Glass-based articles are disclosed having a thickness in a range of from about 0.2 mm to about 4.0 mm, a first compressive stress layer extending from a first surface of the glass-based article to a first depth of compression that is in a range of from about 5% to about 20% of the thickness, a second compressive stress layer extending from a second surface of the glass-based article to a second depth of compression that is in a range of from about 5% to about 20% of the thickness, wherein the second surface is opposite the first surface, and a central region extending from the first depth of compression to the second depth of compression and having a maximum tensile stress in a range of from about 0.5 MPa to about 20 MPa. Electronic devices comprising the glass-based articles and methods of making glass-based articles are also disclosed.

Glass-based articles are disclosed having a thickness in a range of from about 0.2 mm to about 4.0 mm, a first compressive stress layer extending from a first surface of the glass-based article to a first depth of compression that is in a range of from about 5% to about 20% of the thickness, a second compressive stress layer extending from a second surface of the glass-based article to a second depth of compression that is in a range of from about 5% to about 20% of the thickness, wherein the second surface is opposite the first surface, and a central region extending from the first depth of compression to the second depth of compression and having a maximum tensile stress in a range of from about 0.5 MPa to about 20 MPa. Electronic devices comprising the glass-based articles and methods of making glass-based articles are also disclosed.

Provided is alkali-free aluminoborosilicate glass. The glass is prepared by the following raw materials in percentage by weight: 60-72% SiO.sub.2, 13-18% of Al.sub.2O.sub.3, 8.5-10% of B.sub.2O.sub.3, 1-4.5% of MgO, 3-8% of CaO, 1-5% of SrO, 0.5-2% of ZrO.sub.2, 1-5% of P.sub.2O.sub.5, and 0.1-0.5% of SnO.sub.2, wherein SiO.sub.2+Al.sub.2O.sub.3 is 76-85%; (MgO+CaO+SrO)/Al.sub.2O.sub.3 is 0.4-0.7; the total amount of alkaline earth metal oxide is 5-11.5%; B.sub.2O.sub.3/(B.sub.2O.sub.3+ZrO.sub.2+P.sub.2O.sub.5) is 0.6-0.9; and (ZrO.sub.2+P.sub.2O.sub.5)/(MgO+CaO+SrO) is 0.15-0.8. The glass has the characteristics such as higher strain point, high Young modulus, high hardness, high specific modulus, proper thermal expansion coefficient, and low thermal shrinkage; the boron volatilization rate is as low as 5.6-10.5%, so that the phenomenon of component nonuniformity due to boron volatilization can be effectively controlled; and the glass is suitable for a float forming process, does not contain toxic substances such as As.sub.2O.sub.3 and Sb.sub.2O.sub.3, is environment-friendly, is suitable for large-scale industrial production, and is particularly suitable for glass substrates for LCD/OLED displays.

Provided is alkali-free aluminoborosilicate glass. The glass is prepared by the following raw materials in percentage by weight: 60-72% SiO.sub.2, 13-18% of Al.sub.2O.sub.3, 8.5-10% of B.sub.2O.sub.3, 1-4.5% of MgO, 3-8% of CaO, 1-5% of SrO, 0.5-2% of ZrO.sub.2, 1-5% of P.sub.2O.sub.5, and 0.1-0.5% of SnO.sub.2, wherein SiO.sub.2+Al.sub.2O.sub.3 is 76-85%; (MgO+CaO+SrO)/Al.sub.2O.sub.3 is 0.4-0.7; the total amount of alkaline earth metal oxide is 5-11.5%; B.sub.2O.sub.3/(B.sub.2O.sub.3+ZrO.sub.2+P.sub.2O.sub.5) is 0.6-0.9; and (ZrO.sub.2+P.sub.2O.sub.5)/(MgO+CaO+SrO) is 0.15-0.8. The glass has the characteristics such as higher strain point, high Young modulus, high hardness, high specific modulus, proper thermal expansion coefficient, and low thermal shrinkage; the boron volatilization rate is as low as 5.6-10.5%, so that the phenomenon of component nonuniformity due to boron volatilization can be effectively controlled; and the glass is suitable for a float forming process, does not contain toxic substances such as As.sub.2O.sub.3 and Sb.sub.2O.sub.3, is environment-friendly, is suitable for large-scale industrial production, and is particularly suitable for glass substrates for LCD/OLED displays.

A dental bulk block for a CAD/CAM machining process. The dental bulk block is a glass-ceramic block having a crystalline phase embedded in an amorphous glass matrix. The crystalline phase includes lithium disilicate as a main crystalline phase, no sub-crystalline phase exists, and the crystalline phase has a mean grain size of 0.01 to 1.0 μm and a crystallinity degree of 25 to 45%. The dental bulk block can improve machinability during cutting such as CAD/CAM machining in the state of a high-strength workpiece with high flexural strength, thereby reducing a tool resistance and a wear rate, increasing a tool life span, and reducing edge chipping during a machining process. In addition, a dental restoration with desired translucency variations can be manufactured through a simple process of machining a block and altering post-heat treatment conditions, and thus can be realized with various shades.

ZrO.sub.2-toughened glass ceramics having high molar fractions of tetragonal ZrO.sub.2 and fracture toughness value of greater than 1.8 MPa.Math.m.sup.1/2. The glass ceramic may also include also contain other secondary phases, including lithium silicates, that may be beneficial for toughening or for strengthening through an ion exchange process. Additional second phases may also decrease the coefficient of thermal expansion of the glass ceramic. A method of making such glass ceramics is also provided.

ZrO.sub.2-toughened glass ceramics having high molar fractions of tetragonal ZrO.sub.2 and fracture toughness value of greater than 1.8 MPa.Math.m.sup.1/2. The glass ceramic may also include also contain other secondary phases, including lithium silicates, that may be beneficial for toughening or for strengthening through an ion exchange process. Additional second phases may also decrease the coefficient of thermal expansion of the glass ceramic. A method of making such glass ceramics is also provided.

An article that includes: a substrate having a glass, glass-ceramic or a ceramic composition and comprising a primary surface; and a protective film disposed on the primary surface. The protective film comprises a thickness of greater than 1.5 microns and a maximum hardness of greater than 15 GPa at a depth of 500 nanometers, as measured on the film disposed on the substrate. Further, the protective film comprises a metal oxynitride that is graded such that an oxygen concentration in the film varies by 1.3 or more atomic %. In addition, the substrate comprises an elastic modulus less than an elastic modulus of the film.

An article that includes: a substrate having a glass, glass-ceramic or a ceramic composition and comprising a primary surface; and a protective film disposed on the primary surface. The protective film comprises a thickness of greater than 1.5 microns and a maximum hardness of greater than 15 GPa at a depth of 500 nanometers, as measured on the film disposed on the substrate. Further, the protective film comprises a metal oxynitride that is graded such that an oxygen concentration in the film varies by 1.3 or more atomic %. In addition, the substrate comprises an elastic modulus less than an elastic modulus of the film.

The present disclosure provides a method for coating a composite structure, comprising forming a first slurry by combining a first pre-slurry composition comprising a first phosphate glass composition, with a primary flow modifier and a first carrier fluid, wherein the primary flow modifier comprises at least one of cellulose or calcium silicate; applying the first slurry on a surface of the composite structure to form a base layer; and heating the composite structure to a temperature sufficient to adhere the base layer to the composite structure.