Method of phase quality control for glass ceramics in manufacturing

    公开(公告)号:US11204280B2

    公开(公告)日:2021-12-21

    申请号:US16804219

    申请日:2020-02-28

    Abstract: A method for determining crystal phases of a glass ceramic sample, including the steps of applying energy to the sample using an excitation source, detecting raw Raman spectral energy that is given off by the sample using a detector, wherein the raw Raman spectral energy includes peak values, determining a plurality of predetermined energy peaks based off a composition of the sample, superimposing the plurality of predetermined energy peaks over the raw Raman spectral energy, applying a baseline value between each predetermined energy peak, subtracting the baseline value from the raw Raman spectral energy, calculating corrected peak values based on the raw Raman spectral energy and baseline value, and determining the crystal phases of the glass ceramic sample based on the corrected peak values.

    METHODS OF IMPROVING THE MEASUREMENT OF KNEE STRESS IN ION-EXCHANGED CHEMICALLY STRENGTHENED GLASSES CONTAINING LITHIUM

    公开(公告)号:US20210140836A1

    公开(公告)日:2021-05-13

    申请号:US17157190

    申请日:2021-01-25

    Abstract: Methods of improving the measurement of knee stress in an ion-exchanged chemically strengthened Li-containing glass sample that includes a knee are disclosed. One of the methods includes compensating for a shift in the location of the TIR-PR transition location associated with the critical angle location, wherein the shift is due to the presence of a leaky mode. Another method includes applying select criteria to the captured mode spectra image to ensure a high-quality image is used for the knee stress calculation. Another method combines direct and indirect measurements of the knee stress using the mode spectra from multiple samples to obtain greater accuracy and precision as compared to using either the direct measurement method or the indirect measurement method alone. Quality control methods of forming the glass samples using measured mode spectra and related techniques for ensuring an accurate measurement of the knee stress are also disclosed.

    Chemically strengthened lithium disilicate-petalite glass-ceramics

    公开(公告)号:US11634360B2

    公开(公告)日:2023-04-25

    申请号:US17461126

    申请日:2021-08-30

    Abstract: Ion-exchanged glass ceramic articles described herein have a stress that decreases with increasing distance according to a substantially linear function from a depth of about 0.07t to a depth of about 0.26t from the outer surface of the ion-exchanged glass ceramic article from a compressive stress to a tensile stress. The stress transitions from the compressive stress to the tensile stress at a depth of from about 0.18t to about 0.25t from the outer surface of the ion-exchanged glass ceramic article. An absolute value of a maximum compressive stress at the outer surface of the ion-exchanged glass article is from 1.8 to 2.2 times an absolute value of a maximum central tension (CT) of the ion-exchanged glass article, and the glass ceramic article has a fracture toughness of 1 MPa√m or more as measured according to the double cantilever beam method.

    Methods of characterizing ion-exchanged chemically strengthened glasses containing lithium

    公开(公告)号:US10768143B2

    公开(公告)日:2020-09-08

    申请号:US16296560

    申请日:2019-03-08

    Abstract: Methods of characterizing ion-exchanged chemically strengthened glass containing lithium are disclosed. The methods allow for performing quality control of the stress profile in chemically strengthened Li-containing glasses having a surface stress spike produced in a potassium-containing salt, especially in a salt having both potassium and sodium. The method allows the measurement of the surface compression and the depth of the spike, and its contribution to the center tension, as well as the compression at the bottom of the spike, and the total center tension and calculation of the stress at the knee where the spike and the deep region of the stress profile intersect. The measurements are for a commercially important profile that is near-parabolic in shape in most of the interior of the substrate apart from the spike.

    Prism-coupling stress meter with wide metrology process window

    公开(公告)号:US10732059B2

    公开(公告)日:2020-08-04

    申请号:US16371517

    申请日:2019-04-01

    Abstract: The prism-coupling systems and methods include using a prism-coupling system to collect initial TM and TE mode spectra of a chemically strengthened article having a refractive index profile with a near-surface spike region and a deep region. The initial TM and TE mode spectra are examined to see if they fall within a preferred measurement window that can produce an accurate estimate of the knee stress to within a select tolerance. If not, then measurement configuration of the prism-coupling system is changed and new TM and TE mode spectra are collected. This process is repeated until the new TM and TE mode spectra fall within the preferred measurement window. The new TM and TE mode spectra are then used to determine the knee stress. Changing the measurement configuration can include changing at least one of the measurement wavelength, interfacing fluid thickness and interfacing fluid refractive index.

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