Glass articles exhibiting improved fracture performance
Embodiments of this disclosure pertain to a strengthened glass article including a first surface and a second surface opposing the first surface defining a thickness (t) of about less than about 1.1 mm, a compressive stress layer extending from the first surface to a depth of compression (DOC) of about 0.1·t or greater, such that when the glass article fracture, it breaks into a plurality of fragments having an aspect ratio of about 5 or less. In some embodiments, the glass article exhibits an equibiaxial flexural strength of about 20 kgf or greater, after being abraded with 90-grit SiC particles at a pressure of 25 psi for 5 seconds. Devices incorporating the glass articles described herein and methods for making the same are also disclosed.
1. A strengthened glass article comprising:
a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 mm or less;
a compressive stress layer extending from the first surface to a depth of compression (DOC) of greater than 0.16·t as measured by scattered light polariscope, the compressive stress layer comprising a surface compressive stress of 400 MPa or greater, as measured by a combination of scattered light polariscope and surface stress meter; and
a maximum central tension that is 50 MPa or greater as measured by scattered light polariscope,
wherein, after the glass article fractures according to a Frangibility Test, the glass article includes a plurality of fragments, wherein at least 90% of the plurality of fragments have an aspect ratio of about 5 or less.
2. The strengthened glass article of claim 1 , wherein the glass article fractures into the plurality of fragments in 1 second or less, as measured by the Frangibility Test.
3. The strengthened glass article of claim 1 , wherein at least 80% of the plurality of fragments have a maximum dimension that is less than or equal to 3·t.
4. The strengthened glass article of claim 1 , wherein at least 50% of plurality of fragments comprises an aspect ratio of 2 or less.
5. The strengthened glass article of claim 1 , wherein at least 50% of the plurality of fragments comprises a volume of less than or equal to about 10 mm 3 .
6. The strengthened glass article of claim 1 , wherein the plurality of fragments comprises an ejected portion of fragments, wherein the ejected portion of fragments comprises 10% or less of the plurality of fragments.
7. The strengthened glass article of claim 1 , wherein the glass article comprises a first weight prior to fracture and the wherein the plurality of fragments comprises an ejected portion of fragments and a non-ejected portion of fragments, the non-ejected portion of fragments having a second weight, and the difference between the first weight and the second weight is 1% of the first weight.
8. The strengthened glass article of claim 1 , wherein the probability of the glass article fracturing into the plurality of fragments within 1 second or less, as measured by a Frangibility Test, is 99% or greater.
9. The strengthened glass article of claim 1 , wherein the glass article comprises a stored tensile energy of 20 J/m 2 or greater.
10. The strengthened glass article of claim 1 , wherein the ratio of the maximum central tension to surface compressive stress is in the range from about 0.1 to about 1.
11. The strengthened glass article of claim 10 , wherein the maximum central tension is 100 MPa/√(t/1 mm) or greater (in units of MPa), wherein t is in mm.
12. The strengthened glass article of claim 1 , wherein the glass article comprises an alkali aluminosilicate glass, alkali containing borosilicate glass, an alkali aluminophosphosilicate glass or alkali aluminoborosilicate glass.
13. The strengthened glass article of claim 1 , wherein the glass article is disposed on a containment layer.
14. The strengthened glass article of claim 1 , further comprising:
a CT region of the stress profile, wherein the CT region is defined by the equation
Stress( x )=MaxCT−(((MaxCT·( n+ 1))/0.5 n )·|( x/t )−0.5| n ),
wherein MaxCT is the maximum CT value and is provided as a positive value in units of MPa, x is position along the thickness (t) in micrometers, and n is between 1.5 and 5.
15. A strengthened glass article comprising:
a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 mm or less;
a compressive stress layer extending from the first surface to a depth of compression (DOC) of greater than 0.2·t as measured by scattered light polariscope, wherein the surface compressive stress is 250 MPa or greater, as measured by a combination of scattered light polariscope and surface stress meter;
a maximum central tension of 85 MPa or more as measured by scattered light polariscope; and
wherein, after the glass article fractures according to a Frangibility Test, the glass article includes a plurality of fragments, wherein at least 90% of the plurality of fragments have an aspect ratio of about 5 or less.
