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EP-4735394-A1 - ION EXCHANGEABLE GLASS-BASED ARTICLES HAVING HIGH FRACTURE TOUGHNESS

EP4735394A1EP 4735394 A1EP4735394 A1EP 4735394A1EP-4735394-A1

Abstract

A glass composition can include from 60 mol% to 69 mol% SiO 2 , from 10 mol% to 18 mol% Al 2 O 3 , from 2.3 mol% to 6.9 mol% Li 2 O, from 2.1 mol% to 6.7 mol% Na 2 O, and from 1.1 mol% to 9 mol% alkaline earth metal oxides. The glass composition can comprise a liquidus viscosity greater than or equal to 150 kP. The glass composition can include from 0.25 mol% to 1 mol% K 2 O, from 0.5 mol% to 4 mol% P 2 O 5 , and/or 0.5 mol% to 3.6 mol% B 2 O 3 . The glass composition can form anorthoclase or a feldspar solid solution. The glass composition can include MgO + Li 2 O – (CaO + SrO + Na 2 O + K 2 O) is from -0.5 to -4. The glass composition can include volume electrical resistivity is greater than or equal to 2 x 10 15 Ohm-centimeters. The glass composition may have a fracture toughness of greater than or equal 0.75 MPa√m.

Inventors

  • CLARK, Michael Morris
  • DECKER, Jeffrey Alan
  • GUO, Xiaoju
  • GUO, ZHENHUA
  • HUBERT, Mathieu Gerard Jacques
  • LEZZI, PETER JOSEPH
  • ORAM, PASCALE
  • TOSTANOSKI, Nicholas John
  • ZHU, BIN

Assignees

  • Corning Incorporated

Dates

Publication Date
20260506
Application Date
20240619

Claims (20)

  1. 1. A glass-based article comprising a composition, based on an oxide basis of the glassbased article, comprising: from greater than or equal to 60 mol% to less than or equal to 69 mol% SiCh; from greater than or equal to 10 mol% to less than or equal to 18 mol% AI2O3; from greater than or equal to 2.3 mol% to less than or equal to 6.9 mol% Li2O; from greater than or equal to 2.1 mol% to less than or equal to 6.7 mol% Na2O; and from greater than or equal to 0.25 mol% to less than or equal to 1 mol% K2O; and from greater than or equal to 1.1 mol% to less than or equal to 9 mol% RO, where RO is a sum of amounts of MgO, CaO, SrO, BaO, and ZnO, wherein a liquidus viscosity of the composition is greater than or equal to 150 kiloPoise.
  2. 2. The glass-based article of claim 1, wherein the liquidus viscosity is greater than or equal to 175 kiloPoise.
  3. 3. The glass-based article of any one of claims 1-2, wherein the composition crystalizes to have a primary crystal phase comprising anorthoclase or a feldspar solid solution after being heated at 1050°C for 24 hours.
  4. 4. The glass-based article of any one of claims 1-3, wherein a value of MgO + IJ2O - (CaO + SrO + Na2O + K2O) in mol% is from greater than or equal to -4 to less than or equal to -0.5.
  5. 5. The glass-based article of claim 4, wherein the value of MgO + I 2O - (CaO + SrO + Na2O + K2O) in mol% is from greater than or equal to -1.5 to less than or equal to -1.0.
  6. 6. The glass-based article of any one of claims 1-5, wherein the composition comprises: from greater than or equal to 10 mol% to less than or equal to 16 mol% AI2O3; greater than or equal to 0.5 mol% to P2O5; and from greater than or equal to 0.5 mol% to less than or equal to 3.6 mol% B2O3.
  7. 7. The glass-based article of any one of claims 1-6, wherein the composition comprises: from greater than or equal to 2 mol% to less than or equal to 3.6 mol% B2O3.
  8. 8. The glass-based article of any one of claims 1-7, wherein a volume electrical resistivity is greater than or equal to 2 x 10 15 Ohm-centimeters.
  9. 9. The glass-based article of claim 8, wherein the volume electrical resistivity is from greater than or equal to 1 x 10 16 Ohm-centimeters to less than or equal to 1 x 10 17 Ohmcentimeters.
  10. 10. The glass-based article of any one of claims 1-9, wherein the composition comprises: from greater than or equal to 14 mol% to less than or equal to 16 mol% AI2O3.
  11. 11. The glass-based article of any one of claims 1-10, wherein the composition comprises: from greater than or equal to 60 mol% to less than or equal to 66 mol% SiCh; from greater than or equal to 14 mol% to less than or equal to 16 mol% AI2O3; from greater than or equal to 5 mol% to less than or equal to 6.9 mol% Li2O; from greater than or equal to 4 mol% to less than or equal to 6 mol% Na2O; from greater than or equal to 0.5 mol% to less than or equal to 3 mol% P2O5; and from greater than 0 mol% to less than or equal to 1 mol% TiCh.
  12. 12. The glass-based article of any one of claims 1-11, wherein the composition comprises: from greater than or equal to 6 mol% to less than or equal to 6.7 mol% Li2O; and from greater than or equal to 5 mol% to less than or equal to 5.8 mol% Na2O.
  13. 13. The glass-based article of any one of claims 1-12, wherein: a molar ratio of Li2O/Na2O is from greater than or equal to 1.2 to less than or equal to 2.1.
  14. 14. The glass-based article of any one of claims 1-13, wherein the glass-based article is substantially free of Ta2Os, HfCh, La2Ch, and Y2O3.
  15. 15. The glass-based article of any one of claims 1-14, wherein the composition is substantially free of ZnO and ZrCh.
  16. 16. The glass-based article of any one of claims 1-15, further comprising: from greater than or equal to 0.1 mol% to less than or equal to 0.5 mol% TiCh; and from greater than or equal to 0.1 mol% to less than or equal to 1 mol% K2O.
  17. 17. The glass-based article of any one of claims 1-16, wherein the composition comprises: from greater than or equal to 0.25 mol% to less than or equal to 1 mol% K2O.
  18. 18. The glass-based article of any one of claims 1-17, wherein the composition comprises: from greater than or equal to 1.5 mol% to less than or equal to 3.3 mol% RO.
  19. 19. The glass-based article of any one of claims 1-18, wherein the composition comprises: from greater than or equal to 0.1 mol% to less than or equal to 0.9 mol% MgO.
  20. 20. The glass-based article of any one of claims 1-19, wherein the composition comprises: from greater than or equal to 0.6 mol% to less than or equal to 1.5 mol% SrO.

