# US 11,112,833 B2 · Method for measuring fracture toughness of glass > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,112,833 B2 - Document ID: US11112833B2 - Status: Granted - Kind: B2 - Application number: 17/179,541 - Filed: 2021-02-19 - Published: 2021-06-17 - Granted: 2021-09-07 - Earliest claimed: 2018-05-31 - Assignees: Corning Incorporated - Applicants: Corning Incorporated - Inventors: Emily Marie Aaldenberg; Jared Seaman Aaldenberg - Web page: https://patentgrep.com/patent/US11112833B2 ## CPC - G06F 1/1656: {Details related to functional adaptations of the enclosure, e.g. to provide protection against EMI, shock, water, or to host detachable peripherals like a mouse or removable expansions units like PCMCIA cards, or to provide access to internal components for maintenance or to removable storage supports like CDs or DVDs, or to mechanically mount accessories (mounting of accessories to a computer display G06F1/1607; display hoods G06F1/1603; cooling arrangements for portable computers G06F1/203)} - C03C 3/085: containing an oxide of a divalent metal - C03C 3/087: containing calcium oxide, e.g. common sheet or container glass - C03C 3/093: containing zinc or zirconium - C03C 3/095: containing rare earths - C03C 3/097: containing phosphorus, niobium or tantalum - C03C 21/00: Treatment of glass, not in the form of fibres or filaments, by diffusing ions or metals in the surface - C03C 21/002: {to perform ion-exchange between alkali ions (C03C21/005 takes precedence)} - G01M 5/0033: {by determining damage, crack or wear} - G06F 1/1613: {for portable computers (cooling arrangements therefor G06F1/203; constructional details or arrangements for pocket calculators, electronic agendas or books G06F15/0216; constructional details of portable telephone sets: with several bodies H04M1/0202)} - H05K 5/0217: {Mechanical details of casings (covers, lids, hoods or members for covering apertures H05K5/03)} - G06F: ELECTRIC DIGITAL DATA PROCESSING (computer systems based on specific computational models G06N) - C03C: CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS - G01M: TESTING STATIC OR DYNAMIC BALANCE OF MACHINES OR STRUCTURES; TESTING OF STRUCTURES OR APPARATUS, NOT OTHERWISE PROVIDED FOR - H05K: PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS ## Abstract Glass-based articles are provided that exhibit improved drop performance. The relationship between properties attributable to the glass composition and stress profile of the glass-based articles are provided that indicate improved drop performance. ## Claims ### Claim 1 A method of measuring fracture toughness of glass, comprising: sub-critically growing a crack in a sample of a glass until a ratio of crack length to half of a width of the sample is greater than 1.5; after sub-critically growing the crack, pinning the crack; after pinning the crack, fracturing the sample by increasing load on the sample until failure; and calculating fracture toughness of the glass as a function of the load at failure and dimensions of the sample. ### Claim 2 (depends on 1) The method of claim 1, wherein the pinning comprises wicking an agent into the crack along a length of the crack. ### Claim 3 (depends on 2) The method of claim 2, wherein the agent is toluene. ### Claim 4 (depends on 1) The method of claim 1, wherein the sample is rectangular. ### Claim 5 (depends on 4) The method of claim 4, wherein a first thickness of the sample is between 0.3 mm and 1 mm. ### Claim 6 (depends on 5) The method of claim 5, wherein the sample comprises a web having a second thickness less than the first thickness. ### Claim 7 (depends on 6) The method of claim 6, wherein the second thickness is approximately half the first thickness. ### Claim 8 (depends on 7) The method of claim 7, wherein the dimensions used in calculating the fracture toughness include the first and second thicknesses. ### Claim 9 (depends on 8) The method of claim 8, wherein the fracture toughness is calculated by calculating applied stress intensity of the glass. ### Claim 10 (depends on 1) The method of claim 1, further comprising monitoring the crack. ### Claim 11 (depends on 10) The method of claim 10, wherein the monitoring includes using a microscope attached to a digital camera and computer. ### Claim 12 (depends on 1) The method of claim 1, wherein the sample comprises a guiding groove down a length of the sample. ### Claim 13 (depends on 12) The method of claim 12, wherein the sample has two major surfaces, and the guiding groove extends down both major surfaces and forms a web. ### Claim 14 (depends on 13) The method of claim 13, further comprising cutting an initial crack through the web and within the guiding groove. ### Claim 15 (depends on 14) The method of claim 14, wherein the cutting of the initial crack comprises using a dicing saw. ### Claim 16 (depends on 15) The method of claim 15, wherein the initial crack includes a wedge formed by curvature of the dicing saw. ### Claim 17 A method of measuring fracture toughness of glass, comprising: cutting an initial crack through a web and within a guiding groove of a sample of glass, wherein the sample is rectangular, a first thickness of the sample is between 0.3 mm and 1 mm, the sample has two major surfaces, the guiding groove extends down a length of the sample and down both major surfaces to form the web, wherein the web has a second thickness that is less than the first thickness, sub-critically growing a crack in the sample, wherein the crack is sub-critically grown until a ratio of crack length to half of a width of the sample is greater than 1.5; after sub-critically growing the crack, pinning the crack, wherein the pinning comprises wicking an agent into the crack along a length of the crack, wherein the agent is toluene; after pinning the crack, fracturing the sample by increasing load on the sample until failure; and calculating fracture toughness of the glass as a function of the load at failure and dimensions of the sample, wherein the dimensions used in calculating the fracture toughness include the first and second thicknesses, wherein the fracture toughness is calculated by calculating applied stress intensity of the glass. ### Claim 18 (depends on 17) The method of claim 17, wherein the cutting of the initial crack comprises using a dicing saw. ### Claim 19 (depends on 18) The method of claim 18, wherein the initial crack includes a wedge formed by curvature of the dicing saw. ### Claim 20 A method of measuring fracture toughness of glass, comprising: cutting an initial crack through a web and within a guiding groove of a sample of glass, wherein the sample is rectangular, a first thickness of the sample is between 0.3 mm and 1 mm, the sample has two major surfaces, the guiding groove extends down a length of the sample and down both major surfaces to form the web, wherein the web has a second thickness that is less than the first thickness, sub-critically growing a crack in the sample; after sub-critically growing the crack, pinning the crack, wherein the pinning comprises wicking an agent into the crack along a length of the crack, wherein the agent is toluene; after pinning the crack, fracturing the sample by increasing load on the sample until failure; and calculating fracture toughness of the glass as a function of the load at failure and dimensions of the sample, wherein the dimensions used in calculating the fracture toughness include the first and second thicknesses, wherein the fracture toughness is calculated by calculating applied stress intensity of the glass.