16. The strengthened glass article of claim 15 , further comprising:
a CT region of the stress profile, wherein the CT region is defined by the equation
Stress( x )=MaxCT−(((MaxCT·( n+ 1))/0.5 n )·|( x/t )−0.5| n ),
wherein MaxCT is the maximum CT value and is provided as a positive value in units of MPa, x is position along the thickness (t) in micrometers, and n is between 1.5 and 5.
17. A strengthened glass article comprising:
a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 mm or less;
a compressive stress layer extending from the first surface to a depth of compression (DOC) of greater than about 0.15·t as measured by scattered light polariscope, the compressive stress layer comprising a surface compressive stress of 400 MPa or greater, as measured by a combination of scattered light polariscope and surface stress meter; and
a maximum central tension (CT) of about 50 MPa or greater as measured by scattered light polariscope,
wherein the glass article exhibits a load to failure of about 10 kgf or greater, after being abraded with 90-grit SiC particles at a pressure of 25 psi for 5 seconds.
18. The strengthened glass article of claim 17 , wherein the glass article comprises a stored tensile energy of 20 J/m 2 or greater.
19. The strengthened glass article of claim 17 , wherein the ratio of the maximum central tension to surface compressive stress is in the range from about 0.1 to about 1.
20. The strengthened glass article of claim 19 , wherein the maximum central tension (CT) is M 85 MPa or greater.
21. The strengthened glass article of claim 17 , wherein the DOC comprises about 0.2t or greater.
22. The strengthened glass article of claim 17 , wherein the glass article is adhered to a substrate.
23. The strengthened glass article of claim 17 , further comprising:
a CT region of the stress profile, wherein the CT region is defined by the equation
Stress( x )=MaxCT−(((MaxCT·( n+ 1))/0.5 n )·|( x/t )−0.5| n ),
wherein MaxCT is the maximum CT value and is provided as a positive value in units of MPa, x is position along the thickness (t) in micrometers, and n is between 1.5 and 5.
24. The strengthened glass article of claim 17 , wherein t is 0.4 mm or more.
25. A consumer electronic product comprising:
a housing having a front surface;
electrical components provided at least partially internal to the housing, the electrical components including at least a controller, a memory, and a display; and
a cover glass disposed at the front surface of the housing and over the display, or disposed as a back cover, the cover glass comprising a strengthened glass article,
wherein the strengthened glass article comprises:
a first surface and a second surface opposing the first surface defining a thickness (t) of about 3 mm or less;
a compressive stress layer extending from the first surface to a depth of compression (DOC) of greater than about 0.17 t as measured by scattered light polariscope, the compressive stress layer comprising a surface compressive stress of 200 MPa or more as measured by a combination of scattered light polariscope and surface stress meter; and
a maximum central tension (CT) of about 85 MPa or greater as measured by scattered light polariscope.
26. The consumer electronic product of claim 25 , wherein the glass article comprises a stored tensile energy of 20 J/m 2 or greater.
27. The consumer electronic product of claim 25 , wherein the ratio of the maximum central tension to surface compressive stress is in the range from about 0.1 to about 1.
28. The consumer electronic product of claim 25 , wherein the DOC comprises about 0.2t or greater.
29. The consumer electronic product of claim 25 , wherein the glass article is disposed on a containment layer.
30. The consumer electronic product of claim 25 , wherein the consumer electronic product comprises a tablet, a transparent display, a mobile phone, a video player, an information terminal device, an e-reader, a laptop computer, or a non-transparent display.
31. The electronic consumer product of claim 25 , further comprising:
a CT region of the stress profile, wherein the CT region is defined by the equation
Stress( x )=MaxCT−(((MaxCT·( n+ 1))/0.5 n )·|( x/t )−0.5| n ),
wherein MaxCT is the maximum CT value and is provided as a positive value in units of MPa, x is position along the thickness (I) in micrometers, and n is between 1.5 and 5.