Description

ION EXCHANGEABLE GLASS- BASED ARTICLES HAVING HIGH FRACTURE TOUGHNESS BACKGROUND [0001] This application claims the benefit of priority under 35 U.S.C. § 119 of U.S. Provisional Application Serial No. 63/523,718 filed on June 28, 2023, and U.S. Provisional Application Serial No. 63/585,351 filed on September 26, 2023, the content of each is relied upon and incorporated herein by reference in their entirety. Field [0002] The present specification generally relates to glass-based compositions suitable for use as a cover glass for electronic devices. More specifically, the present specification is directed to ion exchangeable glass-based articles that may be formed into cover glass for electronic devices. Technical Background [0003] 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. [0004] 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. [0005] Glass can be made more resistant to flexure failure by the ion-exchange technique, which involves inducing compressive stress in the glass surface. However, the ion-exchanged glass will still be vulnerable to dynamic sharp contact, owing to the high stress concentration caused by local indentations in the glass from the sharp contact. [0006] It has been a continuous effort for glass makers and handheld device manufacturers to improve the resistance of handheld devices to sharp contact failure. Solutions range from coatings on the cover glass to bezels that prevent the cover glass from impacting the hard surface directly when the device drops on the hard surface. However, due to the constraints of aesthetic and functional requirements, it is very difficult to completely prevent the cover glass from impacting the hard surface. [0007] 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 a 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. [0008] 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 glassbased articles. SUMMARY [0009] There are set forth herein lithium aluminosilicate glasses with good ion exchangeability, good glass quality, and high fracture toughness. Chemical strengthening processes can be used to achieve high strength and high toughness properties in lithium aluminosilicate glasses. The substitution of AI2O3 into the silicate glass network increases the interdiffusivity of monovalent cations during ion exchange. By chemical strengthening in a molten salt bath (e.g., KNO3 or NaNCh), glasses with high strength, high toughness, and high indentation cracking resistance can be achieved. The stress profiles achieved through chemical strengthening may have a variety of shapes that increase the drop performance, strength, toughness, and other attributes of the glass-based articles. [0010] The glasses described herein can achieve high fracture toughness values (e.g., at least 0.75 MPa m) without the inclusion of additives, such as ZrCh, Ta2Os, TiCh, HfCh, La2O3, and Y2O3, that increase the fracture toughness but are expensive and may have limited commercial availability. In this respect, the glasses disclosed herein provide comparable or improved performance with reduced manufacturing costs. Fracture toughness and stress at depth are critical for improved drop performance on rough surfaces. For this reason, maximizing the amount of stress that can be provided in a glass-based article before reaching a frangibility limit increases the stress at depth and the rough surface drop performance. The fracture toughness is known to control the frangibility limit a