspect (42), the glass-based article of any of aspects (1) to (41) is provided, wherein a Li2O concentration at the center of the glass-based-based article is less than or equal to 10 mol %.

According to aspect (43), the glass-based article of any of aspects (1) to (42) is provided, wherein a Li2O concentration at the center of the glass-based article is less than or equal to 9.5 mol %.

According to aspect (44), the glass-based article of any of aspects (1) to (43) is provided, wherein a Li2O concentration at the center of the glass-based-based article is less than or equal to 9 mol %.

According to aspect (45), the glass-based article of any of aspects (1) to (44) is provided, wherein a Li2O concentration at the center of the glass-based article is less than or equal to 8.5 mol %.

According to aspect (46), the glass-based article of any of aspects (1) to (45) is provided, wherein the Li2O concentration at the center of the glass-based article is less than or equal to 8 mol %.

According to aspect (47), the glass-based article of any of aspects (1) to (46) is provided, wherein the stress profile does not contain a region of negative second derivative of CS(t) at a depth of greater than or equal to DOLspand less than or equal to DOC.

According to aspect (48), a glass-based article is provided. The glass-based article comprises: first and second surfaces defining a thickness (t), wherein the thickness is greater than or equal to 0.1 mm to less than or equal to 2 mm; and a stress profile comprising: a peak compressive stress (CS) greater than or equal to 800 MPa; a peak tension (PT) less than or equal to 61 MPa; a compressive stress at a knee (CSk) greater than or equal to 25 MPa; a depth of compression (DOC) that is greater than or equal to 0.1 t; a spike region extending from the first surface to a depth of layer of a spike region (DOLsp), where DOLspis greater than or equal to 7 μm.

According to aspect (49), the glass-based article of aspect (48) is provided, wherein the CS is greater than or equal to 850 MPa.

According to aspect (50), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the CS is less than or equal to 1000 MPa.

According to aspect (51), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the PT is greater than or equal to 30 MPa.

According to aspect (52), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the CSkis less than or equal to 140 MPa.

According to aspect (53), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOC is less than or equal to 0.18 t.

According to aspect (54), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOC is greater than or equal to 80 μm.

According to aspect (55), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOC is less than or equal to 150 μm.

According to aspect (56), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOLspis less than or equal to 10 μm.

According to aspect (57), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOLspis greater than or equal to 0.0055t.

According to aspect (58), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the DOLspis less than or equal to 0.025 t.

According to aspect (59), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the t is greater than or equal to 0.4 mm to less than or equal to 1.3 mm.

According to aspect (60), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein a value of CSk/t is greater than or equal to 40 MPa/mm.

According to aspect (61), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein the glass-based article comprises lithium.

According to aspect (62), the glass-based article of any of aspects (48) to the preceding aspect is provided, wherein a stress slope of the spike region is greater than or equal to 40 MPa/μm.

According to aspect (63), a consumer electronic product is provided. The consumer electronic product comprises: a housing comprising a front surface, a back surface, and side surfaces; electrical components provided at least partially within the housing, the electrical components comprising at least a controller, a memory, and a display, the display being provided at or adjacent the front surface of the housing; and a cover disposed over the display; wherein a portion of at least one of the housing and the cover comprises the glass-based article of any of aspects (1) to (62).

According to aspect (64), a method of manufacturing a glass-based article is provided. The method comprising: exposing a glass-based substrate to a single molten salt bath to form the glass-based article, wherein the glass-based substrate contains lithium, the glass-based substrate has opposing first and second surfaces defining a substrate thickness (t) and the molten bath comprises: potassium nitrate (KNO3); and potassium carbonate (K2CO3) that is dissolved in the molten bath; wherein the concentration of the K2CO3remains at or below its solubility limit in the molten bath, and the concentration of lithium ions in the molten bath remains at or below its solubility limit in the molten bath.

According to aspect (65), the method of aspect (64) is provided, wherein the molten salt bath further comprises: sodium nitrate (NaNO3); and sodium carbonate (Na2CO3) that is dissolved in the molten bath; wherein the concentration of the Na2CO3remains at or below its solubility limit in the molten bath.

According to aspect (66), the method of any of aspects (64) to (65) is provided, wherein the glass-based article comprises a peak compressive stress (CS) greater than or equal to 700 MPa; a peak tension (PT) less than or equal to 50 MPa; a compressive stress at a knee (CSk); and a depth of compression (DOC) that is greater than or equal to 0.1 t.

According to aspect (67), the method of any of aspects (64) to (66) is provided, further comprising increasing the CS without decreasing the CSkrelative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (68), the method of any of aspects (64) to (67) is provided, further comprising increasing the CS without decreasing the PT relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (69), the method of any of aspects (64) to (68) is provided, further comprising increasing the CSkwithout decreasing the CS relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (70), the method of any of aspects (64) to (69) is provided, further comprising increasing the CSkwithout decreasing the CS relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (71), the method of any of aspects (64) to (70) is provided, further comprising reducing the CS degradation as to an increase of Li poisoning ion concentration relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (72), the method of any of aspects (64) to (71) is provided, further comprising reducing the CSkdegradation as to an increase of Li poisoning ion concentration relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (73), the method of any of aspects (64) to (72) is provided, further comprising reducing the PT degradation as to an increase of Li poisoning ion concentration relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (74), the method of any of aspects (64) to (73) is provided, further comprising maintaining weight gain as to an increase of Li poisoning ion concentration relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (75), the method of any of aspects (64) to (74) is provided, further comprising increasing a merit index (MI) defined by CS*DOL*CSk*DOC/PT0.5relative to exposing the glass-based substrate to a bath comprising the KNO3salt in the absence of the K2CO3salt.

According to aspect (76), a method of manufacturing a glass-based article is provided. The method comprising: exposing a glass-based substrate to a single molten salt bath to form the glass-based article, wherein the glass-based article is the glass-based article of any of aspects (1) to (62).

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

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

